A waveguide-fed grid E-band array antenna

In this paper, the design and simulation of an E-band grid array antenna is presented. The antenna is fed using a waveguide to improve its efficiency. This antenna is designed for 80 GHz radio application, and a low cost FR-4 printed circuit board (εr=4.3) is used. The traditional grid array antenna is fed using coaxial cables. However, at such high frequencies, the size of the coaxial feed is small, and therefore high cost and difficult to fabrication. Moreover, the attenuation of an electromagnetic wave due to the coaxial is significant. Thus, in this design, a WR-10 waveguide is used to feed the grid array antenna at the back of the ground plane. This feed design improves the efficiency and realized gain of the antenna significantly. The resulting gain can be as high as 8.34 dBi, up from 6.25 dBi for the coaxial feed.