Analysis And Design Of The General Chebyshev Filter

Filter is one of the most important equipments in the wireless technology, it can be used to divide or assemble various frequencies, like transducer, diplexer etc. As the rapid development of wireless communications, the frequency spectrum becomes more crowed, specifications for filters have tended to become very much more severe, which are commonly met only by those filters with stringent frequency-selectivity, small size and sharp cutoff skirts. These filters are designed only by using cross-coupled resonators to generate finite transmission zeros. The synthesis and design of coupled resonator filters with additional cross-couplings between nonadjacent resonators has been the subject of intense research efforts due to their importance.This thesis gave emphasis to the synthesis and design of the general Chebyshev filters, and also, especially studied related theories and technologies about the cross-coupling model.Firstly, the synthesis and design of the Chebyshev filters and frequency transformation was given as the basic theory. Further more, the theories of the general Chebyshev filters with transmission zeros was introduced, and on this background prove that the position of each transmission zero or pair of zeros in stop band of the Chebyshev filters composed of cascaded-quadruplet(CQ) and cascaded-triplet(CT) is independently modified; Then several optimizing methods to get the coupling matrix, namely, GA and Solvopt etc. lastly some typical filters were designed based on the synthesis theory of the filters given before, the result of the simulation and experimentation were matched very well, so the validation and efficiency of the synthesis method was demonstrated.