Broadband high-gain 60 GHz antenna array

Abstract

The design, fabrication and characterization of a 2×8 patch antenna array operating in the IEEE 802.11ad frequency band (57-66 GHz) is presented. The design is based on two-layer structures, where the radiating patches placed on top substrate are fed by conductor backed coplanar waveguide (CPW)-fed loop slots, which are placed on the bottom substrate. The top layer is formed by using a low-cost pyrex (ϵr = 4.9, tani = 0.01) substrate of 500μm thickness. The pyrex is then etched away to a thickness of 100μm, where 400μm of air volume is formed underneath. This approach does not only benefit from the low-cost feature of pyrex but also exploits the low-loss nature of air. The thin layer of pyrex is solely used for mechanical support for the radiating patches while the air provides good RF-environment for the array. The bottom substrate housing the CPW feed network is an RF-compatible and microfabrication friendly quartz (ϵr = 3.9, tanδ = 0.0002) of 525μm thickness. The simulations indicate a good maximum realized gain of 19.3 dBi of which variation over ∼ 17% bandwidth is relatively constant changing from 17-19.3 dBi. © 2016 IEEE.