Dual-polarized patch antenna array with hemispherical beam coverage

A novel dual-polarized patch antenna array with a hemispherical beam coverage is proposed in this article. The antenna array is composed of four symmetrically arranged units, and each one covers a fourth part of the hemispherical space independently. Two proximity-coupling feed baluns are adopted in the unit to produce dual-polarized radiations and enhance the operating bandwidth. A metal cavity beneath the radiating patch reduces the deterioration of the impedance matching caused by the fixture. An antenna array prototype is fabricated and measured for verification purpose. The measured results show that the gain is over 2 dBi within the whole hemispherical space in the frequency band of 4.5-5.1 GHz, while the VSWRs of all ports are below 2.