A Novel Tri-band Circularly Polarized Metasurface Antenna Based on Characteristic Mode Analysis

• Published in: IEEE antennas and wireless propagation letters pp. 1 - 5
• Main Authors: Ren, Mingxing, Li, Ji, Zhao, Hongmei
• Format: Journal Article
• Language: English
• Published: IEEE 31.05.2024
• Subjects: Antenna feeds; Antenna measurements; Antennas; characteristic mode analysis(CMA); dual-sense; metasurface(MTS); Microstrip; Microstrip antennas; Reflector antennas; Slot antennas; tri-band
• DOI: 10.1109/LAWP.2024.3408218
• ISSN: 1536-1225

This paper proposes a novel tri-band dual-sense circularly polarized (CP) metasurface (MTS) microstrip antenna based on characteristic mode analysis (CMA). The antenna consists of modified 3×2 MTS units, orthogonally feeding slots, and a T-shaped power divider as the feeding network. CMA is initially conducted on the MTS units to elucidate the operational principles of the proposed antenna. Rectangular patches are replaced by curved rings with lower radiation, and adjustments are made to the corners of the units to achieve CP and mitigate reverse current in resonant modes. Subsequently, CMA is performed on the modified MTS units with the feeding slots to excite resonant modes. The results show that three pairs of orthogonal modes excited by the feeding slots are achieved at 7.75GHz, 8.8GHz, and 9.8GHz, respectively forming CP. Finally, the inclusion of a T-shaped power divider is simulated to validate the antenna's performance. A prototype experiment verifies the principle and design methodology, with measurements agreeing well with simulation results.