| Coaxial cavity filter is widely applied in modern wireless communication, digital television broadcasting, satellite navigation, remote sensing and radar systems, for its high power capacity, low insertion loss, far spurious pass-band. In television transmission system, by using a duplexer or a multiplexer, two or more channels could be transmitted via one antenna. It requires duplexer with high power, low insertion loss, good matching, high channel rejection and other properties. And if transmitting two adjacent channels, the performance of the duplexer is increasingly stringent, which the design of the filter is more difficult.This research is based on the project of a television transmission equipment company. The main contents are as following:(1) Complete the Cross-coupling Filter Synthesis Software based on MATLAB platform, which can be quickly integrated the Coupling Matrix of 2N symmetric network cross-coupling filter.(2) Analyze and discuss the electromagnetic properties of Coaxial Cavity Resonator, including Resonant Frequency, Coupling structure and External Q-Value.(3) Complete the filter design for a television transmitting Equipment Company, designed a coaxial cavity filter works in channel 40, now the product has been successfully applied to the television transmitters.(4) Design and Simulate a coaxial filter that can be used for the adjacent channel duplexer; the filter has 6 resonators composed of two cross-coupler that introduces 4TZs to increase the filter Band rejection level.With the development of filter design technology, microwave filter of any structure is not difficult overall, the future of microwave filter research focuses on the development and application of new materials, fast simulation technology and automated tuning technology. |
PDF Full Text Request