| Along with the rapid development of information industry, wireless communication has become one of most popular technology in the 21st century. Filters that were wide used in system play an extremely important role in RF/Microwave circuit, high selectivity and miniaturization has become hot point in the filters designing process. Given these actual needs, we launched the topic with the goal of high selectivity and miniaturization. Based on the approximating function, from cavity to micro-strip, we elaborated the quickly optimization design method of high-performance filters and related products in various aspects.Firstly, after reviewing the history and expounding on the present situation, we analyzed the development trend of modern filters. Secondly, we proceed from cross-coupling of multi-channel structural which base on generalized Chebyshev filter function to extract the generalized Chebyshev coupling matrix by means of direct synthesis and optimized extraction method respectively. Then the article gives process of designing method about the different frequency combiner. Experimental date show the designed combiner has good performances. These jobs are of great value to highly quality cavity filters. Certainly there are many worthwhile conclusions to be drawn, which plays very important role in theory research and engineering practice. Later, we studied the miniaturized technology of micro-strip filters. The cross coupling theory which containing source-load were successful used in multilayer structure to realize parasitic extraction. Then we present a method based on optimization method integrated in software itself to extract parameters. The computed results of designed ring-split resonator band-pass filters are in good agreement with experimental date. These works are of great value to micro-strip filter miniaturized design and computer-aided debugging. |
