Wideband Folded Reflectarray Using Novel Elements With High Orthogonal Polarization Isolation

A wideband folded reflectarray antenna (FRA) operating in a frequency band of 11–15 GHz is proposed in this communication. It consists of novel dual-polarization elements with high orthogonal polarization isolation. A two-layer element structure is used to control the reflection phase of two orthogonally polarized waves independently and the element presents a large phase variation of about 700° and approximately linear phase curves. Meanwhile, the multifrequency phase matching method is applied in the FRA design. A 30% bandwidth for a 1-dB gain drop, a peak aperture efficiency of 49.1%, and sidelobe levels below −14 dB are achieved. Factors with strong influences on the aperture efficiency are discussed. The simulated results are experimentally verified by an FRA prototype fed by an open-ended waveguide.