Interconnected Ground Plane Structure Based High Isolation, Dual Band Quad-Element MIMO Antenna for C-Band, and X-Band Applications

This paper presents a dual band orthogonal quad -element multiple input multiple output (MIMO) antenna for C -band and X -band applications. Each antenna element of the proposed MIMO antenna contains a deformed rectangle -shaped radiating patch etched with two circular slots of different radii on the top surface and partial ground plane in the bottom surface. The modified partial ground structure is used in the bottom to enhance the bandwidth of the antenna. The orthogonal arrangement of the proposed quad -element MIMO antenna is designed and fabricated with a distinct gap of d > A/2 between individual antenna elements. The interconnected ground plane was introduced in the bottom of the proposed quad -element MIMO antenna for high isolation. The proposed MIMO antenna has an overall size of 1.69A x 1.69A x 0.022A (at 4.23 GHz) and exhibits the measured double operating bands (S-11 < - 10 ) covering 4.23- 4.55 GHz and 6.30-10.22 GHz with the high isolation of > 27 dB and > 32 dB, respectively. Both the operating bands have simulated peak gain of 5.73 dBi and peak efficiency of 72% over the entire operating range. Furthermore, the presented antenna has good diversity performance with envelope correlation coefficient (ECC) < 0.001 , diversity gain (DG) of 9.996 dB, and total active reflection coefficient (TARC) < - 10 dB. The simulated and measured results of proposed MIMO antenna are in good agreement.