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SIM University

School of Science and Technology

Wideband, Low Loss and Compact 3D LTCC Balun with Asymmetric Structure for MIllimeter wave application

Student : N0805282

SUPERVISOR : Dr lum kum meng

Project Code : JUL2010/ENG/004

A project report submitted to SIM University

in partial fulfilment of the requirements for the degree of

Bachelor of Engineering (or Bachelor of Electronics)

May 2011

ABSTRACT

A Balun is an electrical transformer which convert electric signals that are balanced to an unbalanced and vice versa. The word “Balun” originated from the word Balance and unbalanced. Baluns can be in many forms and their presence is not always obvious, often using electromagnetic coupling for their operation.

The purpose of this thesis is to design a LTCC high performance balun that comes with a center frequency of 40 GHz. The proposed design comes in a 3D multilayer substrate with dielectric constant of 5.4 with embedded microstrip lines and coplanar strip lines.

The proposed design has an advantage of having a compact size due to its high frequency range. That is important in today’s technology as researches have being constantly on-going towards the trend of making competitive sizes. In this report, the advantages on the selection of Low Temperature Co-fired Ceramic (LTCC) and the types of microstrip and coplanar will be discussed.

The proposed balun was then customized and re-designed using FR-4 technology to illustrate the feasibility of the design methodology due to the budget constrain in this project, with a modified center frequency of 1.5GHz and dielectric constant of 4.7.

The software used to design and modify both the substrate here is ADS (Agilent Advanced Design Software). With the design and simulation function available in ADS, the proposed balun is first created with the calculated dimension and then modified with references to the simulation results provided in S-Parameters output format.

Acknowledgement

This final year Project is an accumulation of continuous effort by applying the knowledge obtained in the courses taught during my stay in SIM University.

Through the precious lesson conducted by the team of dedicated lecturers and tutors, I would like to thank them in imparting their knowledge and experience to the students wholeheartedly. The excellent work that the school provides for the students, I believe the success and growth of SIM University will continue to a greater height.

Lastly, i would like to express my sincere gratitude to my project supervisor, Dr Lum Kum Meng for keeping me on the right track of the project schedule with his tireless effort in planning frequent project meetings with his beloved project students. By not only sharing and giving his valuable experiences, he had sacrificed his precious time after lesson ends.

TABLE OF CONTENTS

Page

ABSTRACT i

ACKNOWLEDGEMENT ii

TABLE OF CONTENTS iii

LISTS OF TABLES vii

LIST OF FIGURES viii

CHAPTER ONE

INTRODUCTION 1

1.1 Background of Project 1

1.2 Project Objectives 1

1.3 Overall Objectives 1

1.4 Proposed Approach 2

1.4.1 Theoretical Approach 2

1.4.2 Simulation Approach 2

1.4.3 Technical Approach 2

1.4.4 Project Scope 3

1.4.5 Overall design approach flowchart 4

1.5 Skills Review 5

1.5.1 Criteria and Targets for accessing Targets 5

1.5.2 Skills required in Achieving Project Targets 5

1.5.3 Strength and weakness 5

1.5.4 Priorities for Improving Skills 6

1.6 Project Planning and Schedule 7

1.6.1 Gantt Chart 7

1.6.2 Resources Required 8

1.7 Outline of the Thesis 11

CHAPTER TWO

LITERATURE REVIEWS 12

2.1 Literature Review on LTCC Technology 12

2.1.1 Advantages of LTCC Technology 12

2.1.2 Process of LTCC Technology 13

2.1.3 LTCC Applications 14

2.2 Concept of Micro-strip line and Coplanar Strip Line 16

2.2.1 Micro-strip structure and Wave in micro-strip 16

2.2.2 Types of Microstrip Balun 16

2.2.3 Coplanar Strip Structure and Wave in Coplanar Strip 19

2.2.4 Types of CPS Balun 19

2.2.5 Fringing effects, effective electric constant and 20

characteristic Impedance

2.2.6 Guided wavelength and physical length of micro-strip 21

2.2.7 Analysis and synthesis Formula for Coplanar Strip lines 21

2.2.5 Lumped Capacitors 20

2.26 VIA Inductance 21

2.3 Basic Types of Balun 22

2.4 Literature Review on Millimeter Wave 24

2.5 Scattering Parameters 24

2.6 Network Analyzer 25

2.7 Agilent Advanced Design System 26

CHAPTER THREE

PROJECT SELECTIONS 27

3.1 Selection of Substrate Material 27

3.2 Selection of Software Simulator Tool 27

3.3 Selection of Measuring Equipment – Network Analyzer 28

3.4 Selection of Balun Design Topology 29

CHAPTER FOUR

FILTER DESIGN & SIMULATION USING LTCC 30

4.1 Initial Design of Band-pass Filter using LTCC technology 30

4.1.1 Setting up ADS 30

4.1.2 Port parameter in ADS 31

4.1.3 Calculation of Microstrip with Using LineCal 32

4.1.4 Obtaining Design Parameters 33

4.1.5 Design Implementation- Designing and Simulating the 35

Design Using ADS

4.1.6 Simulation Results of LTCC Balun with Modified 36

Dimension

CHAPTER FIVE

BALUN DESIGN & SIMULATION USING FR4 38

5.1 Initial Design of Band-pass Filter using FR4 technology 38

5.1.1 Setting up ADS 38

5.1.2 Setting up Port parameter in ADS 40

5.1.3 Calculation of Microstrip with Using LineCal 40

5.1.4 Obtaining Design Parameters 41

5.1.5 Design Implementation- Designing and Simulating the 44

Design Using ADS

5.1.6 Simulation Results of FR4 Balun with Modified 44

Dimension

CHAPTER SIX

Preparing For Fabrication 46

6.1 Exporting Gerber Files for Fabrication 46

CHAPTER SEVEN

7.0 Project Summary 48

7.1 Conclusion 48

7.2 Problems and Solutions 48

7.3 Suggestion for Future Work 49

REFERENCES 51

APPENDIX A – Agilent Network Analyzer E5062A 52

APPENDIX B – Project Meeting Logs 55

APPENDIX C – Simulation Results for LTCC Calculated Dimension 65

APPENDIX D – Simulation Results for FR4 Calculated Dimension 66

LIST OF TABLES

TABLE NO. TITLE PAGE

    1. Gantt Chart 7

1.2 Resources required for the project 8

2.1 List of LTCC applications 15

3.1 Factors to consider in the selection of substrate materials 27

3.2 List of substrate material used in tn the project 27

3.3 Measurement capabilities of E5062A 28

3.4 Type of Micro-strip filters and their resonator length 38

4.1 Taper Angle Selections 35

7.1 Results of LTCC balun and FR4 balun 48

LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.1 Flowchart of the overall design approach 4

1.2 Gantt Chart 7

2.1 A simple introduction of LTCC 12

2.2 Overall process of LTCC Technology 13

2.3 Micro-strip structure 16

2.4 Waves in micro-strip structure 16

2.5 Simple coupled line balun 17

2.6 A simple edge coupled balun with multiple coupled lines 17

2.7 A Coupled line balun that using broadside coupler structure 17

2.8 Simplest form of Marchand Balun 17

2.9 Tapered Microstrip 18

2.10 Configuration of a CPS 19

2.11 Electric and magnetic field distributions in CPW 19

2.12 Coplanar stripline-to-coplanar waveguide transition with three 20

Strip transmission lines

2.13 Configuration of a CPS 21

2.14 Schematic diagram of a L-C balun 22

2.15 Push pull amplifier will wire wound balun 23

2.16 Push pull amplifier that use of lumped components 23

2.17 Differences of 2 coaxial cable that provide different ratio of 24

impedance transformation

2.18 Figure explaining S11 24

2.19 Figure explaining S21 25

2.20 Figure explaining S12 and S22 25

3.1 Photo of Agilent Network Analyzer E506A 28

3.2 3D LTCC with multi-layers microstrips and CPS Lines 29

4.1a Creating substrates layers in ADS 30

4.1b Declaration of layout layers 31

4.1c Setting of simulation parameters 31

4.1d Ports Properties parameters 32

4.2 Linecal function in ADS 33

4.3 CPS calculation on LineCal 34

4.4 Configuration of a CPS 34

4.5 Overall design of a balanced LTCC Balun 36

4.6a Return loss and Insertion loss results from a LTCC balanced 36

back to back transition

4.6b Return loss and Insertion loss results from a LTCC unbalanced 37

back to back transition

5.1a Snap shot of the creation of multi-layers FR4 substrate with its

parameter 38

5.1b Snap shot of dielectric layer declaration 39

5.1c Software Simulation setup 39

5.1d Snap shot of Port properties settings 40

5.2 Calculation of Microstrip using LineCal 41

5.3 CPS calculation on LineCal 42

5.4 Configuration of a CPS 43

5.5a Return loss and insertion loss results from a balanced back to

Back transition 44

5.5b Return loss and insertion loss results from a unbalanced back to

Back transition 45

6.1 Export function in ADS 46

6.2 File creation destination directory folder 47

6.3 File Format/Output Unit selection 47

6.4 Snap shot of pop out when file is created 47

7.1 CPS taper angle 48

7.2 Final design 49

CHAPTER 1: INTRODUCTION

1.1 BACKGROUND OF PROJECT

In today’s context, the usage of millimetre systems such as WLAN (38-60GHz), WLL, automotive radar, are steadily increasing in demand. Even with the high cost in designing these systems, millimetre wave application are still actively in used due to its high capabilities in data transfer.

