Mutual coupling reduction in orthogonally fed aperture-coupled patch antennas via an integrated metasurface

Abstract

An aperture-coupled rectangular microstrip patch antenna fed by an orthogonal substrate integrated waveguide (SIW) feed line is of high interest for one-sided imaging systems. This type of feeding technique is beneficial for 2D imaging array configurations in millimeter wave imaging systems due to the limited availability of space for compact array design. In order to reduce the coupling between two adjacent patches (which deteriorates the quality of the imaging results), an artificial impedance metasurface can be used. When properly designed for this purpose, the imaging frequency corresponds to the bandgap frequency of the metasurface. In this paper, a metasurface integrated with this new type of feeding technique is presented. The improved structure shows a 20 dB reduction in coupling (|S 21 |) between two adjacent antennas separated by a spacing of one wavelength at an imaging frequency of 30 GHz.