A Novel Four-Port Phase Mode Antenna and Its Application in Multipolarization Wide-Angle Scanning Phased Array

In this article, a novel four-port phase mode antenna (PMA) with multipolarization beam scanning capability is proposed. By adjusting the phase difference between feeding ports, the four-port PMA can excite different phase modes allowing for multipolarization beam scanning. It is observed that the even mode and odd mode, the basic modes of the PMA, correspond to the different characteristic modes in the antenna. In addition, a detailed explanation of the variation law of phase modes is provided based on the characteristic mode theory. Simulated and measured results demonstrate that the proposed four-port PMA can achieve independent vertical polarization and horizontal polarization beam scanning in the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$yo\textit {z}$ </tex-math></inline-formula> plane. By combining two orthogonal polarized beams, the antenna can achieve various other polarizations. Furthermore, its application is investigated in wide-angle scanning phased array. For the 1-D generalized array based on the four-port PMA, the measured results of vertical polarization, horizontal polarization, oblique +45° polarization, and right circular polarization (RCP) indicate that the maximum scanning angle of array can reach more than ±80° in the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$yo\textit {z}$ </tex-math></inline-formula> plane while maintaining the cross-polarization level below −20 dB. Obviously, the four-port PMA offers more freedom in beamforming, which provides a good prospect for the development of radar and wireless communication.