Analysis and Reduction of Mutual Coupling in a Microstrip Array With a Magneto-Electric Structure

Abstract

This article provided a detailed analysis of the mutual coupling phenomena in the microstrip patch array and introduced a novel compact magnetoelectric structure as a planar decoupling element. The proposed decoupling structure, termed as the interconnected array of semicircularly slotted structure, was formed as a combination of the electric dipole, magnetic dipoles, and circular patches. This compact magnetoelectric structure improves the isolation between two patches by around 9 dB at the resonating frequency of the radiating antennas with the edge-to-edge spacing of only 0.057 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\lambda _0$</tex-math></inline-formula> . This planar design is spatially compact and can maintain the broadside radiation characteristics. The decoupling mechanisms were analyzed in terms the equivalent port transmission coefficients and the parasitically induced surface current density vector. A design method had been proposed along with an equivalent circuit representation of the of the band-notch structure. The fabricated structure was found to show good matching between the measured and simulated results.