A Bandpass Filter–Polarizer Based on a Dielectric Multilayer with Strip Conductor Gratings

A new design of a multilayer bandpass filter is proposed, in which each resonator consists of two identical dielectric layers with parallel strip conductor gratings on their outer surfaces and an orthogonal strip conductor grating between the layers. The filter designed on the basis of crossed gratings works simultaneously as a polarizer transparent in a specified frequency band if the electric field vector of a wave is parallel to the outer strip conductors but reflects waves with an orthogonal polarization. The data from a numerical electrodynamic analysis of a 3D model of the proposed device agree well with the results of the measurements performed on the fifth-order filter–polarizer prototype with a relative bandwidth of 14% and a central frequency of 13.4 GHz. The microwave power loss in the filter passband is ~1.2 dB under parallel polarization of the electromagnetic wave and more than 40 dB under orthogonal polarization.