Surface-Wave Control Technique for Mutual Coupling Mitigation in Array Antenna
Amirhossein Askarian, Jianping Yao, Zhenguo Lü, Ke Wu
Abstract
We propose and investigate an easy technique to mitigate the mutual coupling of integrated antenna elements caused by surface waves in a high-permittivity grounded dielectric substrate, which can be deployed for high-density integration of antenna and front end on a substrate. Two approaches are examined to realize the proposed concept: 1) the removal of the ground plane between two collinear antennas and a series of uniform corrugations are introduced at the edges of the remaining parts to create a transition region between grounded and ungrounded regions and to form a sort of transversal surface waveguide and 2) to partially remove the ground plane with long, longitudinal, and closely spaced slots etched over the ground plane to offset the inductivity of the ground plane. Simulation and measurement results on an example based on two 25-GHz patch antennas show reductions in the mutual coupling of around 9 dB and improvement in broadside radiation pattern by 4 dBi.