Research And Design Of Substrate Integrated Waveguide And Stepped Impedance Resonator Filters

The filter is an essential and key component in RF/microwave communication andradar systems. The Substrate Integrated Waveguide (SIW) as a new type waveguidestructure, it not only inherits advantages of the traditional metal waveguide, but also hasadvantages of the planar microstrip circuit. Therefore, the SIW provides a usefultechnology with low-cost, high power capability, high quality-factor, compact size andeasy integration features with planar circuits. The SIW represents an emerging and verypromising candidate for the development of circuits and components operating in themicrowave and millimeter-wave region, and it is constantly becoming research hotissues. The length dimension of Stepped Impedance Resonator (SIR) can be reducedwithout decreasing no-load quality factor of the resonator. And the SIR can control itsparasitic spurious frequency when obtaining the desired resonance frequency. It hasbeen becoming a very popular technology to achieve low profile and high performancefilter design with flexible structure and high degree of freedom. This thesis focuses onthe research and design of SIW filter and SIR filter. The main research and designresults of this thesis are as follows:1. Design a Ka-band SIW bandpass filter, and the microwave filter design theoryand SIW technology are the design basis. The inductive metal window and fourth-ordercross-coupled structure are used to design the SIW filter. The measurement andfull-wave electromagnetic simulation results of the filter are consistent, it meets thedesign requirements and validates the design method.2. Design some X-band SIW dual-mode bandpass filters in the case of SIWtechnology integrated with dual-mode resonant theory. Single cavity dual-mode anddual-cavity dual-mode structure are used to design the two types of SIW dual-modebandpass filters, respectively. And by loading the second-order split ring resonatordefected ground structure (SRR DGS) with the help of its notch and bandgapcharacteristic, the parasitic and spurious passband of the SIW dual-mode filters canachieve suppression. And the measurements and full-wave electromagnetic simulationresults of the SIW dual-mode filters are consistent to verify the design. 3. Propose and design a novel dual-band bandpass filter using the steppedimpedance resonator (SIR) structure with high frequency selectivity for WLANapplications (2.45/5.2GHz). The measurement of the filter is consistent with thefull-wave simulation result. It can achieve dual passband characteristics, and meets thedesign specifications. The design of the filter is compact and it has a high degree offreedom. By using0ofeed structure, it can generate two transmission zeros on bothsides of the two passbands, respectively. And these four transmission zeros caneffectively improve the frequency selection characteristics of the dual-band filter.