Paper Title
Design and Analysis of Mutual Coupling Reduction Techniques in an Antenna Arrays

Abstract
This paper design two-element and four-element mimo without stub. The2.45GHz ISM bands are used by the developed antenna, which employs a pentagon microstrip patch antenna.This mimo antenna was simulated in HFSS Software and has a 4-element mimo dimension of 120x120x1.6mm and a 2-element mimo dimension of 120x60x1.6mm.The reflection coefficient magnitude of the 2x2 mimo antenna are S11,S22,S33 and S44 is-10dB. The 2x2 mimo antenna with a-15dB return loss, the maximum isolation of S21, S31, S41 is -45dB has been achieved using unique combination of an inverted ground plan structure and a stub to reduce mutual coupling. Two antennas should be spaced apart to avoid mutual interaction. We compare the results of varying the distance between the antennas by 0.25λ, 0.5λ andstudy the mimo antennas specification as well. In thus, we study diversity and envelop correlation coefficient. Keywords - MIMO Antenna, Pentagon Microstrip Patch Antenna, Stub, Mutual Coupling, Envelop Correlation Coefficient, Diversity