Compact Wearable UWB MIMO Antenna with Reduced Mutual Coupling and Notch Characteristics of WLAN Band

A new compact low-profile multiple-input multiple-output (MIMO) antenna with slotted stub and defected ground structure (DGS) is presented for wearable applications. Two star-shaped elements made of thin copper film are fastened on a jeans substrate to develop the antenna. It operates in the frequency of 3.35-4.12 GHz and 6.07-11.67 GHz. The antenna offers notch characteristics for the full WLAN (2.4-2.485 and 5.15-5.825 GHz) band covering the ultra-wide band. Excellent port isolation of exceeding 20.3 dB is achieved throughout the operating band due to the functioning of integrated stub and DGS on the back layer of the antenna. The evaluated envelope correlation coefficient (ECC) between the antenna elements is below 0.2, whereas diversity gain is above 9.8 dB. Other diversity parameters like mean effective gain (MEG = +/- 0.02 dB) and channel capacity loss (CCL < 0.25 BPS/Hz) are very suitable for MIMO operations. The antenna provides good on-body performances. The specific absorption rate (SAR) is investigated and found good enough when it is integrated with a suitable decoupling network. The performance of the suggested antenna by both simulation and measurement designates a good contestant for WLAN notch UWB applications.