Novel dual polarized array antennas for 60GHz mmWPAN applications

Recent years, more and more intensive researches have been done widely for the application of high speed, short distance millimeter wave wireless personal area network (mmWPAN) in the unlicensed frequency band of 60GHz [1, 2]. An antenna with high gain (more than 10dBi) is expected in such a system to provide enough link budgets and compensate high propagation loss. Most of the researches were focused on the linear polarization antennas so far. The works have been published for millimeter wave antennas are including: an ultra-wide band patch stacked antenna which can cover all frequencies required by USA, Japan and EU [3], multi-section switched antenna [4], phased arrays with millimeter-integrated circuits [5] and circular polarization antenna [6]. However, to authors' knowledge, few works have been done for polarization diversity antenna, which actually is an important issue in mobile/portable wireless communication system, where the antenna polarization varies with time and spaces. A serious polarization mismatching will cause serious power loss in the transmission link. In this paper, a novel tree-shaped patch antenna array with two orthogonal polarizations is proposed and implemented by means of simple and compact feeding network.