Ultralow-Profile Conformal Antenna With Large Axial Ratio Bandwidth for Flapping-Wing Insects

作者：Hu, Zhiwei; Wang, Qiyang; Wang, Wentao; Tu, Hao; Huang, Wen; Chen, Qiang; Sang, Lei^*

来源：IEEE Antennas and Wireless Propagation Letters, 2023, 22(10): 2552-2555.

DOI：10.1109/LAWP.2023.3296513

• Flexible conformal circularly polarized antenna
• miniaturization
• ultralow-profile
• wide axial ratio bandwidth

This letter presents an ultralow-profile flexible circularly polarized (CP) antenna that can be conformal to the wing of flapping-wing insect aircraft. The antenna is manufactured by laminating a single metal layer on a flexible polyimide substrate with a thickness of 0.125 mm (0.0025 lambda). Adopting an ingenious design combining asymmetric coplanar waveguide (ACPW) and a slot structure shaped like an N is used in the proposed antenna, which achieves both ultra-low profile and wide axial ratio bandwidth. ACPW is used for antenna feed, and the combination of N-like slot and ACPW can form current radiation at the slit that is orthogonal in space and time respectively, and similar in intensity. The proposed antenna realizes -10 dB impedance bandwidth of 40% (4.5-6.8 GHz) and 3 dB axis ratio bandwidth of 37% (4.6-6.7 GHz), with a gain larger than 3.5 dBi. When the antenna is bent due to wing flapping, the antenna performance remains stable.