A Rigorous Calculation of Coupling Iris in Waveguide Filter and Output multiplexers for Communication Satellites

摘要

The accurate coupling coefficient of coupling iris is presented, which is one of basic parameters in the design ofwaveguide filter and microwave multiplexer. First, the analytical solution for the cylindrical waveguide modal functions are achieved, the waveguide junctions of rectangular to rectangular and small rectangular to circular are studied uisng a rigorous mode-matching approach. so, Numerical integrals of Bessel function are avoided, and computation time is reduced. Second, the coupling coefficient of intercavity iris and input/output iris are achieved by chaining of the generilized scattering matrix and moving technique of s-parameters' reference plane. a series ofconvergence tests are carried out in order to optimize the number and nature of modes which shold be included in the numerical calculation.