Sevick's Transmission Line Transformers: Theory And Practice (electromagnetics And Radar) (hardcover)

The long awaited revision of the classic book Transmission Line Transformers (2001) by Jerry Sevick has been updated and reorganised by Raymond Mack to provide communication engineers with a clear technical presentation of both the theory and practical applications of the transmission of radio communication. Sevick's Transmission Line Transformers: Theory and Practice, 5th edition reviews the underlying principles that promote a better understanding of transmission line transformers. Featuring expanded coverage, this book provides substantial background theory and includes recent work on fractional ratio transformers and high power Balun designs. Ideal for academics and practicing engineers, this edition is divided into two clear parts. Part one is a review of the theory and new concepts, including a discussion on the magnetic materials. Part two essentially focuses on the “practice” element of the book title and details the practical implications of transformers. Key features include: - Completely reorganised and logically indexed - Clear graphical presentation of transmission lines - Increased amount of background theory - Divided into two main parts for easy reference - Covers recent work on fractional ratio transformers and high power Balun designs Sevick's Transmission Line Transformers: Theory and Practice, 5th edition is a classic practitioner reference, ideal for communication engineers, undergraduate/graduate level students, radio hobbyists and professionals alike. Sevick’s Transmission Line Transformers: Theory and Practice, 5th Edition 4 Contents 8 Preface to the 5th Edition 12 In Memoriam 14 1 Transformer Basics 16 1.1 Introduction 16 1.2 The Basic Building Block 19 1.2.1 Phase Inverter 20 1.2.2 Balun 20 1.2.3 Delay Line 20 1.2.4 Bootstrap 21 1.3 Designing a Magnetic Transformer 21 References 23 2 Ferrite Materials 26 2.1 Introduction 26 2.2 Ferrite Physical Properties 27 2.3 Ferrite Permeability 28 2.4 Magnetic Losses 31 2.5 Ferrites and Frequency Response 33 2.6 Power Ratings 34 2.7 Suppliers of Materials 40 2.8 Additional Reading 40 References 40 3 Guanella Analysis 42 3.1 Introduction 42 3.2 Mid-Band Operation 42 3.3 Low Frequency Operation 45 3.4 Guanella Transformer Variations 47 4 Ruthroff Analysis 50 4.1 Introduction 50 4.2 Low Frequency Analyses of Ruthroff’s 1:4 Transformers 54 4.3 High Frequency Characterization 56 Reference 57 5 Transmission Line Construction 58 5.1 Introduction 58 5.2 Commercial Transmission Lines 58 5.3 Custom Coaxial Transmission Lines 58 5.4 Custom Parallel Transmission Lines 60 5.5 Closely Wound Twin Lead 65 5.6 Three Conductor Lines 66 5.7 Custom Multiconductor Transmission Lines 69 5.8 Comparison of Twisted Pair and Twin Lead 70 5.9 Long Transmission Lines 73 5.10 Variable Characteristic Impedance Lines 73 References 74 6 1:4 Unun Transformer Designs 76 6.1 Introduction 76 6.2 Schematics and Pictorials 77 6.3 12.5:50 Ω Ununs 79 6.4 25:100, 50:200, and 75:300 Ω Ununs 84 7 Unun Transformer Designs with Impedance Ratios Less Than 1:4 88 7.1 Introduction 88 7.2 1:1.5 Ununs 90 7.2.1 Tapped Bifilar Transformers 91 7.2.2 Quintufilar Transformers 94 7.3 1:2 Ununs 100 7.4 1:3 Ununs 111 8 Unun Transformer Designs with Impedance Ratios Greater Than 1:4 114 8.1 Introduction 114 8.2 Guanella Transformers 115 8.2.1 5.56:50 Ω Ununs 117 8.2.2 50:300 