Design of an 8-Elements DGS based Dual Band MIMO Antenna with Improved Isolation for Wireless Communications

A dual band 8-elements MIMO (Multiple Input Multiple Output) antenna design is proposed in this paper. Microstrip patch and defected ground structure (DGS) have been incorporated to obtain two frequencies at 2.4 GHz (Wi-Fi) and 3.6 GHz (Wi-MAX) respectively. The values of gain at the resonant frequencies for proposed MIMO are achieved as 1.7 dB and 1.5 dB respectively. The total dimension of the 8-elements MIMO antenna is 0.992λ × 0.528λ (λ is wavelength in free-space calculated at lowest resonant frequency) which ensures that the overall 8-elements MIMO is very compact in size. The isolation between side-by-side antenna elements is improved by using T-shaped stubs thereby keeping the isolation values below -20 dB at the resonant frequencies. The values of envelop correlation coefficient (ECC) for all pair of antennas are less than 0.002 and diversity gain (DG) values are almost equal to 10 dB for overall bandwidth. The channel capacity loss (CCL) values at the resonating frequencies are nearly equal to 0.02. The proposed MIMO antenna is a good candidate in terms of scattering parameter, gain and diversity performances for practical wireless applications.