Enhancement of Isolation in Dual-band Hemispherical DRA using DGS for MIMO Systems

A simple compact novel hemispherical DRA (HDRA) for isolation improvement with rectangular shaped slot Defected Ground Structure (DGS) is proposed. Length of the slot on the ground plane plays a vital role to enhance the isolation. An optimized length of the slot of b=4.5cm on PEC ground plane offers an isolation of -30dB and impedance bandwidth (S₁₁ <; - 10dB) of 15.6% with return loss -42.5dB at 2. 412GHz and - 23. 3dB isolation with -18dB return loss at 4. 216GHz. The proposed geometry resonates at two bands, primarily at ISM band and it is best suitable for Bluetooth, Wi-Fi, WiMax, WLAN and Satellite and radar applications in S-band.