Broadband Dual-Polarized and Circularly Polarized Reflectarrays Using Planar Magnetoelectric Resonator

This article proposes a planar magnetoelectric resonator (PMER) as the element of broadband dual-polarized (DP) and circularly polarized (CP) reflectarray antennas (RAs). The PMER is realized by introducing a split in dual rhombic rings, which flats the vertical structure for magnetic resonance in common magnetoelectric (ME) element. Due to the isolated magnetic and electric resonant modes of the PMER, anisotropic characteristic is achieved to independently manipulate the reflection phase among two orthogonal polarizations and reflect CP incident wave in a wide bandwidth. Moreover, a simple modification method is presented for further expanding the operating band of CP element. For proof, a DP-RA and CP-RA prototype is fabricated and measured. The measured results reveal that 1-dB gain bandwidths of 17.5%/22.2% and 25.6% are observed for DP-RA and CP-RA, respectively, while maintaining low profiles and high aperture efficiencies. In particular, the measured axial ratio (AR) bandwidth of the PMER-based CP-RA reaches 66.7%.