Design and Implementation of the Canonical-Form-Like Coupling Scheme with Generalized Chebyshev Responses

Abstract

The canonical-form-like cross-coupling schemes of orders four, six and eight and its implementations are presented for coupled resonator filters. These coupling schemes show similar characteristics to that of the traditional canonical form coupling schemes. The fourth-order filter can be designed to have two pairs of transmission zeros locating on either real or imaginary frequency axes. An example filter designed with one pair of real frequency transmission zeros for selectivity and another pair of imaginary frequency transmission zeros for equalizing the group delay response is introduced. Measured and simulated performances are presented. In addition, the higher order coupling schemes are also discussed.