COMPACT TWO-PORT MIMO ANTENNA WITH HIGH ISOLATION USING PARASITIC REFLECTORS FOR UWB, X AND KU BAND APPLICATIONS

In this communication, a compact two-port multiple input multiple output (MIMO) antenna with high isolation is presented for multiband applications. The size of the proposed structure is 0.15λ0 ×0.27λ0 (λ0, measured at lower frequency, is 2.95 GHz), and the antenna elements are separated by a distance of 0.04λ0. The truncated partial ground offers good impedance performance with a fractional bandwidth of 136.5% from 2.95 to 15.65 GHz and covers the uninterrupted ultra-wideband (UWB), X and Ku band applications. High isolation of more than 25 dB is attained by placing parasitic elements between the antennas in a precise manner. The proposed structure is simulated, fabricated, tested, and verified practically. The radiation efficiency is more than 90% of the entire band. The peak gain values vary from 1.2 to 6.8 dB in the desired band, and its maximum value is 6.8 dB at 11.6 GHz. Diversity performance is also studied. The proposed structure offers an envelope correlation coefficient (ECC) of less than 0.04, diversity gain (DG) of greater than 9.996 dB, total active reflection coefficient (TARC) of below −10 dB, mean effective gain (MEG) of around −3 dB, and channel capacity losses (CCL) values are below 0.2 bits/sec/Hz. The measured and simulation results are in good concord.