Research On Synthesis Technology Of Microwave Filter

Filter is one of the most essential signal process components in the modern electronic circuit. With rapid development of the modern microwave technology, the application of filter in the microwave circuit is more important, and the design of high performance filter is meaning for the microwave circuit. Narrow-band, little volume, high restraint in stop band of filter is the trend of the filter development. Generalized Chebyshev function filter with transmission zeros in any-where has the advantage of high rectangle coefficient, narrow band, high power capacity, and is studied in the domestic and overseas widely.The paper mainly researches on the transfer and reflection function polynomial of Generalized Chebyshev function filter, synthesis of the lowpass prototype component values, the extraction of coupling matrix and the implementation of filter. At first, this paper simply introduces the types, the foundation of microwave network synthesis theory and the method of design the microwave filter, including the low pass prototype filter, frequency transformation and the low pass prototype filter just with one kind of reactance. Secondly, it especially introduces the transfer function polynomial and reflection function polynomial of Generalized Chebyshev function filter which is made by transmission zeros through recursive technique,synthesis method of the lowpass prototype component values, extraction of coupling matrix. Finally, it shows an concretely example of Symmetry Generalized Chebyshev function filter design, using the microwave simulation software which can simulate and optimize the initial dimension values, so as to gain the final dimension values. The simulation result shows that this synthesis method is feasibility.