A Microwave/Millimeter-Wave Triple-Band Shared-Aperture Antenna with High Structure Reuse Efficiency

This paper presents a novel microwave (MW)/millimetre-wave (MMW) triple-band shared-aperture antenna. It operates as a patch antenna and a transmitarray (TA) antenna in the MW (3.6 GHz) and MMW bands (26 GHz and 39 GHz), respectively. The two types of antennas are integrated efficiently through aperture reuse. To obtain an appropriate focal-to-diameter ratio (F/D) for the TA, a frequency selective surface (FSS) is designed to replace the ground plane of the patch antenna. Due to the band-pass characteristic of the FSS, it can be equivalent to a ground plane for the patch antenna and allows waves to pass through for the TA. The proposed antenna demonstrates good performance in all bands and a high structure reuse efficiency. It can be a promising candidate for 5G multi-band applications.