Having a high cost in developing millimetre wave applications, research has being carried out in search for a lower cost alternative. LTCC, capable to design in 3D multilayer and high integration for passive devices turns out to be very popular in the choice. Its features have lead to a significant drop in manufacturing cost with a smaller size. Low loss LTCC dielectrics have been developed and are in favourites as the best choice in high frequency applications [1]-[2].

With the introduction of wideband Marchand balun [3], microwave devices such as balanced mixer and antenna feeding has taken a step further. Reports [4]-[5] are investigated in this type of balun design using CPS lines with an extended ground plane required to insure the proper behaviour of this balun. In case of a microstrip Marchand type balun, broadside electromagnetic coupling is generally not strong enough. Further investigations [6]-[7] have been pursued to look for an improvement in the coupling coefficient. Vertical coupling can achieve higher coupling coefficient than broadside coupling. Furthermore, stacked 3D structure leads to size reduction of the device. LTCC multilayer features are well suited for this structure but the design at millimeter wave frequencies remains a huge challenge due to the design rule limitations. LTCC baluns [8]-[9] have been reported, but these baluns operated at C-band or lower frequency ranges. Millimeter wave baluns [10]-[11] have been reported. These designs have high insertion losses because they were fabricated on a high loss semiconductor wafers such as GaAs.

We present a compact and wideband millimeter wave 3D LTCC balun using multi-layer microstrip and CPS line embedded in low loss LTCC dielectrics. The proposed balun operates over a wider band than the conventional type.

1.2 PROJECT OBECTIVES

The main objective of this project is to design a compact 3D LTCC Balun with an asymmetric structure for millimeter wave applications. Design should be operated with wide band and low insertion loss.

1.3 OVERALL OBECTIVES

This includes the following scopes:

  • Evaluating existing Millimeter Wave applications

  • Research and understand literature review on LTCC technologies

  • Research and understand literature review on the Balun design

  • Design and simulate LTCC Balun using ADS(Agilent Advanced Design System)

  • Edit and modify the design using FR-4 substrate instead of LTCC

  • Fabrication of the design

1.4 PROPOSED APPROACH

To begin the project, we have to first understand the description of the project. Understand the needs and the demand for the applications. These understanding comprises of theoretical researching of the technologies. Followed by using ADS to design and simulate. And once the design meets the requirements, we will proceed with the fabrication.

  1. Theoretical approach

  2. Simulation approach

  3. Technical approach

Elaboration of each approach details and discussion are listed below.

1.4.1 Theoretical Approach:

Theoretical approach is one of the core components to ensure success of this project. Initial phase includes detailed research, examination and understanding of various technology and resource required.

The following researches to be done are:

  1. Literature review on multilayer LTCC technology

  2. Literature review on asymmetric Balun design methodology

  3. Multilayer microstrip and Coplanar strip lines for Balun design

  4. S Parameters for input to output reflective coefficient

  5. Usage and advantages of Advanced Design System (ADS)Software

  6. Features and functions of Network Analyzer

1.4.2 Simulation Approach

In this approach, we make use of the ADS software to help us design and simulate out the project design to meet the requirements of the application. It will be based on the simulation results to analysis the design needs.

Steps required to obtain the desired results are:

  • Determine which balun design is suitable for the millimeter wave application

  • Drafting the range of dimension for the design

  • Design and model the proposed design using multi layers of LTCC with ADS software

  • Analysis the results of the simulation and thus selecting the design with the least insertion loss(S-parameter)

1.4.3 Technical Approach

Technical Approach involved hardware fabrication of the proposed balun using FR-4 substrate, performing technical analysis on the measured and simulation results and project enhancement to further improve the proposed design performance.

Steps required to obtain the desired Balun design on FR-4 are:

  • Lower the frequency requirement to 1.5GHz to suit the frequency range provided by the network analyzer

  • Modify the design substituting FR-4 for LTCC

  • Compute and analyze the simulation results of the FR-4 Fabricate the hardware of the design with FR-4

  • Compare and measure the differences of results obtain from ADS simulation and the network analyzer

1.4.4 Project Scope

The under-mention states the project scope:

  1. Evaluating existing balun design methodologies

  2. Evaluating and understand literature review on LTCC technology

  3. Design of balun using LTCC (Dielectric constant and thickness)according to specification

  4. Obtain simulation result using ADS software

  5. Fabrication of the balun design

  6. Present comparison between the simulated and measured balun design

  7. Evaluating the need for further modification / expansion to the completed project

1.4.5 Overall design approach flowchart

The overall design approach is presented by the following flowchart:

Figure 1.1: Flowchart of the overall design approach

1.5 SKILLS REVIEW

1.5.1 Criteria and Targets for accessing targets

The criteria and targets of the project will set based on our project requirement with the proposed project approaches and methods.

According to scheduled project plan, the targets will be set and the progress of the project will be monitored thru the Gantt chart.

1.5.2 Skills required in achieving project targets

It is important to know what types of skills to apply to this project. So making a list enable myself to be wary of the necessary skills that I need to acquire:

  1. Knowledge in LTCC technology

  2. Knowledge in Balun design

  3. Knowledge in combining the LTCC Balun Technology

  4. Understanding the functions of Agilent Advanced Design Software (ADS)

  5. Able to understand and use the functions of Network Analyzer

  6. Scattering Parameters

  7. Microstrips and Co-Planar Strips lines

  8. Power Divider/Spitter

  9. Knowledge in Linear Systems Analysis and Design (ENG 201)

  10. Knowledge in Filter Theory and Design (ENG 203)

  11. Knowledge in Further Mathematical Methods and Mechanics (MTH 215)

  12. Knowledge in Numerical Methods and Advance Calculus (MTH 217)

  13. Knowledge in Fundamentals of Statistics and Probability (MTH 219)

  14. Knowledge in Digital Signal Processing (ENG 311)

  15. Knowledge in Adaptive Signal Processing (ENG 313)

  16. Knowledge in Wireless Communication System (ENG 315)

  17. Knowledge in Optical Communication System (ENG 317)

  18. Knowledge in Electronic Engineering Innovation and Design (HESZ 331)

1.5.3 Strength and weakness

Strength:

  • Subjects such as Linear Systems Analysis and Design, Filter Theory and Design, Digital Signal Processing and Adaptive Signal Processing in Unisim have assisted me constructively in my understanding of the design methodology and analysis.

  • Having completed Electronic Engineering Innovation and Design in Unisim helps me understand the important of project management skill and planning.

  • Having completed lab courses like Logic Design and VLSI, helps me understand and use ADS software in a similar way.

  • With the help of my project supervisor, regular meetings were being held thus ensuring schedule of the project to be carried out on time and in the right direction.

Weakness:

  • Knowledge needed on LTCC technology

  • Knowledge needed on Balun technology

  • Understand the current LTCC Balun limitations

  • Need to find out more on the important parameters affecting the design insertion loss and return loss

  • Familiarize with ADS designing tool for multi layers design

  • Knowledge in the design parameters that affect the simulated results

  • Understand the features and functions of Network Analyzer, including the range of frequency it provide

1.5.4 Priorities for improving skills

Setting priorities are important to kick start the project. In order to structure systematic thinking of accomplishing the project, the below shows actions that are being carried out to ensure the basic are in place:

  1. Understanding the requirement of the project title

  2. Finding out what LTCC technology can do and its advantages

  3. Reading out the literature review on Balun that consisting of embedded multi layers microstrips and Coplanar strips lines.

  4. Familiarize with ADS software and understand which design parameters are affecting the simulation results.

  5. Able to effectively analysis the simulated results for selecting the best proposed design

1.6 PROJECT PLANNING AND SCHEDULE

1.6.1 Gantt Chart

Table 1.1: Gantt Chart

1.6.2 Resources Required

Table 1.3 shows the resources required for the completion of this project.

Resources Required

Availability

Reference books

  1. RF Circuit Design- Theory and Applications (R.Ludwig, P. Bretchko)

  2. Field and Wave EM 2nd Edition (David K Cheng)

  3. Microstrip Lines and Slotlines 2nd Edition (Bhartia Bahl Garg Gupta)

  4. K. Watanabe, K. Nakayama and H. Usui, “An investigation of

the properties of new-developed LTCC materials for their use in

microwave circuit,” Proceedings of 2002 IMAPS, pp. 389-393,

Nov. 2002.

  1. S. Watanabe, K. Nakayama and K. Watanabe, “An investigation

of the properties of newly developed LTCC materials for their

use in microwave antenna,” Proceedings of 2003 IMAPS, pp.

453-458, Nov. 2003.

  1. N. Marchand, “Transmission line conversion transformers,”

Electronics, vol.17, no.12, pp.142-145, Dec. 1944.

  1. N. Michishita, H. Arai, M. Nakano, T. Satoh and T. Matsuoka,

“FDTD analysis for printed dipole antenna with balun,” 2000

Asia Pacific Microwave Conference, pp. 739-742, Dec. 2000.

