Stripline and Microstrip Resonators and Bandpass Filters

Alexander Zakharov, PhD, DSc, is Professor on the radio engineering faculty at National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute.” A Senior Member of IEEE, he has published more 100 scientific articles, with more 20 appearing in IEEE journals since 2017. His international experience includes positions at Paratek Microwave and Trilithic developing bandpass filters and tunable filter technologies. Sergii Litvintsev, PhD, is Associate Professor on the radio engineering faculty at National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute.” A Member of IEEE, he received his PhD in radio engineering from Kyiv Polytechnic Institute in 2023 and has taught radio engineering at the university since 2000.

• Preface xvii1 Introduction 12 Basic Concepts of Electrical Filter Theory 92.1 ABCD Parameters 92.2 Open-circuit and Short-circuit Parameters 122.3 Scattering Parameters 132.4 Relationships Between Two-port Network Parameters 142.5 Immittance Transformation by Two-port Network 142.6 Bandpass Filter Characteristics 162.7 Chebyshev Low-pass Prototype Filter 172.8 Relationship Between Transfer and Reflection Functions 223 Bandpass Filters with Parallel-type Resonators and Simple Couplings 253.1 G. Matthaei's Design Method 253.2 Coupling Coefficient Between Resonators 283.3 External Q-factor of Resonators 323.4 Bandpass Filter Design Examples 354 Influence of Dissipative Loss on Bandpass Filter Frequency Response 394.1 Effect of Loss at Center Frequency of Passband 394.2 Influence of Loss on BPF Performance 404.3 Unloaded Quality Factor Qu of Resonator 414.4 Physical Factors Determining Unloaded Quality Factor Qu of Microstrip and Stripline Resonators 435 Transmission Line Resonators 535.1 Uniform Resonators and Their Critical Frequencies 535.2 Nonuniform Transmission Line Resonators 565.3 Stepped-impedance Resonators 605.4 Synthesis Example of Stepped-impedance Resonators at Given Critical Frequencies 655.5 Optimization of Nonuniform Transmission Line Resonators 685.6 Parametric Synthesis 725.7 Structural-parametric Synthesis 845.8 Microstrip BPF with Resonator Obtained by Structural-parametric Synthesis 915.9 Transmission Line Resonators with Mutually Opposite Critical Frequencies 926 Bandpass Filters with Cross-couplings 976.1 Triplet Bandpass Filters 976.2 Quadruplet Bandpass Filter 1006.3 Quadruplet BPF with Two Cross-couplings 1036.4 Cascaded Quadruplet Filters 1056.5 General Coupling Matrix 1076.6 Coupling Matrix Modification Using Through-type Resonators 1107 Bandpass Filters with Mixed Couplings 1217.1 Representation Forms of Mixed Coupling Between Resonators 1227.2 Direct and Inverse Problems of Mixed Coupled BPFs 1257.3 Triplet BPF with Mixed Cross-coupling 1277.4 Quadruplet BPF with Mixed Cross-coupling 1457.5 Triplet BPF with All Mixed Couplings 1557.6 Comments on BPFs with Mixed Couplings 1648 Mixed Coupled High-order Inline and Cascaded Filters 1698.1 Design Method of BPF with Mixed Couplings Between Adjacent Resonators 1698.2 Cascaded Two Triplet BPFs with Mixed Cross-couplings 1738.3 Cascaded Quadruplet and Triplet BPFs with Mixed Cross-couplings 1768.4 Cascaded Two Quadruplet Bandpass Filters with Mixed Cross-couplings 1778.5 Cascaded Two Quadruplets and One Triplet BPFs with Mixed Cross-couplings 1818.6 Stripline Realization of CT Filter with Mixed Cross-couplings 1839 Resonators with One or Two Antiresonant Frequencies Close to Operating Resonant Frequency 1899.1 Features of Resonators with Multiple Critical Frequencies 1899.2 Transmission Line Resonators with One Antiresonant Frequency Close to Main Resonance Frequency 1919.3 