Compact Dual-Band, Dual-Circularly-Polarized Shared-Aperture Antenna Based on the Structure Reuse of a DR

This letter proposes a compact, dual-band, dual circularly-polarized shared-aperture antenna based on the structure reuse of a dielectric resonator (DR) structure. The proposed antenna reuses a smaller DR, originally designed for the high-band (HB) radiator, as the radiating structure for the low-band (LB). It incorporates a LB right-hand circularly polarized (RHCP) dielectric resonator antenna (DRA) and a HB left-hand circularly polarized (LHCP) DRA into a compact shared-aperture construction, attaining a high aperture reuse efficiency. The RHCP radiation in the LB is produced by the DR mode, and the LHCP radiation in the HB is produced by the combination of the patch mode and the DR mode. Two operating bands can be adjusted independently. Additionally, the cross-band port isolation is improved by using band-stop filtering decoupling technology. For verification, an antenna prototype with a transverse size of 0.59
λ_L
×0.59
λ_L
is fabricated. Measured results show that the proposed antenna has a -10-dB impedance bandwidth of 17.5% and 11.8%, and a 3-dB AR bandwidth of 7.4% (RHCP) and 7.47% (LHCP). The measured cross-band port isolation of more than 33.2 and 31.3 dB are obtained in the LB and HB, respectively.