Low-Profile Dual-Band Dual-Circularly-Polarized Antenna Hybridizing Folded Transmitarray and Multi-Feed Transmitarray

• Published in: IEEE antennas and wireless propagation letters 2025, p.1-5
• Main Authors: Tong, Yixin, Cao, Wenquan, Wang, Chuang, Bo, Xin-Zhi, Yang, Yusheng, Liu, Zhen-Guo
• Format: Article
• Language: English
• Subjects: Antenna arrays; Antenna feeds; Apertures; Compact structure; Dual band; dual-circularly-polarized; Feeds; folded transmitarray (FTA); low profile; multi-feed transmitarray; Patch antennas; Reflector antennas; Satellite antennas; satellite communication; Satellite communications; shared-aperture; Transmitting antennas
• ISSN: 1536-1225; 1548-5757
• DOI: 10.1109/LAWP.2024.3514755

This letter proposes a novel low-profile dual-band dual-circularly-polarized antenna with a compact structure. The proposed shared-aperture antenna hybridizes a folded transmitarray (FTA) at the K band and a multi-feed transmitarray (TA) at the Ka band. Through adopting the technique of folding and multi-feed, we can reduce the height-to-diameter ratio (H/D) to only 0.19. By using a dual-band receiver-transmitter (Rx-Tx) structure on the TA, we achieve left-hand circular polarization (LHCP) at the K band and right-hand circular polarization (RHCP) at the Ka band simultaneously. The low-band feed using patch antenna is placed in the middle of the reflectarray (RA) aperture. The high-band feeds composed of patch arrays are placed around the low-band patch and fed by a power divider. Through the novel feed configuration and feed network, we can make the entire structure very compact and avoid feed blockage. An antenna prototype operating at the 20GHz and 30GHz bands is designed, fabricated and measured. The measured results show that the impedance bandwidths are 12.2% (19.3-21.8GHz) and 8% (28.8-31.2GHz), respectively. The 3-dB axial ratio bandwidths are 18.7% (18.9-22.8GHz) and 11.4% (28-31.4GHz), respectively. The proposed antenna with low profile and compact structure is well realized to offer a promising candidate for satellite communication.