Modeling and Design of Microwave- Millimeterwave Filters and Multiplexers

Title of dissertation: MODELING AND DESIGN OF MICROWAVE-MILLIMETERWAVE FILTERS AND MULTIPLEXERS Yunchi Zhang, Doctor of Philosophy, 2006 Dissertation directed by: Professor Kawthar A. Zaki Department of Electrical and Computer Engineering Modern communication systems require extraordinarily stringent speci…cations on microwave and millimeter-wave components. In mobile and integrated communication systems, miniature, ultra-wideband and high performance …lters and multiplexers are demanded for microwave integrated circuits (MICs) and monolithic microwave integrated circuits (MMICs). In satellite communications and wireless base stations, small volume, high quality, high power handling capability and low cost …lters and multiplexers are required. In order to meet these requirements, three aspects are mainly concerned: design innovations, precise CAD procedure, and improved manufacturing technologies. This dissertation is, therefore, devoted to creating innovated …lter and multiplexer structures, developing full-wave modeling and design procedures of …lters and multiplexers, and integrating waveguide structures for MICs and MMICs in Low Temperature Co-…red Ceramic (LTCC) technology. In order to realize miniature and broadband …lters, novel multiple-layer coupled stripline resonator structures are proposed for …lter designs. The essential of the resonators is investigated, and the design procedure of the …lters is demonstrated by examples. Rigorous full-wave mode matching program is developed to model the …lters and optimize the performance. The …lters are manufactured in LTCC technology to gain high-integration. In order to obtain better quality than planar structures, original ridge waveguide coupled stripline resonator …lters and multiplexers are introduced for LTCC applications. Planar and waveguide structures are combined in such …lter and multiplexer designs to improve the loss performance. A rigorous CAD procedure using mode matching technique is developed for the modeling and design. To design wideband multiplexers for LTCC applications, ridge waveguide divider junctions are presented to achieve wideband matching performance. Such junctions and ridge waveguide evanescent-mode …lters are cascaded together to realize the multiplexer designs. The design methodology, e¤ects of spurious modes and LTCCmanufacturing procedure are discussed. Some other important issues of microwave …lter and multiplexer designs addressed in this dissertation are: (1) Systematic approximation, synthesis and design procedures of multiple-band coupled resonator …lters. Various …lter topologies are created by analytical methods, and utilized in waveguide and dielectric resonator …lter designs. (2) Dual-mode …lter designs in circular and rectangular waveguides. (3) Systematic tuning procedure of quasi-elliptic …lters. (4) Improvement of …lter spurious performance by stepped impedance resonators (SIRs). (5) Multipaction e¤ects in waveguide structures for space applications. MODELING AND DESIGN OF MICROWAVEMILLIMETERWAVE FILTERS AND MULTIPLEXERS