Isolation enhancement technique in a dual-band THz MIMO antenna with single radiator

A technique is implemented for the enhancement of isolation between the ports in terahertz multi-input-multi-output (MIMO) antenna. A rectangular metallic patch is utilized for developing the two-port dual-band THz antenna. The radiator is perturbed with six elliptical slots and a square slot at the center achieve the peak/average value of the isolation 22.16/20.12 in the lower and 18.65/18.24 in the upper band. The non-resonant graphene sheet is placed in the square slot to obtain tunability in the isolation plot. The inclusion of graphene material alters the fringing-field in the cavity of the radiating patch allowing the antenna response to be tuned with input ports and improve the peak/average isolation as 34.66/35.12 in the lower and 25.44/27.45 in the upper band. Electrical circuit containing two tank circuits is developed to validate the resonances obtained in the antenna equivalent to two operating higher modes. Antenna provides the peak gain of 6.87 dBi and 7.27 dBi at 4.93 and 5.43 THz, respectively along with the efficiency of more than 88.7%.