Interaction Suppression Technique For High-Density Antenna Arrays For mm-Wave 5G MIMO Systems

This paper presents the feasibility study of applying a combination of suppression techniques to improve isolation between the radiation elements in high-density antenna arrays and thereby improve the arrays impedance bandwidth and radiation performance. High isolation between adjacent radiation elements was achieved by embedding a crisscrossed decoupling structure comprising slotted microstrip-lines and locating in the ground-plane under each slot a dielectric ring. The proposed periodic array behaves as artificial magnetic conductor (AMC) surfaces as incident waves in the substrate are fully reflected with a near zero degrees reflection phase. The proposed technique suppresses surface-wave propagation. Proof of concept was verified by applying the technique to a 2x4 linear array of triangular radiation patches designed to operate between 30-35 GHz. The array was implemented on a standard the Rogers RT 5880 substrate. Dimensions of the array are 40x20x0.8 mm(3). Measurement confirm improvement is the array's impedance bandwidth, fractional bandwidth, average isolation, radiation gain, and efficiency by 2 GHz, 6.15%, >10 dB, 6.6 dBi, and 29%. The array operates across 30-35GHz with average isolation between its radiation elements better than 23 dB, average gain and efficiency of 12 dBi and 85%, respectively. The technique can be applied to mm-Wave 5G MIMO systems.