  1. N. Michishita, H. Arai, K. Tsunekawa and M. Karikomi,

“FDTD analysis of dual frequency printed dipole antenna,”

2002 IEEE Antennas and Propagation Society International

Symposium, vol.2 , pp. 40-43, Jun. 2002.

  1. C. Choonsik and K. C. Gupta, “A new design procedure for

single-layer and two-layer three-line baluns,” IEEE Trans.

Microwave Theory and Tech., vol. 46, no. 12, pp. 2514-2519,

Dec. 1998.

  1. K. S. Ang and I. D. Robertson, “Analysis and design of

impedance-transforming planar Marchand baluns,” IEEE Trans.

Microwave Theory and Tech., vol. 49, no. 2, pp. 402-406, Feb.

2001.

  1. Y. Qian and T. Itoh, “A Broadband uniplanar Microstrip-to-CPS

Transition,” 1997 Asia Pacific Microwave Conference,, pp. 609-

612, 1997.

  1. Y. Fujiki, H. Mandai and T. Morikawa, “Chip type spiral

broadside coupled directional couplers and baluns using low

temperature co-fired ceramic,” 49th Electronic Components and

Technology Conference Proceedings, pp. 105-110, Jun. 1999.

  1. K. S. Ang and I. D. Robertson, “Analysis and design of

impedance-transforming planar Marchand baluns,” IEEE Trans.

Microwave Theory and Tech., vol. 49, no. 2, pp. 402-406, Feb.

2001.

  1. K. Nishikawa, I. Toyoda and T. Tokumitsu, “Compact and

broad-band three-dimentional MMIC Balun,” IEEE Trans.

Microwave Theory and Tech., vol. 47, no. 1, pp. 96-98, Jan.

1999.

  1. ] K. S. Ang and I. D. Robertson, “A millimeter-wave monolithic

sub-harmonically pumped resistive mixer,” 1999 Asia Pacific

Microwave Conference, vol. 2, pp. 222-225, Nov. 1999.

  1. L. Chen, S. -F. Chang and B. -Y. Laue, “A 20-40 GHz

monolithic doubly-balanced mixer using modified

planar

Marchand baluns,” 2001 Asia Pacific Microwave

Conference,

vol. 1, pp. 131-134, Dec. 2001.

ADS Software

Free trial version of ADS software with renewable is available at

Network Analyzer

Available in SIM University Laboratory

Table 1.2: Resources required for the project

1.7 OUTLINE OF THE THESIS

The thesis consists of seven chapters and the overviews of each chapter are as follows:

Chapter 1: The first chapter provides readers a brief introduction on the project background, the objectives, proposed approach, skills review, project planning and schedule.

Chapter 2: This chapter shows the literature reviews on LTCC, Microstrip Baluns, Millimetre wave, the scattering Parameters, network analyzer and Agilent Advanced Design System software. Though this chapter, reader is able to understand the topologies used later which includes the advantages and benefits of the discussed topics.

Chapter 3: This chapter discuss the selected types of substrate material, microstrip line, Coplanar strip line, software, network analyzer and its reasons.

Chapter 4: Step by step instruction for setting up the ADS software by input the design parameters. This chapter covers the design methodology and simulated results for the initial balun design by using formula calculation and thus improving the design with LTCC substrate.

Chapter 5: From the previous chapter, continue on the modify design with FR4 substrate. Show the results for calculated and improved version of the dimension and simulated results.

Chapter 6: Shows reader on how to import the Gerber file from the ADS design which is essential to vendor when fabricating the hardware. Includes step by step instruction used in ADS function extracted from design to obtain the Gerber file.

Chapter 7: In this last chapter, it presents the conclusion of the thesis which includes the summary, problems and solution and suggestion for improvement.

CHAPTER 2: LITERATURE REVIEWS

2.1 Literature Review on LTCC Technology

Low temperature Co-fired Ceramic (LTCC) used in the microelectronics high packaging industry has being well-established over the years. Each of the layers, made from multi- layers ceramic dielectric tape and screen printing of conductors materials like silver or gold on the green ceramic tape. LTCC are design to process in parallel and only brought together in an accurately aligned stack immediately prior to firing. LTCC technology is widely used in RF and high frequency applications due to its lower cost and capabilities in interconnecting thick film hybrid and components.

Figure 2.1 – A simple introduction of LTCC

2.1.1 Advantages of LTCC Technology

In the search for higher integration capabilities of passive devices in high frequency applications, LTCC have become very popular in recent years. LTCC process is almost similar to HTCC only that the ceramic is fired below 1000 °C makes it capable to use conductors like Silver, Gold and Copper instead of tungsten and molybdenum. This however enables LTCC to have a big advantage over HTCC.

LTCC capabilities of integrating passive components (resistors, capacitors and inductors) makes it a better choice when design dimension have being reduced and more compact with its 3D design thus having a lower manufacturing cost. And also layers are produced in parallel, resulting in shorter fabrication time.

LTCC avoid the disadvantage others have and offers couple of benefits listed below:

  1. Combining multiple manufacture processes compared with the conventional thick film technology (parallel processing);

  2. Fabrication methods for the module are simple and inexpensive;

  3. Tapes of different compositions can be manufactured with desired layer properties;

  4. Circuits with integrated component;

  5. Design possible with 3-Dimensional circuits;

  6. Possibility design on cutting the tape / substrate into different shapes and sizes;

  7. Capable for burying passive components within the substrate, size of circuits are greatly downsize

  8. Amount of layers almost unlimited;

  9. Ability to perform at very high frequencies;

  10. High resistance against ambient working temperatures (up to 350°C);

  11. Hermetic packaging

  12. High resistance against ambient working temperatures(up to 350C) due to it low Temperature Co-efficient of Expansion (TCE) and elastic reversible behavior

2.1.2 Process of LTCC Technology

This section will illustrate the process of LTCC technology. Fig 2.2 show the various process in LTCC technology.

Figure 2.2: Overall process of LTCC Technology

Slitting-

Firstly the greensheets are arrived on a roll. The tape will be unrolled onto a clean, balanced table (preferred to be stainless steel). This sheet will then be cut with razor, laser or punched into parts larger than the blank size if the material needs to be preconditioned- meaning that the greensheets has to be baked first depending on the manufacturer and material. If/when a laser is used to cut the sheets, it is necessary to control the power as to prevent firing onto the sheets.

Via punching –

Vias can be process either by punching method or drilled with a laser equipped with low power.

Via Filling –

Vias will then be filled with a conventional thick film screen printer or an extrusion via filter.

In using the conventional thick film screen printer, the tape has to be placed on a sheet of paper which lays on a porous stone and a vacuum pump that holds the tape in place and used as an aid for via filling. As for a using an extrusion via filter,the pressures is set about 4-4.5 bar psi. Both these methods need to have mak, that should be made if 150-200mm thickness of stainless steel. Or to use the Mylar foil, where the tape is be applied with.

Printing the conductive Lines –

The use of a conventional thick film screen printer is used to print the co-fireable conductors. These screens are of standard (250 – 350 emulsion type thick film screens.) The porous stone is also used here to hold the tape in place.

With the advantages of flatness and solvent absorption, alumina is commonly used over standard thick film to print conductors. One point to note is that resistors may vary their value when they are terminated with different conductors. But with the help of a Micro-Screen printer, it is possible to print conductors with 50mm line resolutions.

Lamination-

Before lamination take place, each layer is placed in turns over tooling pins. Where some processors may use a heat plier to fix the sheets in turns one on top of the other.

There are 2 possibilities of methods used to laminate the tapes. The first is called uniaxial lamination; tapes are pressed between heated platens at 70 °C, 200 Bar for 10 minutes. While rotating those 180 ° after 5 minutes. This process could cause some problems with cavities or the windows.

The second method is to use an isostatic press to stack the tapes into vacuum package in a foil that is pressed in hot water with the same condition as uniaxial press, keeping the pressure about 350 Bar

Cofiring -

Laminates are fired in one step on a smooth, flat setter tile. The firing follows a specific firing profile which is done with the help of a programmable box kiln.

A general profile show a gradual rising temperature slope about 2-5 °C in a minute up to 450 °C in a dwell time between one to two hours before the organic burnout(binder) takes place. Following a temperature to rise up to 850 – 875 °C depending on the materials and sizes.

PostFiring-

This postfiring is only done depending on the material used and varies in a wide range. Involving paste to be applied after the cofiring and need to be fired once more.

Singulation –

This process cut the laminates into smaller pieces or designated shapes. The most commonly used methods are using post fire dicing saw, ultrasonic cutter or by laser cut. These three methods are designed to suit different aspect tolerances and quality of the edges.

2.1.3 LTCC Applications

The technologies of LTCC has be greatly important in design various electronics applications. In the modern days, circuits, modules and antennas have being developed and nearly most of the activities are related to devices in communication or sensor applications due to its capabilities to suit a wide frequency ranges. The usages of LTCC in these applications includes from mobile communication, WLAN or Bluetooth, as well as in the military, where aerospace equipments in radar sensing with RF frequencies.

