Single-layer compact dual-band dual-circularly polarized antenna based on proximity-coupling feed patches

This paper presents a single-layer compact antenna with capability of realizing dual-sense circularly polarized (CP) radiation at two distinct frequency bands. The design employs multiple truncated-corner patches of different sizes operating in their fundamental modes, which are proximity-coupled through a probe-fed microstrip line. This configuration enables a single-layer structure, compact footprint, and flexible frequency-ratio tuning. This distinguishes the proposed design from the other related works, which are commonly multi-layer and large size due to the utilization of stack configuration or higher-order mode. Validation demonstrates that the proposed antenna exhibits dual-band operation at 5.2 and 6.5 GHz, with the operating bandwidths of 1.6% and 1.8%. Over these bands, the broadside gain values are higher than 6.0 dBi and peak at 6.5 dBi.