Table of Contents
Acknowledgments 9
1 Introduction 11
1.1 Helical Resonator Filters 12
1.2 Aim and Contents of This Book 14
References 16
2 Microwave Filters for Satellite Systems: Requirements and Constraints 19
2.1 Introduction 19
2.2 System Perspective 22
2.2.1 Communication Payload: Filter Functions 25
2.2.2 Summary of Filters Encountered in a Communication Payload 35
2.3 Satellite Filter Technology 37
2.3.1 Coaxial Cavity Filters 38
2.3.2 Waveguide Technology 39
2.3.3 Dielectric Resonator Technology 40
2.3.4 Space Qualification for Filter Units 40
References 42
3 Filter Synthesis Techniques 45
3.1 Introduction 45
3.2 Synthesis of Prototype Response 46
3.2.1 Characteristics of Filter Response 48
3.2.2 Chebyshev Response 52
3.2.3 Butterworth Response 53
3.2.4 Elliptic and Asymmetric Responses 55
3.3 Bandpass Filters Synthesis Using a Ladder Network 57
3.3.1 Lowpass Lumped Element Filter Prototype 57
3.3.2 Immittancc inverter Lowpass Lumped Prototype 60
3.3.3 Frequency Transformation 63
3.3.4 Impedance Inverters from a Discontinuity 67
3.4 Coupling Matrix Techniques 68
3.4.1 Analysis 71
3.4.2 Synthesis 72
References 73
4 Analysis and Design of Helical Resonators 75
4.1 Introduction 75
4.2 Helical Resonator Considerations 77
4.2.1 Transmission Lines Model of Resonators 77
4.2.2 Coaxial Line with Helical Inner Core 80
4.2.3 Helical Coaxial Transmission Line Resonators 83
4.3 Full-Wave Modeling of Helical Resonators 85
4.4 Quality Factor 91
4.5 Dielectric Loading and Tuning 96
4.5.1 Dielectric Loading 96
4.5.2 Tuning 98
References 102
5 Synthesis of Helical Resonator Fillers 105
5.1 Design of Helical Resonator Fillers 105
5.2 Input/Output Coupling 106
5.3 Inter-resonator Coupling 110
5.3.1 Tuning Screws 114
5.3.2 Decoupling Iris 114
5.3.3 Helix Axial Rotation 117
5.3.4 Effect of Cavity Width 118
5.4 Design Examples 119
5.4.1 Fourth-Order In-Line Filter 120
5.4.2 Sixth-Order Folded Filter 123
5.4.3 Realization Example 124
5.5 Summary 126
References 128
6 Quasi-Elliptic Helical Resonator Filters 131
6.1 Introduction 131
6.2 Cross-Coupled Helical Resonator Filters 132
6.2.1 Cross-Coupling by Means of DC Connection 133
6.2.2 Electromagnetic Cross-Coupling of Helical Resonators 136
6.2.3 An Eighth-Order Example with Both EM and Wire-Enabled Cross-Coupling 138
6.3 In-line Quasi-Elliptic Helical Resonator Filters 140
6.3.1 Parallel-Coupled Helical Transmission Lines 143
6.3.2 Parallel-Coupled Helical Resonators 145
References 165
7 Helical Resonator Filters with High Power-Handling Capability for Space Applications 169
7.1 Introduction 169
7.2 Multipactor 170
7.3 Space Qualifications Procedures 173
7.3.1 Verification 174
7.3.2 Analysis 177
7.3.3 Methods of Detection 177
7.4 Helical Resonators for Downlink Filters 179
7.4.1 Power Handling Analysis 179
7.4.2 Dielectric Covers 181
7.5 Summary and Conclusions 186
References 188
8 Summary 191
References 193
List of Abbreviations 195
About the Authors 197
Index 201
