Compact Pattern Diversity Antenna with 3-D Printed All-dielectric Superstrate for WLAN Access Points

This paper presents a four-port pattern diversity antenna with a 3-D printed all-dielectric superstrate for 5.2 GHz Wireless Local Area Network (WLAN) access points. The topology of four-port coaxial-fed circular patch antennas provides a beam tilt of +/- 45 degrees and +/- 15 degrees with an angular coverage of +/- 60 degrees. The beam tilt is obtained through this unique topology, without the need for any additional phase shifting circuits. Then, a low-cost 3-D printed dielectric superstrate is designed to enhance and equalize the gain without compromising on the beam tilt and polarization purity of the antennas. The antenna module has an impedance bandwidth of 80 MHz (5.16 GHz-5.24 GHz), covering the IEEE 802.11ac band, for a gain of 9 dBi throughout the band and across the ports. The dielectric superstrate provides a gain enhancement of 3.8 dB for antennas 1 and 4, and 5.4 dB gain enhancement for antennas 2 and 3, respectively.