Ω Ununs 118 8.2.3 50:450 Ununs 119 8.2.4 50:600 Ω Ununs 119 8.2.5 50:800 Ω Ununs 122 8.3 Ruthroff-Type Transformers 122 8.3.1 5.56:50 Ω Ununs 126 8.3.2 50:450 Ω Ununs 128 8.3.3 3.125:50 Ω Ununs 129 8.4 Ruthroff-Guanella Transformers 131 8.5 Coax Cable Transformers—Ruthroff Type 132 Reference 134 9 Baluns 136 9.1 Introduction 136 9.2 The 1:1 Balun 136 9.2.1 Rod versus Toroidal Baluns 141 9.2.2 Bifilar versus Trifilar Baluns 142 9.2.3 Air Core versus Ferrite Core Baluns 144 9.3 The 1:4 Balun 144 9.3.1 50:200 Ω Baluns 148 9.3.2 75:300 Ω Baluns 151 9.3.3 25:100 Ω Baluns 152 9.3.4 12.5:50 Ω Baluns 153 9.4 The 1:9 Balun 154 9.5 Baluns for Yagi, Quad and Rhombic Antennas 157 9.5.1 Yagi Beams 157 9.5.2 Quad Antennas 158 9.5.3 Rhombic Antennas 159 10 Multimatch Transformers 162 10.1 Introduction 162 10.2 Dual-Output Transformers 163 10.2.1 1:1.5 and 1.3 Ratios 163 10.2.2 1:2 and 1:4 Ratios 166 10.3 Parallel Transformers 168 10.4 Eight-Ratio Transformer 170 11 Equal Delay Transformers 172 11.1 Introduction 172 11.2 The Need for Fractional Ratio Transformers 172 11.3 The Equal Delay Transformer 173 11.4 Integer [n2] Ratio Equal Delay Transformers 175 11.5 Fractional [(n/m)2] Ratio Equal Delay Transformers 176 11.6 Unun versus Balun Equal Delay Transformers 177 11.7 Calculation of Impedance Transformation Ratios 178 11.8 Achievable Transformation Ratios 180 11.9 A 50–75 Ω Equal Delay Unun Example 183 11.10 Performance of the 50–75 Ω Transformer 185 References 187 12 Simple Test Equipment 188 12.1 Introduction 188 12.2 Transformer Impedance Measurement 188 12.3 Transmission Line Impedance Measurement 189 12.4 Home-Built Equipment 192 12.5 The Wheatstone Bridge 193 12.6 A High-Frequency Resistive Bridge 194 12.7 Signal Generators 197 12.8 Efficiency Measurements—The Soak Test 199 12.9 Characteristic Impedance Measurements 200 References 202 13 Construction Techniques 204 13.1 Introduction 204 13.2 Selecting Ferrites—Substitutions 204 13.3 Winding Rod Transformers 205 13.4 Winding Toroidal Transformers 206 13.5 Constructing Low Impedance Coax Cable 207 13.6 The Care and Handling of Ferrite Transformers 209 Appendix A: Reprint of Guanella Article 210 Appendix B: Some Broad-Band Transformers 216 Polarity Reversing Transformer-Figure 1 218 Balanced-To-Unbalanced 1:1 Impedance Transformer-Figure 2 220 Unbalanced-Unsymmetrical 4:1 Impedance Transformer-Figure 3 220 Unbalanced-Symmetrical 4:1 Impedance Transformer—Figure 4 224 Balanced-To-Unbalanced 4:1 Impedance Transformers–Figure 5 225 Hybrid Circults: Figures 6-9 225 Applications 226 Appendix A 227 Appendix B 229 Acknowledgement 230 References 230 Index 232 1 Transformer Basics 1 1.1 Introduction 1 1.2 The Basic Building Block 4 1.2.1 Phase Inverter 5 1.2.2 Balun 5 1.2.3 Delay Line 5 1.2.4 Bootstrap 6 1.3 Designing a Magnetic Transformer 6 References 8 2 Ferrite Materials 11 2.1 Introduction 11 2.2 Ferrite Physical Properties 12 2.3 Ferrite Permeability 13 2.4 Magnetic Losses 16 2.5 Ferrites and Frequency Response 18 2.6 Power Ratings 19 2.7 Suppliers of Materials 25 2.8 Additional Reading 25 References 25 3 Guanella Analysis 27 3.1 Introduction 27 3.2 Mid-Band Operation 27 3.3 Low Frequency Operation 30 3.4 Guanella Transformer Variations 32 4 Ruthroff Analysis 35 4.1 Introduction 35 4.2 Low Frequency Analyses of Ruthroff’s 1:4 Transformers 39 4.3 High Frequency Characterization 41 Reference 42 5 Transmission Line Construction 43 5.1 Introduction 