Co-Aperture Dual Circular Polarized Patch Antenna for Simultaneous Transmit and Receive

• Published in: IEEE antennas and wireless propagation letters 2023-11, Vol.22 (11), p.1-5
• Main Authors: Xie, Mingcong, Yao, Huiwei, Wei, Xizhang, Tang, Yanqun, Wang, Junyu, Hu, Dujuan
• Format: Article
• Language: English
• Subjects: Antennas; Aperture antennas; Apertures; Circular polarization; Co-aperture; Couplings; Decoupling; Directive antennas; dual circularly polarization; Ground plane; Mutual coupling; patch; Patch antennas; Receiving antennas; Sensors; simultaneous transmit and receive (STAR); Stars; Substrates
• ISSN: 1536-1225; 1548-5757
• DOI: 10.1109/LAWP.2023.3292429

A co-aperture dual circularly polarized antenna for simultaneous transmit (Tx) and receive (Rx) sensing systems is proposed in this letter. The antenna consists of a radiating patch, a dielectric substrate, and a ground plane. Embedding a rectangular slot in the center of the patch implements left-handed circular polarization for Tx and right-handed circular polarization for Rx. A pair of U-shaped slots (USS) with a 90° phase shift is placed into the ground plane for decoupling. When the USS works, the mutual coupling in the x - and y - direction cancels each other at the Rx port. As a verification, a prototype with the size of 0.43{\lambda _0} \times 0.43{\lambda _0} \times 0.01{\lambda _0} is fabricated and measured. The operating bandwidth, in which | {{S_{11}}} | and axial ratio are respectively less than -10 dB and 3 dB, is 4.32-4.42 GHz. Within this band, the measured peak realized gain is 5.4 dBi, and the isolation is better than 23 dB with a maximum of 34 dB. In comparison with other works, the proposed antenna is competitive in terms of antenna size, aperture efficiency, and total efficiency.