The Research Of Cross Coupling Of Cascaded Filter

In this paper, two building blocks of cross coupling pseudoelliptic filter are cascaded to get high selectivity of filter characteristic. Slots are used to realize the coupling between cavities and standard waveguides are made as the input and output port to simplify the connection with other equipments. Methods of extracting various of coupling parameters with CAD tools are introduced, which can help us save design time. We present the network synthesis technique of coupling matrix, thus we can synthesis the coupling matrix according to the required property and the network topology structure. The relationships between s parameter and coupling matrix are given. Having mastered the technique above, we can design and simulate the filter from the required property. At the end of this paper a 4-order x-band cross coupling cascaded filter is given as an example.