43 5.2 Commercial Transmission Lines 43 5.3 Custom Coaxial Transmission Lines 43 5.4 Custom Parallel Transmission Lines 45 5.5 Closely Wound Twin Lead 50 5.6 Three Conductor Lines 51 5.7 Custom Multiconductor Transmission Lines 54 5.8 Comparison of Twisted Pair and Twin Lead 55 5.9 Long Transmission Lines 58 5.10 Variable Characteristic Impedance Lines 58 References 59 6 1:4 Unun Transformer Designs 61 6.1 Introduction 61 6.2 Schematics and Pictorials 62 6.3 12.5:50 W Ununs 64 6.4 25:100, 50:200, and 75:300 W Ununs 69 7 Unun Transformer Designs with Impedance Ratios Less Than 1:4 73 7.1 Introduction 73 7.2 1:1.5 Ununs 75 7.2.1 Tapped Bifilar Transformers 76 7.2.2 Quintufilar Transformers 79 7.3 1:2 Ununs 85 7.4 1:3 Ununs 96 8 Unun Transformer Designs with Impedance Ratios Greater Than 1:4 99 8.1 Introduction 99 8.2 Guanella Transformers 100 8.2.1 5.56:50 W Ununs 102 8.2.2 50:300 W Ununs 103 8.2.3 50:450 Ununs 104 8.2.4 50:600 W Ununs 104 8.2.5 50:800 W Ununs 107 8.3 Ruthroff-Type Transformers 107 8.3.1 5.56:50 W Ununs 111 8.3.2 50:450 W Ununs 113 8.3.3 3.125:50 W Ununs 114 8.4 Ruthroff-Guanella Transformers 116 8.5 Coax Cable Transformers—Ruthroff Type 117 Reference 119 9 Baluns 121 9.1 Introduction 121 9.2 The 1:1 Balun 121 9.2.1 Rod versus Toroidal Baluns 126 9.2.2 Bifilar versus Trifilar Baluns 127 9.2.3 Air Core versus Ferrite Core Baluns 129 9.3 The 1:4 Balun 129 9.3.1 50:200 W Baluns 133 9.3.2 75:300 W Baluns 136 9.3.3 25:100 W Baluns 137 9.3.4 12.5:50 W Baluns 138 9.4 The 1:9 Balun 139 9.5 Baluns for Yagi, Quad and Rhombic Antennas 142 9.5.1 Yagi Beams 142 9.5.2 Quad Antennas 143 9.5.3 Rhombic Antennas 144 10 Multimatch Transformers 147 10.1 Introduction 147 10.2 Dual-Output Transformers 148 10.2.1 1:1.5 and 1.3 Ratios 148 10.2.2 1:2 and 1:4 Ratios 151 10.3 Parallel Transformers 153 10.4 Eight-Ratio Transformer 155 11 Equal Delay Transformers 157 11.1 Introduction 157 11.2 The Need for Fractional Ratio Transformers 157 11.3 The Equal Delay Transformer 158 11.4 Integer [n2] Ratio Equal Delay Transformers 160 11.5 Fractional [(n/m)2] Ratio Equal Delay Transformers 161 11.6 Unun versus Balun Equal Delay Transformers 162 11.7 Calculation of Impedance Transformation Ratios 163 11.8 Achievable Transformation Ratios 165 11.9 A 50–75 W Equal Delay Unun Example 168 11.10 Performance of the 50–75 W Transformer 170 References 172 12 Simple Test Equipment 173 12.1 Introduction 173 12.2 Transformer Impedance Measurement 173 12.3 Transmission Line Impedance Measurement 174 12.4 Home-Built Equipment 177 12.5 The Wheatstone Bridge 178 12.6 A High-Frequency Resistive Bridge 179 12.7 Signal Generators 182 12.8 Efficiency Measurements—The Soak Test 184 12.9 Characteristic Impedance Measurements 185 References 187 13 Construction Techniques 189 13.1 Introduction 189 13.2 Selecting Ferrites—Substitutions 189 13.3 Winding Rod Transformers 190 13.4 Winding Toroidal Transformers 191 13.5 Constructing Low Impedance Coax Cable 192 13.6 The Care and Handling of Ferrite Transformers 194 Appendix A Reprint of Guanella Article 195 Appendix B Some Broad-Band Transformers 201

The long awaited revision of the classic book Transmission Line Transformers, by Jerry Sevick, is now in its fifth edition and has been updated and reorganised by Raymond Mack to provide communication engineers with a clear technical presentation of both the theory and practical applications of the transmission of radio communication.