Application

Frequency

Photo

Dual band Amplifier

900-1800 MHz

Balanced push-pull amplifier

GSM

Bluetooth module with integrated antenna

2.45GHz

Divider networks for satellite application

17 – 21 GHz

FMCW radar sensor

24 GHz

Chip integration of LNA

20 – 32 GHz

Edge coupled bandpass filter

24.125, 25.5 GHz

Shielded strip-line bandpass filter

24.5, 25.5 GHz

Point to point transceiver module

27.5 – 29.5 GHz

Transitions from panar to rectangular waveguide

30 -35 GHz

Table 2.1 List of LTCC applications

2.2 Concept of Micro-strip line and Coplanar Line

In this section we are discussing about the planar transmission structures of microstrip lines and coplanar line strip that most microwave integrated circuits uses. These lines add to the flexibility of circuit design and improve the performance for some circuit functions such as controlling the design impedance by adjusting the width of the microstrip.

These lines are designed as of an electrical transmission line that is used to convey frequency signals.

      1. Micro-strips structure and Wave in micro-strip

In Fig 2.3, shows the general structure of a microstrip which consist of its width W and thickness T. The microstrip is placed on top of a dielectric substrate that has a thickness H and a relative thickness of εr. And a ground plane is placed at the bottom of the substrate.

Figure 2.3: Micro-strip structure

The Figure 2.4 below shows the fields in the microstrip that are extended within two media consist of the air on the top and dielectric on the second layer. The combination of these two layers causes the microstrip structure to become inhomogeneous. This in term modifies the mode of the propagation to a non-TEM hybrid mode and velocities to be dependent on the material properties, giving the permittivity ε and the permeability μ.

Fig 2.4: Waves in micro-strip structure

2.2.2 – Types of Microstrip Balun

There are wide selections of microstrip baluns topologies in the market with each having their various advantages of being inexpensive but on the other hand, its disadvantage is that it can be quite large in its area, particularly at lower frequencies range. In this section, we take a look at some of the commonly balun topologies in the market.

Figure 2.5 - Simple coupled line balun

For the simplest balun available in the market is the coupled line balun, also called a parallel-line balun shown in Figure 2.5. This structure is of a wavelength of a quarter long at the centre frequency. It has an advantage of obtaining bandwidths of over an octave when the coupling between the coupling between the lines are high enough.

Figure 2.6 – A simple edge coupled balun with multiple coupled lines

A more practical approach is to use multiple coupled lines where multi-layer substrate processing is in used shown in the above Figure 2.6. By achieving a broadside-coupler, shown in Figure 2.7, the implementation of the broadside-coupled is often referred to a parallel plate balun.

Figure 2.7 – A Coupled line balun that using broadside coupler structure

The improved version of the parallel-line balun is the Marchand Balun. The design comes from the co-axial balun, by Nathan Marchand in 1944. This printed version of the Marchand balun has more tolerant to low even mode impedance (low coupling ratio) than the parallel line balun and comes with a wider bandwidth, shown in Figure 2.8.

Figure 2.8 – Simplest form of Marchand Balun

To further improved the above parallel baluns, multiple planar section or a broadside coupling topology can be used to obtain an improved performance. With the setback due to its sizes when used in lower RF frequencies, the use of broadside coupling rather than edge coupling in parallel line and Marchand baluns improves the performance of the balun.

Tapered Microstrip Balun

Tapered microstrip balun is normal used as an impedance transformer network in feeding sections of spiral antennas as it provides excellent impedance transformation over a large range of frequencies. Due to its structure, it also converts a single ended port to a symmetric port. A gradual change of its cross section line makes the balun design capable to converts unbalanced to balanced and vice versa.

Figure 2.9 – Tapered microstrip

As shown in the above Figure 2.9, a tapered microstrip involve with two tapered lines etched on both side of the substrate. The first line is of at least three times wider than the other line at the unbalanced end, with these two lines together forms a microstrip line. At the balanced end, the lines are of the same width and in parallel strips. The cross section of the input line resembles microstrip, while the output strips are of equal width, making it a balanced line.

To design a tapered microstrip balun, the characteristic impedances of the line over at the input and output ports is needed. The known impedance at the balanced end is calculated according to its requirement and so the widths if the parallel strips at this end can be found using the equation of the selected taper. This followed by calculating the length of the taper by the specific criteria based on each taper. The structure is then simulated by any EM modelling software where the impedances at the respective ports will be realised. The widths are adjusted and procedures are repeated until the results are agreed with the desired results.

      1. Coplanar Strip structure and Wave in Coplanar strip

The term coplanar line is used for those transmission lines where all conductors are in the same plane, unlike Microstrip where only the bottom surface is placed with the ground plane. The main advantage over the other transmission structure is that the mounting of lumped components in shunt or series configuration is much easier; drilling of holes through the substrate is not needed to reach the ground plane. Thus the performance of CPS can sometimes be better than microstrip line in the form of guide wavelength, dispersion and losses.

Figure 2.10- Configuration of a CPS

In Figure 2.10 shows the configuration of a CPS which consist of 2 strips which have equal width W on a dielectric substrate where the S denoted the gap in between the 2 strips. CPS is preferred to be used in this project due to its capability to suit a substrate with higher thickness of substrate prefer to use CPW instead.

Figure 2.11- Electric and magnetic field distributions in CPW

2.2.4 Types of CPS Balun

Coplanar Stripline-to-Coplanar Waveguide Balun

In microwave circuits, a balun is required to interconnect a balanced transmission line to an unbalanced, such as a coplanar stripline (CPS) to a coplanar waveguide (CPW).

Figure 2.12 illustrate a CPS to CPW balun[15]. In this particular design, the balanced end currents of equal magnitude but opposite direction flow along the center strip conductors and the ground planes on either side. Through placing a short circuit between conductors 1 and 2, the balanced end gives an open circuit equals to an open circuit quarter wavelength away from the unbalanced end, forcing all current to flow to conductors 2 and 3. Thereby, conductors 1 and 3 are then shorted at the unbalanced end by using wire bonding. This short circuit appears as an open circuit a quarter wavelength away at the balanced end resulting conductor 1 to be isolated away from the balanced end.

This transition between the balanced and unbalanced end serve as a balun providing impedance transformation. Since RF signal propagates between conductors 2 and 3, the characteristic impedance between these three conductors determines the impedance transformation over the quarter wavelength section. By [16] the application of this transition to a CPW for a dipole antenna is demonstrated

Figure 2.12 -Coplanar stripline-to-coplanar waveguide transition with

three strip transmission lines.

      1. Fringing effects, effective electric constant and characteristic

impedance

Fringing effect occurs whenever the length or width of a microstrip is smaller compare to the height of the substrate. This causes the behaviour between the electric fields and the dielectric air interface to vary.

It causes the electric fields between the dielectric-air interfaces to vary, which resulted in a drift in the resonant frequency. Therefore, to minimising the fringing effect, the effective dielectric constant εr has been introduced with Zc illustrated by [13] are as followed,

For narrow micro-strip, W/h 1:

where ohms is the wave impedance in free space

For wide micro-strip, W/h 1:



      1. Guided wavelength and physical length of micro-strip

Since the effective dielectric constant εr has been obtained, the physical length l, of the microstrip can now be computed based on the type of microstrip been used stated in Eqn(4) or Eqn(5);

Where,

(3)

where is the guided wavelength and is the free space wavelength of the operating frequency f.

For half wavelength micro-strip:

l = λg / 2 (4)

For quarter wavelength micro-strip:

l = λg / 4 (5)

      1. Analysis and Synthesis Formulas for Coplanar Strip Lines

A Coplanar strip with a finite dielectric thickness configuration is shown in Figure 2.13, where it is make up of parameters of slot width S, strip width W, substrate thickness H, and the relative dielectric constant εr.

Figure 2.13- Configuration of a CPS

Due to the growing popularity in using coplanar waveguides (CPW) and Coplanar Strip lines (CPS) for hybrid and monolithic microwave integrated circuits design, it is important to understand the relationship between the characteristic impedance Zo and effective dielectric constant εeff [14].

(6)

Where k in Eqn (6), k’ in Eqn (7) and k1 in Eqn (8) are used to calculate the effective dielectric constant εeff in Eqn (9).

(7)

(8)

(9)

2.3 Basic type of Balun

L-C Balun

This design is also known as lattice type balun which consists of two capacitors and two inductors used to produce the ±90 degree phase shifts.

Figure 2.14 Schematic diagram of a L-C balun

At operating frequency,

When designing this circuit, the operating frequency has to be kept below the self resonant frequencies of the components and taking account of pad capacitances.

This design main application is on the output of a push pull amplifier, which is to provide a balanced signal converting into a single port unbalanced output. Usually by a wound toroid style balun is used.

Figure 2.15

The above Figure 2.15 shows a push pull amplifier that uses of wire wound balun on the output side to provided a balance to unbalanced conversion

Figure 2.16 showing a similar push pull amplifier that use of lumped components instead of a wire wound transformer

Transmission line

This design is realized from a λ/4 length of line or coax. Widely uses in applications like television receiver and antenna.

