Design of bandpass filters composed of dielectric layers separated by gratings of strip conductors

Abstract

We derive the design formulas for novel multilayer bandpass filters in which every dielectric layer (resonator) is separated from the adjacent layer or external medium by a grating of strip conductors. Every grating acts as a semireflecting mirror. Such novel filters have wide stop bands compared to conventional filters with multilayer dielectric mirrors between resonators at the same passband width. The parameters of the lowpass, lumped-element prototype filter, as well as the theory of resonator-coupling coefficients, are considered in our approach. The computed frequency response of the fifth-order Chebyshev filter that was synthesized using the proposed formulas is also presented.