Table of Contents

Preface xxiii

Acknowledgements xxv

1 Introduction to Design Using Microstrip and Planar Lines 1

1.1 Introduction 1

1.2 Origins of Microstrip 2

1.3 RF and Microwave Modules 4

1.4 Interconnections on RF and Microwave Integrated Circuits 13

1.5 High-speed Digital Interconnections 15

1.6 Summary 18

References 18

2 Fundamentals of Signal Transmission on Interconnects 19

2.1 Introduction 19

2.2 Transmission Lines and Interconnects 19

2.3 Interconnects as Part of a Packaging Hierarchy 20

2.4 The Physical Basis of Interconnects 21

2.5 The Physics, a Guided Wave 23

2.6 When an Interconnect Should be Treated as a Transmission Line 32

2.7 The Concept of RF Transmission Lines 34

2.8 Primary Transmission Line Constants 34

2.9 Secondary Constants for Transmission Lines 35

2.10 Transmission Line Impedances 37

2.11 Reflection 38

2.12 Multiple Conductors 41

2.13 Return Currents 44

2.14 Modeling of Interconnects 47

2.15 Summary 49

References 50

3 Microwave Network Analysis 51

3.1 Introduction 51

3.2 Two-port Networks 51

3.3 Scattering Parameter Theory 55

3.4 Signal-flow Graph Techniques and S Parameters 70

3.5 Summary 74

References 74

4 Transmission Line Theory 76

4.1 Introduction 76

4.2 Transmission Line Theory 76

4.3 Chain (ABCD) Parameters for a Uniform Length of Loss-free Transmission Line 81

4.4 Change in Reference Plane 82

4.5 Working With a Complex Characteristic Impedance 83

4.6 Summary 87

References 88

5 Planar Interconnect Technologies 89

5.1 Introductory Remarks 89

5.2 Microwave Frequencies and Applications 89

5.3 Transmission Line Structures 91

5.4 Substrates for Planar Transmission Lines 98

5.5 Thin-film Modules 102

5.6 Thick-film Modules 104

5.7 Monolithic Technology 105

5.8 Printed Circuit Boards 108

5.9 Multichip Modules 111

5.10 Summary 116

References 117

6 Microstrip Design at Low Frequencies 120

6.1 The Microstrip Design Problem 120

6.2 The Quasi-TEM Mode of Propagation 122

6.3 Static-TEM Parameters 124

6.4 Effective Permittivity and Characteristic Impedance of Microstrip 127

6.5 Filling Factor 132

6.6 Approximate Graphically Based Synthesis 134

6.7 Formulas for Accurate Static-TEM Design Calculations 137

6.8 Electromagnetic Analysis-based Techniques 139

6.9 A Worked Example of Static-TEM Synthesis 140

6.10 Microstrip on a Dielectrically Anisotropic Substrate 141

6.11 Microstrip and Magnetic Materials 146

6.12 Effects of Finite Strip Thickness, Metallic Enclosure, and Manufacturing Tolerances 147

6.13 Pulse Propagation along Microstrip Lines 151

6.14 Recommendations Relating to the Static-TEM Approaches 152

6.15 Summary 154

References 155

7 Microstrip at High Frequencies 157

7.1 Introduction 157

7.2 Frequency-dependent Effects 157

7.3 Approximate Calculations Accounting for Dispersion 169

7.4 Accurate Design Formulas 173

7.5 Effects due to Ferrite and to Dielectrically Anisotropic Substrates 182

7.6 Field Solutions 183

7.7 Frequency Dependence of Microstrip Characteristic Impedance 186

7.8 Multimoding and Limitations on Operating Frequency 190

7.9 Design Recommendations 194

7.10 Summary 196

References 196

8 Loss and Power-dependent Effects in Microstrip 200

8.1 Introduction 200

8.2 Q Factor as a Measure of Loss 200

8.3 Power Losses and Parasitic Effects 208

8.4 Superconducting Microstrip Lines 216

8.5 Power-handling Capabilities 219

8.6 Passive Intermodulation Distortion 221

8.7 Summary 224

References 224

9 Discontinuities in Microstrip 227

9.1 Introduction 227

9.2 The Main Discontinuities 228

9.3 Bends in Microstrip 236

9.4 Step Changes in Width (Impedance Step) 241

9.5 The Narrow Transverse Slit 243

9.6 Microstrip Junctions 245

9.7 Recommendations for the Calculation of Discontinuities 261

9.8 Summary 266

References 266

10 Parallel-coupled Microstrip Lines 268

10.1 Introduction 268

10.2 Coupled Transmission Line Theory 269

10.3 Formulas for Characteristic Impedance of Coupled Lines 278

10.4 Semi-empirical Analysis Formulas as a Design Aid 290

10.5 An Approximate Synthesis Technique 301

10.6 Summary 304

References 304

11 Applications of Parallel-coupled Microstrip Lines 306

11.1 Introduction 306

11.2 Directional Couplers 306

11.3 Design Example: Design of a 10 dB Microstrip Coupler 308

11.4 Frequency- and Length-Dependent Characteristics of Directional Couplers 310

11.5 Special Coupler Designs with Improved Performance 315

11.6 Thickness Effects, Power Losses, and Fabrication Tolerances 329

11.7 Choice of Structure and Design Recommendations 331

11.8 Summary 336

References 337

12 Microstrip Passive Elements 339

12.1 Introduction 339

12.2 Lumped Elements 339

12.3 Terminations and Attenuators 343

12.4 Microstrip Stubs 345

12.5 Hybrids and Couplers 348

12.6 Power Combiners and Dividers 355

12.7 Baluns 357

12.8 Integrated Components 359

12.9 Summary 365

References 365

13 Stripline Design 369

13.1 Introduction 369

13.2 Symmetrical Stripline 370