Figure 2.17 shows the differences of 2 coaxial cable that provide different ratio of impedance transformation

2.4 Literature Review on Millimeter Wave

Millimeter wave is the highest radio frequency band of 30 to 300 gigahertz. This band has wavelength of one to ten millimeter. In wireless communication, frequency is an important resource. By the use of millimeter wave technology, better efficiency will be resulted as higher frequencies means shorter wavelengths. Making applications like the antenna become millimeter size without affecting its capabilities of transmitting and receiving radio signals.

Future usage of this technology can even be home based electronic applications like wireless technology used at home or office such as multimedia contents downloads, HDTV streaming and instant data transfer.

2.5 Scattering Parameters

S parameters are used to describe an electrical network that will change according when frequency/load impedance/source impedance/network changes. These parameters are important in all RF systems derived that the fact that a practical system characterization can no longer be accomplished just by a simple open or short circuit measurements.

There are 4 parameters in S parameters namely, S11, S12, S21 and S22

Given a 2 terminals at both ports shown in the figure below,

Figure 2.18

S11, refers to the signal reflected at port1 for the signal incident at port1. Given by the ratio, b1/a1

Figure 2.19

S21 refers to the signal exiting at port2 for the signal incident at port1, given by the ratio, b2/a1

Figure 2.20

S12, refers to a signal exiting at port 1 over an incident signal at port 2 given by the ratio of, b2/a2

S22, refers to a signal exiting at port2 for an incident signal at port2 given by the ratio of, b2/a2

2.6 Network Analyzer

A networks analyzer is a measurement instruction that measures the network parameters of electrical networks. Because the reflection and transmission of electrical networks are easy to measure at high frequencies, S parameters is commonly used to reflect the results. However there are also settings lke the y-parameters, z-parameters and the h-parameters. Network analyzers are often used to characterize 2 or more ports networks like the amplifiers and filters parameters.

Network analyzers are often used at high frequencies, ranging from 9khz to 110Ghz. There are some special network analyzer that can also be used to measure frequency down to 1Hz, these analyzers can be used for stability analysis of open loops pr for the measurement of audio and ultrasonic components.

The main types of network analyzers are as followed:

  • Scalar Network Analyzer (SNA) — only used in measuring amplitude properties

  • Vector Network Analyzer (VNA) — measures both amplitude and phase properties. VNA can be also known as a gain phase meter or and Automatic network analyzer.

  • Microwave Transition Analyzer(MTA) &

  • Large Signal Network Analyzer(LSNA)--- both of them are used to measure both amplitude and phase of the fundamental harmonics. LSNA has an advantage over MTA due to its user friendly calibration features.

2.7 Agilent Advanced Design System

Advanced Design System is the leading software for designing automation RF, microwave and signal integrity applications. Because of its integrated design environments, ADS is commonly used by leading companies in designing products like the mobile phones, pagers, wireless networks, satellite communications, radar system and high speed data links.

Agilent ADS software is designed in the way that it supports almost every step of the design process, from schematic and layout design to simulation in both frequency and time domain thru the simulations. Allowing design engineers to optimize their design without have the trouble to change tools.

The following are some benefits of using Advanced design system:

  1. With the ADS circuit and electromagnetic simulator integrated into a common environment, the Agilent design flow offers the quickest path to a working design.

  2. ADS offers application specific design guides in an easy to use interface

  3. The software offers video library for users

  4. Tutorials are made easier with online tutorial videos in websites such as You Tube.

CHAPTER 3: PROJECT SELECTIONS

3.1 Selection of Substrate Material

Selection of substrate material is an important decision to make as it will not only affect the desired results from the product but also the size and dimension of the fabricated product. There are several parameters to be considered when selecting a suitable substrate material in the market. From the table below, we will take a look at some of the parameters in which how it will affect the overall selection.

Important factors

Criterions

Loss Tangent, Tan()

Known as the loss tangent, applicable in power and is impressed in percentage. To select a low Tanto have a lesser dielectric losses within capacitor

Dielectric constant

To have a high dielectric constant to allow more electric charge to be stored for a longer period

Thermal coefficient of the dielectric constant (TCE)

To have a low thermal coefficient of the dielectric constant, so as to minimise the amount of variations of the dielectric constant due to temperature change.

Thickness of Substrate

Allow a thin fabrication finishes

Cost

Lowest cost possible

Table 3.1: Factors to consider in the selection of substrate materials

As for this project, we will look at the parameters for LTCC and Fr-4 which will be used later.

Substrate

Tan()

TCE

ppm/K

Thickness

Relative Price

LTCC

0.0015

5.4

8

100

Very costly

FR4

2.7

4.7

18

1600

Relatively cheap

Table 3.2: List of substrate materials used in the project

3.2 Selection of Software Simulator Tool

In this topic, we are discussing software tool used to help us design and simulate the results.

Through the recommendation by the school, we decided to take the challenge of using ADS (Agilent Advanced Design System). The below shows some of the advantages of ADS compare to other software.

- Well establish in the markets, leading electronic design for high frequencies applications

- used by many companies in the wireless communication and network industries

- provides full, standards based design and verification with Wireless libraries and circuit system simulation in an integrated platform

- Tutorial and guide available in the website

- Easy to analysis with S-parameters

- Comes free will the trial period of 3 months

- Low resources consumption

3.3 Selection of Measuring Equipment – Network Analyzer

After the fabrication of our design, it is required to obtain the measured results and compared to the simulation results. This will thus tells us how far our results are away from the actual results.

By using the right measuring equipment to do the job is necessary. Due to the limitation of resources, we will have to use the Agilent Network Analyzer E5062A provided by our school laboratory.

Fig 3.1: Photo of Agilent Network Analyzer E5062A

Measurement Capabilities

Frequencies range

300Khz to 3GHz

Number of measurement channels

4 independent measurement channels

Number of display windows

Up to 4 display windows

Number of traces

4 data traces and 4 memory traces per channel

Accuracy

+/- 0.75dB

Measurement

Integrated T/R or S-parameter

Data formats

Log magnitude, linear magnitude, phase, expanded phase, positive phase, group delay, real, imaginary, Smith chart, polar, VSWR

Data markers

10 independent markers

Table 3.3: Measurement capabilities of E5062A

3.4 Selection of Balun Design Topology

Former design of balun was introduced by N.Marchand by using wideband Marchand balun to develop high frequency application such as balanced mixer and antenna feeding. By using co-planar strip lines where an extended ground plane is installed to insure the proper behaviour of this balun. But by using this method, it is reported that the broadside electromagnetic coupling tends be proven weak. Thus several investigations have been pursued to improve the design coupling coefficient.

-Vertical coupling proves a better suggestion compare to broadside coupling.

-Though LTCC balun has being used to provide better performance, it is only used in lower frequencies.

-with modification on Marchand balun, millimetre wave baluns have been reported but with high insertion losses.

Through the understand of microstip line and Coplanar strip line in the earlier chapter, the Balun design topology is determine to use a 3D multi-layer consist of microstrip line on the first layer followed by Coplanar Strip line (CPS) in the second layer. The option of adding the ground plane on the third layer depends on the performance of the design.

Our solution to these, we therefore approach using LTCC balun with multi-layer microstrips and CPS line embedded in low loss LTCC dielectrics.

Figure 3.2: 3D LTCC with multi-layers microstrips and CPS line

CHAPTER 4: FILTER DESIGN & SIMULATION USING LTCC

4.1 Initial Design of Balun using LTCC technology

LTCC has become popular in the recent years for its 3D multi-layer and high integration capability for passive devices. In this chapter, we look at the design of a LTCC Balun using multi-layer microstrip and coplanar strip lines embedded in this low loss LTCC dielectric.

4.1.1 Setting up ADS

Using ADS, the first step is to create the substrate layers and declaring parameters like its thickness, permittivity constant and its loss tangent illustrate in Fig 4.1a.

In Figure 4.1b, we strip the substrate layers and declare names to its layout layers. Each layout layer has a unique name and colour to enhance the clarity of the design. With thickness each of 100μm and insert via holes between layers when necessary.

Figure 4.1a – Creating substrates layers in ADS

Figure 4.1b – Declaration of layout layers

Just before we start on the design drawing, we need to understand our simulation parameters like the frequencies range, the numbers of sampling points and the sweep type shown in Figure 4.1c.

Figure 4.1c – Setting of Simulation parameters

4.1.2 Port parameter in ADS

By inserting input and output ports, we need to set the setting in the port editor to 50Ω so that we are able to installed 50Ω SMA connector after we have fabricated the design. The port type selected here is “Single”.

Figure 4.1d – Ports Properties parameters

4.1.3 Calculation of Micro-strip width using LineCal

LineCal is a built in function in ADS to allow user to have the ease of tedious calculation for the microstrip width and length. Thru LineCal, the designers just need to input parameters and followed by the Synthesize button to have the calculated results shown in the figure 4.3 below.

Parameters to input in LineCal

  • Dielectric Constant, εr = 5.4,

  • Height, H = 110.00 um,

  • Thickness, T = 27 um,

  • Characteristic Impedance, Z0 = 50Ω.

