Miniaturized MIMO antenna design based on octagonal-shaped SRR metamaterial for UWB applications

A miniaturized antenna based on octagonal-shaped split ring resonator (O-SRR) metamaterial and CPW-feeder technique for ultra-wideband (UWB) applications is developed in this research. The structure of the component cell monopole antenna is designed by using a triangle-shaped fractal method and merging metamaterial implementation with the L-stub shape. These techniques provide a wide impedance bandwidth for the innovative wireless antenna, which operates from 2.46 to 13.98 GHz. The planned module cell dimensions are 20 by 16 square millimetres (0.164 lambda L x 0.131 ), where the wavelength (lambda L) is 121.95 mm. This low-profile antenna has then been employed to design an array of 2 x 2 Multi Input Multi Output (MIMO) antennas with an overall size of 20 x 34 mm2. Two symmetric antennas are arranged in the designed miniaturized MIMO system with an inverted T-shaped decoupling copper between them. Measurement results show that the dual antenna with multiple diversity metrics has great characteristics for MIMO applications due to providing low mutual coupling value, lower than 0.30 bits per s. /Hz of channel capacity loss, minor envelope correlation coefficient of fewer than 0.003, lower -10 dB of total active reflection coefficient, greater than 9.96 dB of diversity gain and proper mean effective gain (MEG ratio approximate to 1, MEG <= 0.5). A high peak gain magnitude of 5.71 dBi is provided at an operating frequency of 13.2 GHz for the recommended single antenna.