Synthesis And Design Of Microwave Filters

In today's increasingly tense frequency resources, the filter, as the selected frequency components, is essential for modern communication systems, its role becoming increasingly prominent and its performance directly affecting the quality of the whole communication system. General speaking, there are two structures of modern microwave filters: single channel and multi-channel structure. The structure of single channel is simple and the multi-channel structure can generate transmission zeros by introducing cross-coupling. Single channel structures can use K or J transformation, Richard transformation and direct coupling to synthesize and realize, and the generalized Chebyshev synthesis can realize both structures.This paper studies the microstrip and cavity filter design ideas and methods, discusses the generalized Chebyshev filter theory and summaries the microwave filter design. Based on these theories, several microwave filters, meeting the requirements, are designed using HFSS simulation software, while hairpin filter is improved by introducing interdigital capacitor and get a new structure hairpin filter. At last, this paper discusses the co-simulation of cavity filter using ADS and HFSS simulation software to achieve rapid tuning filters to reduce the settling time.