Figure 4.2 : LineCal function in ADS

With the help of LineCal we manage to get the width of the microstrip to be 163um and the length obtain here need to adjust according with center frequency of 35GHz, discuss later in Section 4.1.4

4.1.4 Obtaining Design Parameters

Determine the length of the top layer micro-strip open ended stub(yellow)

------------------------------ Eqn (2)

When our εr = 5.4,

Height, H = 110.00 um

and width calculated by LineCal to be w = 163um.

The calculated εre = 4.258 based of Eqn(1).

With εre the length of the microstrip can be now calculated based on Eqn(2) and Eqn(3),

---------------------------------------------Eqn(3)

λg = 3635 um.

------------------------------------------------------Eqn(4)

l = 1817.5um.

Determine the length/width/gap of CPS line

With the parameters of the CPS the same as in the microstrip, with Er = 5.4, Height = 110 um and Thickness = 27um, the gap and the width of the gap is designed to be 75um to obtain a characteristic impedance of 70Ω using LineCal function in ADS.

Figure 4.3 – CPS calculation on LineCal

Where the length of the CPS was set to a quarter guided wavelength to optimize the bandwidth performance.

l = λg / 4 ---------------------------------------------------Eqn(5)

Figure 4.4- Configuration of a CPS

-----------------------------------------------------------------Eqn(6)

k is calculated to be 0.33422 when the width and the gap of the CPS designed to be 70um.

-------------------------------------------------------------Eqn(7)

and k’ to be 0.7425.

--------------------------------------------------------Eqn(8)

k1 calculated to be 0.20095.

-----------------------------------------Eqn(9)

And from LineCal K was found to be 2.503, thus giving εeff of 1.997.

And we have Length of the CPS line to be 884.55um based on Eqn(3) and Eqn(5).

The initial design of the balun has an area of 2.1mm by 0.33mm which corresponds to 0.42λo and 0.066 λo respectively. Though the design will be optimize for best result in the later stage.

Determine the taper angle Ɵ1 and Ɵ2

To study the taper angle effects on the amplitude and phase between between the two CPS line branches. Table 4.1 shows some selected tangents values of the 2 angles Ɵ1 and Ɵ2.

Table 4.1 – Taper Angle Selections

By using MoM(Method of Moment) software, we have chosen condition 3 as the final design so that the amplitude imbalanced is within +/- 0.5 dB and phase difference is within +/- 1.25 degree at the design 40GHz specification.

4.1.5 Design Implementation – Designing and simulating the design using ADS

With all the design parameters on hand, the design is created using ADS in its LAYOUT function. The first layer consist of the microstrip when dimension of 1817.5um x 162um. The top layer will then be lying on top of the second layer consist of the CPS. The CoPlanar Strip is designed asymmetrically so that the output amplitude and phase of the balun will balance. Then second layer will then be connected to the third layer by the Via hole. This third layer is of a ground plane which has the parameters of Er = 1 while its thickness remain the same as the other layers. The input port and output port are placed asymmetrically on the top and bottom to achieve the balanced output.

Figure 4.5 – Overall design of a balanced LTCC Balun

4.1.6 Simulation Result of LTCC Balun with Modified Dimension

Figure 4.6a shows the return loss and insertion loss of the balanced back to back transition. The measured insertion loss is -4.334dB at 40 GHz. Thus each balun and a quarter guided wavelength CPS line have an insertion loss that can be estimated at 2.167dB.

The 10 dB return loss bandwidth is achieved from 26.04GHz to 55.63GHz (72.46% relative bandwidth centered at 40.835GHz).

Figure 4.6a –Return loss and Insertion loss results from a LTCC balanced back to

back transition

This result is obtained by modifying from the calculated dimension and thus getting the optimized results.

Figure 4.6b shows the return loss and insertion loss of the unbalanced back to back transition. The measured insertion loss is –3.025dB at 40 GHz. Thus each balun and a quarter guided wavelength CPS line have an insertion loss that can be estimated at -1.51dB.

The 10 dB return loss bandwidth is achieved from 24.58GHz to 55.65GHz (77.45% relative bandwidth centered at 40.115GHz).

Figure 4.6b – Results obtain from an unbalanced LTCC Balun

CHAPTER 5: Balun Design & Simulation Using FR-4

5.1 Initial Design of Balun using FR4

Due to the very high cost of fabricating the LTCC design and the constraints of resources, this project will be modified using FR4 instead for the fabrication. By doing so, the operating frequency need to be adjusted according. Therefore, the desired center frequency is adjusted to be 1.5GHz to suit our Network Analyzer operating frequencies. The substrate used here is FR4 with dielectric constant of 4.7 and has a loss tangent of 0.027 and thickness of 1600μm.

5.1.1 Setting up ADS

The first step to start this project of using FR4 is to set up the ADS software. Declarations of FR4 substrate parameters need to be completed first to kick start the design.

Firstly, to create a mulit-layers FR4 substrates that consist of fr4_01 and fr4_02 in which the extreme top and bottom layer is the free space with “OPEN” boundary and of εr=1. Inputs parameters have been set to fr4_01 and fr4_02 with thickness of 1600um, εr of 4.7 and loss tangent of 0.027. These creation of substrate layers can be found by selecting Momentum>Substrate>Create/Modify.

Figure 5.1a – Snap shot of the creation of mulit-layers FR4 substrates with its parameter

Followed by striping each substrate by naming the dielectric layer by a unique name and input its thickness to 17um. fr4_02 in this case is slot with a via hole to the ground plane where for this design, we called it the FreeSpace_lower.

Figure 5.1b –Snap shot of dielectric layer declaration

Through selecting Momentum>Simulation>S-Parameter, the setup of the design simulation is set from 0 GHz to 3 GHz with sample Points limit set to 9999 points.

Figure 5.1c- Software Simulation setup

5.1.2 Setting up port parameter in ADS

By inserting input and output ports, we need to set the setting in the port editor to 50Ω so that we are able to installed 50Ω SMA connector after we have fabricated the design. The port type selected here is “Single”.

Fig 5.1d: Snap shot of Port properties settings

5.1.3 Calculation of Micro-strip width using LineCal

LineCal is a built in function in ADS to allow user to have the ease of tedious calculation for the microstrip width and length. By using LineCal function, the designer just need to input parameters and followed by the Synthesize button to have the calculated results shown in the figure 4.3 below.

Parameters to input in LineCal

  • Dielectric Constant, εr = 4.7,

  • Height, H = 1600 um,

  • Thickness, T = 17 um,

  • Characteristic Impedance, Z0 = 50Ω.(prior for connecting the 50 Ω SMA connector after fabricating)

Figure 5.2-Calculation of MicroStrip using LineCal

With the help of LineCal we manage to get the width of the microstrip to be 2887.21um and the length obtain here need to adjust according with center frequency of 1.5GHz, discuss later in Section 5.1.4

5.1.4 Obtaining Design Parameters using ADS

Determine the length of the top layer micro-strip open ended stub(yellow)

With the help of LineCal, the results generated enable us to calculate the dielectric effective constant which will in term used in calculating the microstrip length.

For wide microstrip, W/h 1 :

------------------------------ Eqn (2)

With εr = 4.7,

Height, H = 1600.00 um

and width calculated by LineCal to be w = 2887.21um.

The calculated εre = 3.5189 based of Eqn(2).

With εre the length of the microstrip can be now calculated based on Eqn(2) and Eqn(3),

-------------------------------------------------------------Eqn(3)

λg = 106617.019 um.

---------------------------------------------------------------------Eqn(4)

l = 53308.51um.

Since ,

an increased in the center frequency will eventually has a decrease in the length of the microstrip.

Determine the length/width/gap of CPS line

With the parameters of the CPS the same as in the microstrip, with Er = 4.7, Height = 1600 um and Thickness = 17um, the gap and the width of the gap is designed to be 300um to obtain a characteristic impedance of 83.86Ω using LineCal function in ADS. This CPS output line substantially tends to have a characteristic impedance higher than 50Ω.

Figure 5.3 – CPS calculation on LineCal

Where the length of the CPS was set to a quarter guided wavelength to optimize the bandwidth performance.

l = λg / 4 --------------------------------------------------------------------------Eqn(5)

Figure 5.4- Configuration of a CPS

---------------------------------------------------------------------------Eqn(6)

k is calculated to be 0.3333 when the width and the gap of the CPS designed to be 300um.

------------------------------------------------------------------ Eqn(7)

and k’ calculated to be 0.9428.

-----------------------------------------------------------------Eqn(8)

k1 calculated to be 0.324.

------------------------------------------------Eqn(9)

And from LineCal K was found to be 2.75, thus giving εeff of 2.7922.

And we have Length of the CPS line found to be 14.96mm based on Eqn(3) and Eqn(5).

The initial design of the balun has an area of 42mm by 6.6mm which correspond to 0.42λo and 0.066 λo respectively. Although the design will be optimize for best result in the later stage.

Determine the taper angle Ɵ1 and Ɵ2

To study the taper angle effects on the amplitude and phase between between the two CPS line branches. Table 4.1 shows some selected tangents values of the 2 angles Ɵ1 and Ɵ2.

Table 4.1 – Taper Angle Selection

By using MoM(Method of Moment) software, we have chosen condition 3 as the final design so that the amplitude imbalanced is within +/- 0.5 dB and phase difference is within +/- 1.25 degree at the design 40GHz specification.

