Filtering two-element waveguide antenna array based on solely resonators

This paper presents a design approach of a filtering antenna arrays based on the coupling matrix theory. The approach generates filtering functionality using the resonating array radiating elements and the resonator based feed network regardless to the physical structure. To implement the approach, a novel topology for a two-element array is presented, here three rectangular waveguide cavity resonators have been employed to form the filtering array. The array has a fractional bandwidth of 10% at the centre frequency 10 GHz with a reflection coefficient magnitude within the passband of 20 dB. The realised gain over the passband is 9.8 ± 0.4 dBi. The array has been fabricated and the measurements are in very good agreement with the simulations, validating the approach.