Design of Filtering Folded Transmitarray Antenna Through Exploiting Its Main Reflectarray

A filtering folded transmitarray antenna (FTA) is presented for the first time through exploiting its main reflectarray in this paper. A high frequency-selective polarization conversion reflective surface (PCRS) is used as the main reflectarray of proposed filtering FTA design instead of conventional wideband polarization conversion reflective surface. The periodic element of frequency-selective bandpass PCRS is mainly composed of a rectangular ring and the metallic ground. A polarization conversion reflection zero can be introduced in the PCRS design by the coupling effect of the degenerated resonance of the dual-mode rectangular ring. It is easy to flexibly adjust the position of polarization conversion reflection zero to be at the upper or lower stopband of the PCRS. For the verification of the proposed filtering FTA design method, a prototype antenna has been presented as an example with its center frequency of 30GHz. Good filtering performance of the proposed antenna could be observed in the simulated results, which verifies the proposed filtering FTA design method.