Dual Circular-Polarized SIW-Fed High-Gain Scalable Antenna Array for 60 GHz Applications

In this paper, a dual circularly polarized high-gain scalable antenna array is proposed for the 60 GHz applications. The array consists of cross-slot-coupled cavity-backed square patch antenna elements fed by a novel substrate-integrated waveguide network. In our design, the two polarizations share the common radiating element and feed network so that they exhibit similar performance in terms of bandwidth, gain, and radiation patterns for both polarizations. An 8x8 element array is designed to demonstrate its function, and the simulated data exhibit an overlapped bandwidth (SWR < 2, 3 dB down gain bandwidth and AR < 3 dB) of approximately 23%, a gain up to 25.8 dBic for both ports, and a port-to-Port isolation larger than 14 dB. Good unidirectional and symmetrical radiation patterns are observed. A prototype is fabricated, and the measured results agree with the simulated ones with acceptable disparities. The reported structure is built by the conventional printed circuit board technology which is cost effective. With these advantages, the proposed scalable antenna design is a good candidate for millimeter-wave wireless communications.