13.3 Asymmetrical Stripline 373

13.4 Suspended Stripline 375

13.5 Coupled Stripline 375

13.6 Double-sided Stripline 379

13.7 Discontinuities 380

13.8 Design Recommendations 381

13.9 Summary 382

References 382

14 CPW Design Fundamentals 384

14.1 Introduction to Properties of Coplanar Waveguide 384

14.2 Modeling CPWs 389

14.3 Formulas for Accurate Calculations 391

14.4 Loss Mechanisms 393

14.5 Dispersion 397

14.6 Discontinuities 408

14.7 Circuit Elements 421

14.8 Variants on the Basic CPW Structure 430

14.9 Summary 439

References 439

15 Slotline 443

15.1 Introduction 443

15.2 Basic Concept and Structure 444

15.3 Operating Principles and Modes 444

15.4 Propagation and Dispersion Characteristics 447

15.5 Evaluation of Guide Wavelength and Characteristic Impedance 451

15.6 Losses 453

15.7 End-effects: Open Circuits and Short Circuits 455

15.8 Summary 463

References 463

16 Slotline Applications 465

16.1 Introduction 465

16.2 Comparators and Couplers 465

16.3 Filter Applications 472

16.4 Magic T 474

16.5 The Marchand Balun 477

16.6 Phase Shifters 480

16.7 Isolators and Circulators 481

16.8 A Double-sided, Balanced Microwave Circuit 486

16.9 Summary 486

References 486

17 Transitions 488

17.1 Introduction 488

17.2 Coaxial-to-microstrip Transitions 488

17.3 Waveguide-to-microstrip Transitions 490

17.4 Transitions between CPW and other Mediums 495

17.5 Slotline Transitions 498

17.6 Other Microstrip Transitions 510

17.7 Summary 511

References 511

18 Measurements of Planar Transmission Line Structures 514

18.1 Introduction 514

18.2 Instrumentation Systems for Microstrip Measurements 514

18.3 Measurement of Scattering Parameters 515

18.4 Measurement of Substrate Properties 519

18.5 Microstrip Resonator Methods 523

18.6 Q Factor Measurements 533

18.7 Measurements of Parallel-coupled Microstrips 535

18.8 Time-domain Reflectometry Techniques 537

18.9 Summary 539

References 539

19 Filters Using Planar Transmission Lines 541

19.1 Introduction 541

19.2 Filter Prototypes 541

19.3 Microstrip Filters 554

19.4 Microstrip Bandpass Filters 559

19.5 Parallel-coupled Line Bandpass Filters 561

19.6 Filter Design Accounting for Losses 572

19.7 Dielectric Resonators and Filters Using Them 572

19.8 Spurline Bandstop Filters 573

19.9 Summary 575

References 575

20 Magnetic Materials and Planar Transmission Lines 576

20.1 Introduction 576

20.2 Microwave Magnetic Materials 577

20.3 Effective Permeability of Magnetic Materials 587

20.4 Microstrip on a Ferrite Substrate 589

20.5 Isolators and Circulators 592

20.6 Transmission Lines Using Metaconductors 595

20.7 Frequency Selective Limiter 606

20.8 Summary 607

References 607

21 Interconnects for Digital Systems 610

21.1 Introduction 610

21.2 Overview of On-chip Interconnects 610

21.3 RC Modeling of On-chip Interconnects 613

21.4 Modeling Inductance 619

21.5 Clock Distribution 622

21.6 Resonant Clock Distribution 625

21.7 Summary 626

References 627

A Physical and Mathematical Properties 629

A.1 SI Units 629

A.2 SI Prefixes 629

A.3 Physical and Mathematical Constants 631

A. 4 Basis of Electromagnetic SI Units 631

A.5 Relationship of SI Units to CGS Units 632

B Material Properties 635

References 642

C RF and Microwave Substrates 643

C.1 Hard substrates 643

C.2 Soft Substrates 644

Index 647 

About the Author

Mr Terence Edwards,  Engalco Research, UK
Terry Edwards gained a Diploma in Technology (Eng.) at what is now London South Bank University. During his early career he was a senior development engineer for Ultra Electronics. This carried the responsibility for the microminiaturisation of electronics on the control system for the Concorde jet engine. Technology has been a constant theme for his career and he moved into lecturing basic electrical engineering and electronics at High Wycombe College of Technology & Arts. He took on a landmark role of senior lecturer at La Trobe University in Melbourne, Australia that involved him launching and teaching solid state microwave technology. Until recently he was Executive Director of Engalco Research, a strategic commercial and military industrial consultancy and research organization. Engalco is well known for providing industry and market data reports in the field of microwave products for defense and SATCOM applications. From January 2014 Terry has been leading a new management and technology venture names Edwards Research Associates.

Professor Michael B Steer, North Carolina State University, USA
Michael Steer is the Lampe Distinguished Professor of Electrical and Computer Engineering at North Carolina State University (NC State). He is a Fellow of the IEEE (the Institute of Electrical and Electronics Engineers). He was Secretary of the IEEE Microwave Theory and Techniques Society (MTT-S) in 1997 and was a member of the MTT-S Administrative Committee from 1998 to 2001, and from 2003 to 2006. He received a Service Recognition Awards from the Society in 1998 and 2001.