A Multipolarized Metal-Only Reflectarray Antenna

A multipolarized metal-only reflectarray antenna (MPMORA) is proposed and investigated in this communication. The reflectarray is an all-metal planar structure and is composed of unit-cells featuring perpendicularly placed size-variable slots carved in a metal sheet. Owing to negligible interactions between orthogonal slots of the unit-cell, a multipolarized metal-only reflectarray with dual-linear and dual-circular operations can be realized by rotation of a linearly polarized (LP) feed with 0°, 45°, 90°, and 135°, respectively. For proof-of-concept, a prototype hosting 441 unit-cells and operating at X-band is manufactured and measured. The testing data reveals that the proposed design can achieve reasonable 1 dB gain drop bandwidths and peak aperture efficiencies for all polarizations, for instance, 15.3% and 45% in the case of right-hand circular polarization (RHCP). Moreover, the 3 dB axial ratio bandwidths for RHCP and left-hand circular polarization (LHCP) are also wide, which are 26% and 39%, respectively. These satisfactory behavior as well as the metal-only configuration make our design a competitive candidate for multi-polarization applications.