Design and Analysis of Multi-Band Filtering Circuits

Contents
About the Author
Abbreviations and Acronyms
1 Background of Multi-band Filtering Circuit
	1.1 Importance of the Filtering Circuit
	1.2 Importance of the Multi-band Filtering Circuit
	1.3 Summary
	References
2 Analysis of Multi-Mode Resonator
	2.1 Multi-Mode Resonator (MMR)
		2.1.1 MMR Topologies
		2.1.2 Step-Impedance Resonator (SIR)
		2.1.3 Ring Resonator
		2.1.4 Multi-Stub Resonator
		2.1.5 Discussion
	2.2 Transmission Line Types Suitable for MMR
		2.2.1 Microstrip Line
		2.2.2 Coupled Line
		2.2.3 Slotline
	2.3 Summary
	References
3 Multi-band Bandpass Filter with High Selectivity
	3.1 High-Selectivity Multi-band Bandpass Filter Utilizing Asymmetrical Interdigital Coupled Lines and Circular Spiral Lines
		3.1.1 Introduction
		3.1.2 Dual-Band BPF Design
		3.1.3 Tri-Band BPF Design
		3.1.4 Quad-Band BPF Design
		3.1.5 Adding Circular Spiral Lines
		3.1.6 Circuit Implementation
	3.2 Compact Sept-Band Bandpass Filter Utilizing Single Multi-mode Resonator
		3.2.1 Introduction
		3.2.2 Schematic Topology
		3.2.3 Design of Multi-mode Resonator
		3.2.4 Controlling of Center Frequencies and Bandwidths
		3.2.5 Design of the Proposed Sept-Band BPF
		3.2.6 Circuit Implementation
	3.3 Octo-Band Bandpass Filter Based on Unequal-Width Cruciform Connected Resonator with Sharp Skirt
		3.3.1 Introduction
		3.3.2 Design of Multi-Mode Resonator
		3.3.3 Controllability of Center Frequencies and Bandwidths
		3.3.4 Circuit Implementation
	3.4 Summary
	References
4 Reflectionless Multi-band Bandpass Filter
	4.1 Reflectionless Architectures Overview
		4.1.1 Duplexer Structure
		4.1.2 Directional Filter Structure
		4.1.3 Symmetry and Duality Structure
	4.2 Proposed Reflectionless Architecture by Reused Resonances
		4.2.1 Circuit Structure
		4.2.2 Design Procedure
	4.3 Proposed Reflectionless Triple-Band Filter Prototype
		4.3.1 Circuit Design and Analysis
		4.3.2 Passbands Controllability Analysis
		4.3.3 Circuit Implementation and Measurements
	4.4 Proposed Reflectionless Tunable Dual-Band Filter Prototype
		4.4.1 Circuit Architecture
		4.4.2 Independently Tunable Resonances
		4.4.3 Calculated Transfer Function
		4.4.4 Absorbed Harmonic Signals
		4.4.5 Circuit Implementation
	4.5 Summary
	References
5 Balanced Filter with High Suppression
	5.1 Microstrip-To-Slotline Transition
	5.2 Slotline-Based Balanced Filter Details
		5.2.1 Proposed π-Type Slotline Structures
		5.2.2 Design of SRSRs and Controllability of the Passband
		5.2.3 Effects of the Integration of π-Type Slotline Structures on Stopband Suppression, Insertion Loss and Size
	5.3 Filter Implementation and Results
	5.4 Summary
	References
6 Slotline Based Multi-band Balun Filter
	6.1 High Selectivity Dual-Wideband Balun Filter Utilizing a Multimode T-Line Loaded Middle-Shorted CSRR
		6.1.1 Design of the TLMS-CSRR
		6.1.2 Controllability of Two Passbands
		6.1.3 Effect of Folded Slotline and π-Shaped Slotline Structure
		6.1.4 Circuit Implementation
	6.2 Quad-Band Balun Filter Using Dual-Mode Spiral Slotline Notched Structure with Enhanced Selectivity
		6.2.1 Design of Dual-Mode Notched Structure
		6.2.2 Design of Quad-Band Balun Filter
		6.2.3 Circuit Implementation
	6.3 Summary
	References
7 Switchable Filtering Diplexer Based on Reused L-shape Resonator
	7.1 Switchable Resonator Details
		7.1.1 Mechanism of Switching Techniques
		7.1.2 Effects of the Switching Technique on Frequency Selectivity, Insertion Loss and Size
		7.1.3 Co-Design Details of the Switchable Resonator and Input Matching Network
	7.2 Controllable Bandwidths and Center Frequencies
		7.2.1 Controlling of Bandwidths
		7.2.2 Controlling of Center Frequencies
	7.3 Diplexer Implementation and Results
	7.4 Summary
	References
8 Miniaturized 55-/95-GHz On-Chip Dual-Band Bandpass Filter
	8.1 Filter Design
		8.1.1 Structure Analysis of the Filter
		8.1.2 Comparison Between the Short- and Open-Circuited Stubs
		8.1.3 Controllable CFs, BWs and TZs
		8.1.4 Selection of Matching Capacitance
	8.2 EM Simulation
	8.3 Summary
	References
9 Summary and Conclusions