A Dual-Polarized Millimeter Wave Microstrip Antenna with High Isolation and Low Cross-Polarization

Abstract

This paper proposes a dual-polarization millimeter wave microstrip antenna hold high port isolation and low cross- polarized level. The antenna is composed of four dielectric substrates with a total thickness of 1.016 mm. The vertically and horizontally polarized of the antenna are generated by the slot-coupled and microstrip-to-coaxial feeds, respectively. The feed position is put on the diagonal of the square patch. This feed structure enables the dual-polarization antenna to have high port isolation and low cross-polarized level. In addition, the metallized vias are introduced around the T-shaped microstrip line to further improve the polarized isolation, the cross-polarization discrimination, and the impedance matching characteristic. The simulation results show that the common bandwidth of |S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf> | less than -10dB for both polarization ports is from 24.5 to 27.5GHz (11.5%), the cross-polarization discrimination is higher than 53dB, and the port isolation is greater than 56dB. The antenna peak gain is 6.8dBi.