5.1.5 Design Implementation – Designing and simulating the design using ADS

With all the design parameters on hand, the design is created using ADS in its LAYOUT function. The first layer consists of the microstrip with dimension of 53308.5um x 2887.2um. The top layer will then be lying on top of the second layer consist of the CPS. The CoPlanar Strip is designed asymmetrically so that the output amplitude and phase of the balun will balance. The second layer will then be connected to the third layer by the Via hole. This third layer is of a ground plane which has the parameters of Er = 1 while its thickness remain the same as the other layers. The input port and output port are placed asymmetrically on the top and bottom to achieve the balanced output.

5.1.6 Simulation Result of FR4 Balun with Modified Dimension

Figure 5.6a shows the return loss and insertion loss of the balanced back to back transition. The measured insertion loss is -1.022dB at 1.5 GHz. Thus each FR4 balun and a quater guided wavelength CPS line have an insertion loss that can be estimated at -0.511dB.

The 10 dB return loss bandwidth is achieved from 1.344GHz to 1.828GHz (30.52% relative bandwidth centered at 1.586GHz).

Figure 5.5a –Return loss and Insertion loss results from a balanced back to back

transition

This result is obtained by modifying from the calculated dimension and thus getting the optimized results. With new dimension of (570μm x 6118μm) for the microstrip, 7345μm x 1157μm for the balun and 300μm for the gap and the width for the CPS.

Figure 5.6b shows the return loss and insertion loss of the balanced back to back transition. The measured insertion loss is -1.016dB at 1.5 GHz. Thus each FR4 balun and a quarter guided wavelength CPS line have an insertion loss that can be estimated at -0.508dB.

The 10 dB return loss bandwidth is achieved from 1.366GHz to 1.820GHz (28.5% relative bandwidth centered at 1.593GHz).

Figure 5.5b –Return loss and Insertion loss results from an unbalanced back to back

transition

CHAPTER 6: Preparation for Fabrication

6.1 Exporting Gerber Files for Fabrication

This chapter explain the steps taken in order to start exporting the Gerber files form ADS. Gerber files are generated by using function in ADS and are generally used for fabricating of the prototype. Gerber format are of a standard recognized by many PCB manufacturer as a form of CAD representation. Below are some steps to be taken before exporting Gerber file.

  1. Removal of input and output ports from the design as they are not relevant for the creation of Gerber files.

  2. Create individual rectangular borders for each layer of conductor , via hole and ground plane and connect a strip linking to the frame of the border for the position located on the input port and output port. This border act as markings for the fabrication.

  3. Setting up of Exporting Gerber Function

  4. Exporting Gerber files from ADS software.

The steps to export the gerber file are as followed:

  1. Under File, click on the Export function

Figure 6.1- Export function in ADS

  1. Under File Type, choose Gerber from the list and set the destination directory folder.

Figure 6.2- File destination directory folder.

  1. Under the More Option, check that the File Format selected is RX274X, Output Unit is in mm and take note at the file name of the Gerber is named.

Figure 6.3 – File Format/Output Unit

  1. Click on OK to start the export.

  2. When the Gerber file is successfully created, a pop out status will appear on screen.

Figure 6.4 - Snap shot of pop out when file is created

CHAPTER 7 : Project Summary

7.1 CONCLUSION

Based on the results obtained from Figure 4.6a and Figure 4.6b, the asymmetric structured LTCC balun can say to be successful in obtain a wideband balun operation with low insertion loss characteristic at millimetre wave. With its compact size, the balun is able to obtain a low insertion loss of -4.334dB (balanced) and -3.02dB (unbalanced) at a high wideband of 40GHz.

For the modified design, FR4 substrate has been used due to the high fabrication cost of the LTCC substrate. With different design parameters limitation of FR4, it is observed that the simulated result from the FR4 design can obtain a better insertion loss but having a lower percentage of the 10dB return loss bandwidth. Based on Figure 5.6a and Figure 5.6b, the modified design with using FR4 substrate give a excellent insertion loss of -1.022dB (balanced) and -1.016dB (unbalanced). However it is not able to give a high percentage of the 10dB relative bandwidth. The optimized dimension of the FR4 design also has a bigger size compare to the initial design.

Design

Insertion Loss

10dB Return Loss bandwidth

Fabrication Cost

Total Design Dimension

LTCC Balun

-3.02dB

77.45%

Very High

(2.21 x 2.1)mm

Based on 40 GHz

FR4 Balun

-1.016dB

30.5%

Low

(7.34 x 10.2)mm

Based on 5GHz

Table7.1 shows the results of the LTCC balun and FR4 balun

7.2 Problems and solutions

Problem 1 – Difficulties in drawing design dimension of up to 3 decimal points accuracy

in ADS software.

Solution – By selecting Options/Preferences in ADS and adjusting the grid snap of a smaller value according.

Problem 2 – Having doubt in drawing the taper angle of the CPS shown in Figure7.1

Figure 7.1 – Taper angle in CPS

Solution – There is no way a user can draw such a dimension. The only solution is to draw a rectangular block with the two triangle calculated with the tapered angle and placed them together and followed by using the function “Union Minus Intersection” under Edit/Merge. This function will merge the different shapes in a way that it minus off the smaller shape lapping shape of a bigger size.

Problem 3 – Unable to fabricate the FR4 balun due to vendor limitation.

According to the Sales Engineer from Precision Circuit Manufacturers Pte Ltd, the width and the slot in the Coplanar strip line are below their fabrication machines specification that required more than 300µm.

Figure 7.2 – Final design dimension

7.3 Suggestion for Future Work

Initial design with LTCC

Although this project achieved the aim of obtaining a loss insertion loss and compact size balun for millimetre wave using LTCC substrate, there are many areas which this project can be improved,

  1. Currently designed to operate at 40GHz, a improvise design can be considered to set the operating frequency higher. As technology grows with time, a search for a more compact design will soon be implemented.

  1. For this project, impedance transformation of 50Ω - 70Ω is set for the dimension between the microstrip and the coplanar strip. This is not good enough for integration such as of a high end input impedance antenna. To improve on this factor, the design dimension should be set such a way that the input port (microstrip) side has a 50Ω impedance characteristic and a high impedance characteristic of more than 100Ω at the output port.

  1. Based on Figure 4.6a and Figure 4.6b, the 10dB return loss bandwidth are achieved at 72.46% and 77.45% respectively for back to back balanced and unbalanced transition. To further improve on this result, the design configuration can be further modified to achieve a higher percentage.

  1. The most important improvement for the design is to achieve a better insertion loss in the result. The design need to be improved so as to get a result close to 0dB in the S21 parameter.

Design with FR4

  1. The dimension of the design is causing problem for local fabrication company. For simplicity seek, the design should have at least 300µm width or gap between any microstrip lines or coplanar strip lines.

  1. The 10dB return loss bandwidth of 30.52% and 28.5% for the balanced and unbalanced back to back transition is too low. The design should be modified to obtain a higher percentage.

REFERENCES

[1] K.Wantanabe, K. Nakayama and ui, “ An investigation of the properties of new-developed LTCC materials for their use in microwave circuit,” Proceedings of 2002 IMAPS, pg 389-393, Nov. 2002

[2] S. Watanabe, K. Nakayama and K. Watanabe, “An investigation of the properties of newly developed LTCC materials for their use in microwave antenna,” Proceedings of 2003 IMAPS, pp. 453-458, Nov. 2003

[3] N.Marchand, “ Transmission of line conversion transformers,” Electronics, vol 17, no. 12, pp 142-145, Dec 1944

[4] N. Michishita, H. Arai, M.Nakao, T.Satoh and T.Matsuoka,” FDTD analysis for printed dipole antenna with balun,” 2000 Asia Pacific Microwave Conference, pp 739-742, Dec 2000

[5] N. Michishita, H. Arai, K. Tsunekawa and M. Karikomi, “FDTD analysis of dual frequency printed dipole antenna,” 2002 IEEE Antennas and Propagation Society International Symposium, vol2 pp 40-43, Jun 2002

[6] C.Choonsik and K.C. Gupta,”A new design procedure for single layer and two layer three line baluns,” IEEE Trans. Microwave Theory and Tech., vol46, no. 12, pp 2514-2519, Dec 1998

[7] K.S Ang and I.D. Robertson,” Analysis and design of impedance-transforming planar Marchand Baluns,” IEEE Trans. Microwave Theory and Tech, vol. 49, no, pp 402-406, Feb, 2001

[8] C.W Tang and C.Y Chang,” A semi-lumped balun fabricated by low temperature co-fired ceramic,” 2002 IEEE MTT-S Int. Microwave Symposium Digest, vol3, pp. 2201-2204, Jun, 2002

[9] K.S Ang and I.D Robertson, “A analysis and design of impedance-transforming planar Marchand Baluns,” IEEE Trans. Microwave Theory and Tech, vol49, no.2, pp402-406, Feb, 2001

[10] K.Nishikawa, I. Toyoda and T.Tokumitsu, “ Compact and broad-band three dimensional MMIC Balun,” IEEE Trans. Microwave Theory and Tech, vol47, no.1,pp96-98, Jan, 1999

[11] J.L Chen,S F. Chang and B.Y Laue, “ A 20-40 GHz monolithic doubly balanced mixer using modified planar Marchand baluns,” 2001 Asia Pacific Microwave Conference, vol1, pp131-134, Dec 2001

[12] Jia-Sheng Hong, M.J. Lan Caster, “Microstrip Lines,” Microstrip Filters for RF/Microwave Applications, New York: John Wiley & Sons Inc, 2001

[13] Thomas L.Floyd, “Capacitors,” Principles Of Electric Circuits, New Jersey: Prentice-Hall Inc,1997

[14] J.Lakshmi Narayan, Dr. K Sri Rama Krishna and Dr. L Pratap Reddy, “ANN Models for Coplanar Strip Line Analysis and Synthesis,” IJCSNS International Journal of Computer Science and Network Security, Vol8 No.10, Oct, 208

[15] M. Nisenoff and W. J. Meyers (Editors), Special Issue on the Microwave and

Millimeter Wave Applications of High Temperature Superconductivity, IEEE

Trans. Microwave T heory Tech., Vol. 44, No. 7, Part II, July 1996.