Sevick's Transmission Line Transformers: Theory and Practice, 5th Edition reviews the underlying principles that promote a better understanding of transmission line transformers. Ideal for academics and practicing engineers, this edition is divided into two clear parts for easy reference. Part one is a review of the theory and new concepts, including a discussion on the magnetic properties that affect the core of a transmission line transformer. Part two essentially focuses on the 'practice' element of the book title. This section has been updated to reflect the significant changes in component suppliers over the 30 years since the first edition of the book.

Highlights of this title include the coverage of substantial background theory, recent work on fractional ratio transformers and high power Balun designs, and provides updated sources for transformer materials to reflect mergers, sales, and business failures over the past 20 years. There is also expanded coverage of commercial sources of low impedance coaxial cable; expanded construction hints for purpose built rectangular parallel transmission lines; plus an updated test equipment chapter to reflect modern computer based experimenter grade test equipment sources. Ray has leveraged his experience with ferrite materials for switching power to explain the performance characteristics of the ferrite materials used for RF power transmission line transformers.

The long awaited revision of the classic book Transmission Line Transformers , by Jerry Sevick, is now in its fifth edition and has been updated and reorganised by Raymond Mack to provide communication engineers with a clear technical presentation of both the theory and practical applications of the transmission of radio communication. Sevick's Transmission Line Transformers: Theory and Practice, 5th Edition reviews the underlying principles that promote a better understanding of transmission line transformers. Ideal for academics and practicing engineers, this edition is divided into two clear parts for easy reference. Part one is a review of the theory and new concepts, including a discussion on the magnetic properties that affect the core of a transmission line transformer. Part two essentially focuses on the 'practice' element of the book title. This section has been updated to reflect the significant changes in component suppliers over the 30 years since the first edition of the book. Highlights of this title include the coverage of substantial background theory, recent work on fractional ratio transformers and high power Balun designs, and provides updated sources for transformer materials to reflect mergers, sales, and business failures over the past 20 years. There is also expanded coverage of commercial sources of low impedance coaxial cable; expanded construction hints for purpose built rectangular parallel transmission lines; plus an updated test equipment chapter to reflect modern computer based experimenter grade test equipment sources. Ray has leveraged his experience with ferrite materials for switching power to explain the performance characteristics of the ferrite materials used for RF power transmission line transformers. The long awaited revision of the classic book Transmission Line Transformers, by Jerry Sevick, is now in its 5th edition and has been updated and reorganised by Raymond Mack to provide communication engineers with a clear technical presentation of both the theory and practical applications of the transmission of radio communication. The book has thirteen chapters. The topics covered are: transformer basics; ferrite materials; Guanella analysis; Ruthroff analysis; transmission line construction; unun transformer designs; baluns; multimatch transformer; equal delay transformer; simple test equipment; and construction technique