Planar High-Gain Circularly Polarized Element Antenna for Array Applications

This paper proposes a planar high-gain circularly polarized element antenna that can be used for array applications. The substrate-integrated waveguide (SIW) cavity is designed to support dual-resonant modes, the TE₁₂₀-like and TE₂₁₀-like modes, for the implementation of circularly polarized radiation performance. Four rectangular radiation slots and a large perturbation, introduced by inserting a metallic via-brick into the SIW cavity, are deployed to achieve a high simulated gain of 10.28 dBi at 6.65 GHz for the proposed element. As a demonstration of an array application, a 4 × 4 array antenna is designed using the proposed element with a compact beam-forming network. Experiments are carried out to verify the designed prototypes. The measured peak gains of the designed element and array antennas are 9.6 and 20.1 dBi, respectively, which include the loss from SMA connectors. Good agreement between simulated and measured results is obtained.