A dual-passband waveguide filter with a canonical structure for Ka-band satellite applications

This article presents the implementation techniques for a six-pole, dual-passband waveguide filter with an asymmetric canonical structure for Ka-band satellite applications. An asymmetric canonical structure is chosen, not only to increase the transmission zeros of dual-passband filters, but also to get high isolation between the input and output coupling elements. Very effective nonlinear equations are extracted to obtain the coefficients of a transfer function from the coupling matrix to synthesize a filter network. An appropriate equivalent circuit model for an asymmetric canonical structure is proposed to design a filter. To validate the proposed implementation approach, a six-pole, dual-mode, dual-passband filter for Ka-band satellite applications is realized. Very good agreement between the measured and computed responses is obtained.