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In this paper, using the generalized cut Chebyshev functions integrated cross-coupling matrix , developed on this basis used in WCDMA communication system includes a directional coupler , duplexer , low-pass filter and a band-pass filter passive the components of the device . First, the development of mobile communications technology and WCDMA frequency division , the basic theory of the filter on the structure of the major categories and filter design ; comprehensive theory of Chebyshev unitary matrix and its generalized cut by two-port lossless network initial matrix then elimination to simplify cross coupling matrix suitable for applications in engineering , and has two transmission zero -order cross coupling matrix of generalized Chebyshev filter instance . Secondly , according to the frequency of the WCDMA system requirements , design , under the center of the channel frequency is 1950MHz and 2140MHz relative bandwidth are 3.08% and 2.80% generalized cut Chebyshev diplexer , and the degree of coupling 40 ± 2dB directivity greater than 30dB directional coupler . In order to achieve the index requirements suppress the secondary , three and higher order harmonics , it is in series with a low pass filter in the emitting end of the diplexer . Finally, the design of a directional coupler , a duplexer , low pass filter , band pass filter , respectively, in the HFSS software simulation optimization , and then drawing the entire assembly constituted by the various passive components , processing, debug and test final test results and simulation results are consistent indicators meet the customer requirements . Also confirmed a series of cross-coupling procedures using MATLAB generalized cut good practical value than Chebyshev filter design .
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