A Dual-Mode Coupling MMW Antenna With Dual Polarizations and Wide Scanning Angles

Millimete-wave (MMW) communication and sensing systems suffer from the challenge of realizing dual-polarized phased array antenna with large beam-scanning angles, due to the array unit can hardly having the radiation pattern with wide 3 dB beamwidth in both orthogonal planes (one is the beam-scanning plane). In this letter, we propose a dual-mode coupling radiation mechanism to integrate a monopole mode and a patch mode for obtaining 3 dB beamwidth larger than 120° in both two orthogonal planes. Hence, the array cascaded from the antenna unit can realize a wide beam scanning of −60°∼+60° within gain degradation of less than 3 dB in both ±45° polarizations. Based on this principle, a ±45° dual-polarized antenna unit is designed, and a prototype of a 1 × 8 ±45° dual-polarized phased array is fabricated. Experiments demonstrate that the MMW array operating in 25.5 GHz to 28 GHz (active |<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub>|< −10 dB) can scan from −60° to +60° with gain fluctuations less than 3 dB. The proposed MMW antenna can be applied to B5G/6G MMW communications and sensing.