Dual-Band Dual-Circularly Polarized Shared-Aperture Antenna for UHF-wave and Millimeter-wave applications

In this paper, a dual-band dual-circularly polarized shared-aperture antenna for UHF-wave (0.3-3GHz) and millimeter-wave (30-300GHz) bands is proposed. In the millimeter-wave band, the antenna adopts a planar reflect array antenna. In the UHF band, the metal ground of Millimeter-wave reflectarray is reused as its radiation patch., so as to realize the dual-band shared-aperture. The planar reflect array antenna uses circularly polarized microstrip patch antenna as the feed source. Different phase shifts are realized by the size of each microstrip patch on the control plane, and the phase delay of the feed irradiation to the array surface is compensated to realize in-phase radiation and achieve high far-field gain. The low-frequency antenna uses a double-port feed with equal amplitude and phase difference of 90 degrees to realize circularly polarized wave radiation. In the millimeter-wave band, the bandwidth covers 29.5-33GHz and the gain can reach 27.5dBic. In the UHF band, the operating frequency band is 0.975-0.988GHz, and the gain can reach 6.5dBic. It has potential application value in UHF-wave and millimeter-wave bands.