[16] W. Chew, L. J. Bajuk, T. W. Cooley, M. C. Foote, B. D. Hunt, D. L. Rascoe, and

A. L. Riley, ‘‘High-T_ Superconductor Coplanar Waveguide Filter,’’ IEEE Electron.

Device Lett., Vol. 12, No. 5, pp. 197—199, May 1991.

APPENDIX A – Specification for Agilent Network

Analyser E5062A

APPENDIX A – Specification for Agilent Network

Analyser E5062A

APPENDIX A – Specification for Agilent Network

Analyser E5062A

APPENDIX B – Projects Meeting Logs

CAPSTONE Project Meeting Report 01

1

Date

01Aug 2010

2

Time

9:30am – 11:30am

3

Duration

2 hours

4

Venue

UniSIM HQ Rm4.25

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

Na

8

Minutes of current meeting

  1. Supervisor discuss on the project scope

  2. Highlight of the entire year project and expectation

  3. Advise on usage for ADS(Agilent Advanced Design System)

  4. Highlight on the first design of project

  5. Futures objectives on next meeting

9

Action items/ Targets to achieve in current stage

  1. To sent meeting log after every meet up

  2. To hand in project proposal by 06sept (if possible 28Aug).

  3. Enhance personal understanding of LTCC and Filter Design

  4. Familiarize on the usage of ADS

10

Other comment/Areas to improve

  1. Next meeting will be held on 07Aug at RM 3.17

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

  3. K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 02

1

Date

15Aug 2010

2

Time

4:00pm – 06:00pm

3

Duration

2 hours

4

Venue

Blk 82 Rm2.02

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

More reading up to enhance understanding

8

Minutes of current meeting

-Supervisor demonstration on ADS on schematic and momentum platform

- Understand the modeling approach of LTCC filter using ADS

9

Action items/ Targets to achieve in current stage

-More reading up to understand project needs

-Commence handling LTCC filter modeling

-Commence on proposal read up

10

Other comment/Areas to improve

-Next meeting will be held on 21Aug, venue to be confirmed

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

  3. K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 03

1

Date

21Aug 2010

2

Time

03.00pm – 17:30am

3

Duration

2 hours

4

Venue

Block 82 #02-02

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

  1. Understanding the modeling approach of the LTCC using ADS

8

Minutes of current meeting

  1. Technical discussion of Balun design implementation

  2. Further discussion on the usage of ADS momentum platform for Balun design

9

Action items/ Targets to achieve in current stage

-To sent meeting log after 21Aug2010

-Presentation of the first design prototype design and simulation results

10

Other comment/Areas to improve

-Next meeting will be held on 04Sept

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 04

1

Date

04Sept 2010

2

Time

3.00pm – 5.00pm

3

Duration

2 hours

4

Venue

Block 82 #02-02

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

  1. Technical discussion of Balun design

implementation

  1. Further discussion on the usage of ADS momentum platform for Balun design

8

Minutes of current meeting

  1. Technical discussion on Balun Design

  2. Troubleshooting of layout momentum design problems

9

Action items/ Targets to achieve in current stage

  1. To sent meeting log after 21Aug2010

  2. Submission of meeting Log after the .

meeting and proposal.

10

Other comment/Areas to improve

  1. Next meeting will be held on 18Sept, 3pm-5pm

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

  3. K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 05

1

Date

18Sept 2010

2

Time

3.00pm – 5.00pm

3

Duration

2 hours

4

Venue

HQ RM04-23

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

  1. Discussion on problems faced on Balun design implementation

  2. Troubleshooting of layout momentum design problems

8

Minutes of current meeting

  1. Technical discussion and problem solving for Balun Design

  2. Analysis on current Balun performance

9

Action items/ Targets to achieve in current stage

  1. To sent meeting log after 18Sept2010

  2. Presentation of improved Balun performance

  3. Presenting more understanding of multi layer design

10

Other comment/Areas to improve

  1. Next meeting will be held on 16 OCT, 3pm-5pm

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

  3. K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 06

1

Date

16Oct 2010

2

Time

3.00pm – 5.00pm

3

Duration

2 hours

4

Venue

BLK 82 #03-11

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

  1. Discussion on problems faced on Balun design implementation

  2. Troubleshooting of layout momentum design problems

8

Minutes of current meeting

  1. Technical discussion and problem solving for Balun Design

  2. Analysis on current Balun performance

9

Action items/ Targets to achieve in current stage

  1. To sent meeting log after 18Sept2010

  2. Presentation of improved Balun performance

  3. Presenting more understanding of multi layer design

  4. Interim Report to be submitted on 08Nov

10

Other comment/Areas to improve

  1. Next meeting will be held on Jan 2011

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

  3. K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 07

1

Date

8Dec 2010

2

Time

8.00pm – 9.30pm

3

Duration

1.5 hours

4

Venue

Tampines

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

  1. Discussion on problems faced on Balun design implementation

  2. Troubleshooting of layout momentum design problems

8

Minutes of current meeting

  1. Technical discussion and problem solving for Balun Design

  2. Analysis on current Balun performance

9

Action items/ Targets to achieve in current stage

  1. To sent meeting log after 8Dec2010

  2. Presentation of improved Balun performance

  3. Improvise the design

10

Other comment/Areas to improve

  1. Next meeting will be held on Jan2011, to be confirmed

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 08

1

Date

12 Feb 2011

2

Time

10.00am – 12.00pm

3

Duration

2 hours

4

Venue

HQ Lab 5.17B

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

  1. Technical discussion and problem solving for Balun Design

  2. Analysis on current Balun performance

8

Minutes of current meeting

  1. Technical discussion of improvement of balun design

  2. Demonstration of fabrication process required for ADS

9

Action items/ Targets to achieve in current stage

  1. To sent meeting log after 12 Feb 2011

  2. Final improvement of design

  3. Preparation for fabrication

10

Other comment/Areas to improve

  1. Next meeting will be held on 26Feb2011, 10-12pm

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

  3. K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 09

1

Date

26 Feb 2011

2

Time

10am- 12pm

3

Duration

2 hours

4

Venue

HQ Lab 5.17b

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

  1. Technical discussion of improvement of balun design

  2. Demonstration of fabrication process required for ADS

8

Minutes of current meeting

  1. Final verification of gerber files on fabrication

  2. Final verificationof Balun performance

9

Action items/ Targets to achieve in current stage

  1. Presentation of Balun design concept

  2. Presenting on fabrication process

  3. Reminder on the date for submission of final year report(16May)

10

Other comment/Areas to improve

  1. Next meeting will be held on 12 Mar 2011

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

  3. K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

CAPSTONE Project Meeting Report 10

1

Date

30Apr 2011

2

Time

12pm- 2pm

3

Duration

2 hours

4

Venue

BLK 82 5.02

5

Student Name

Goh Jianming

6

Project / Supervisor Name

Compact Multilayer Broadband Balun Structure for Multilayer Wave(MM-V)Application/ Dr Lum Kum Meng

7

Review of Previous Meeting and progress

  1. Technical discussion of the simulated result

  2. Demonstration of fabrication process required for ADS

8

Minutes of current meeting

  1. Final verification of gerber files on fabrication

  2. Final verificationof Balun performance

9

Action items/ Targets to achieve in current stage

  1. Presentation of Balun design concept

  2. Presenting on fabrication process

  3. Reminder on the date for submission of final year report(16May)

10

Other comment/Areas to improve

  1. Improve the way of presenting the results

11

Reference materials

  1. K.Watanabe, K. Nakayama and ui, “An investigation of the properties of new developed LTCC materials for their uses in microwave circuits.

  2. Y.Qianand T.Itoh, “ A broadband uniplanar Marchand baluns”

  3. K.S And and I.DRobertson, “ A mm wave monolithic sub-harmonically pumped resistive mixer.

APPENDIX C – Simulated Results For LTCC Calculated

Dimension

Calculated Designs using LTCC

Design 1

Initial design with calculated dimension

APPENDIX D - Simulated Results For FR4 Calculated

Dimension

Calculated Designs using FR4

Design 1

Initial design with calculated demension

1

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