Isosceles Triangular Resonator Based Compact Triple Band Quad Element Multi Terminal Antenna

A triple band quad element multi-input-multi-output (MIMO) antenna is proposed for Bluetooth (2.4 GHz), WLAN (2.5/4.9 GHz) and LTE (3.7 GHz) applications. A compact triangular ring-shaped structure is used as an antenna element. An isosceles triangular ring resonator is designed in such a way that it offers dual-band and another ring resonator is placed inside the empty space of the first resonator to obtain the third band. The antenna element is studied in terms of S 11 and also the current distributions are observed at three resonance frequencies to find out the resonance mechanism. The proposed quad element MIMO antenna is compact in total area (0.45 lambda(0) x 0.45 lambda(0)). Isolation better than 20 dB is achieved with minimum inter-element spacing of 0.07 lambda(0) without extra isolation circuit. Gain, radiation patterns, envelope correlation coefficient (ECC), diversity gain (DG), channel capacity loss (CCL) and total active reflection coefficient (TARC) values are studied to comprehend the MIMO performance of the proposed design.