Lumped-distributed Resonator with One Antiresonant Frequency Close to Main Resonance Frequency 1999.4 TL Resonators with Two Antiresonant Frequencies Close to Operating Resonant Frequency 2059.5 LD Resonators with Two Antiresonant Frequencies Close to Operating Resonant Frequency 2209.6 Systematization and Basic Properties of Resonators with One or Two Antiresonant Frequencies Close to Operating Resonant Frequency 23110 Filters with Simple Couplings and Multiple Transmission Zeros Generated by Resonators 23710.1 BPF with Simple Couplings and Resonators with One Antiresonance Frequency Close to Main Resonance Frequency 23710.2 BPF with Simple Couplings and Resonators with Two Antiresonance Frequencies Close to Operating Resonant Frequency 24310.3 Influence of Destabilizing Factors on BPF Frequency Responses 26210.4 Basic Properties of BPF with Simple Couplings and Multiple TZs Generated by Resonators 26511 Filters with Mixed Couplings and Multiple Transmission Zeros Generated by Resonators 26911.1 BPFs with Mixed Couplings and Resonators with One Antiresonance Frequency Close to Main Resonance Frequency 26911.2 BPFs with Mixed Couplings and Resonators with Two Antiresonance Frequencies Close to Main Resonant Frequency 27111.3 Microstrip Second-order Mixed Coupled BPF with Multiple TZs 27711.4 Properties of BPF with Mixed Couplings and Multiple T Zs Generated by Resonators 28712 Stripline Bandpass Filters 29112.1 Coupling Between Uniform Stripline Resonators 29212.2 Coupling Between Stepped-impedance Stripline Resonators 29612.3 BPF with SIRs 30012.4 Coupling Coefficients at Higher Resonant Frequencies 30612.5 Invariance of Coupling Coefficients Relative to Dielectric Constant 31112.6 Millimeter-wave Stripline Bandpass Filters 31712.7 Influence of Metal Layer Thickness on Coupling Coefficients and Frequency Responses 32312.8 Stripline BPF with Two Different Dielectric Substrates 32812.9 Stripline Delay Line Filter with Two Different Dielectric Substrates 33112.10 Stripline Duplexers 33312.11 Properties of Stripline BPFs with Two Dielectric Substrates and Metal Layer 33713 Microstrip Resonators and Bandpass Filters 34313.1 Coupling Between Stepped-impedance Microstrip Resonators 34313.2 Compact Mixed Coupled Microstrip Triplet BPFs 35013.3 Higher-order Mixed Coupled Compact Microstrip BPFs 36013.4 Mixed Coupled Stepped-impedance Resonators in Microstrip BPFs on Thick Substrates and Low-mounted Screen 36714 Bandpass Filters with Wide Stopband 38914.1 Special Connecting Points on Quarter-wave and Half-wave Resonators 38914.2 Microstrip BPF with Λ/4 Resonators and Special Connecting Points 39214.3 BPF with Λ/4 Resonators and SIRs Coupled by Quarter-wave Segments 39414.4 Transmission Line BPF with One Passband 39815 Tunable Resonators 40515.1 Resonators with Variable Capacitances, Tuning Limitations 40515.2 Resonators with Variable Capacitances and Inductances, Tuning Limitations 42715.3 Hairpin Resonators Tuned by Capacitance 43415.4 Unloaded Quality Factors of Tunable Resonators 44116 Tunable Bandpass Filters 45716.1 Varactor-tuned Microstrip BPF with Hairpin and Combline Resonators 45716.2 Varactor-tuned Microstrip BPF with Two Operating Regimes 46216.3 Bandpass Filter with Combined Frequency Tuning 46716.4 Combline Bandpass Filter with Ferroelectric Capacitors 46917 Dual-mode Resonators and Bandpass Filters 47717.1 Dual-mode Resonators with Uniform TL Segments 47717.2 Dual-mode Resonators with SILS 48817.3 Dual-mode Resonators with Two Transmission Zeros 50317.4 Meander Dual-mode Resonators and Bandpass Filters 51217.5 Reconfigurable Loop-type Dual-mode Resonators and Filters 526Contents xvReferences 537Index 541