An SWB MIMO Antenna with Dual Band Rejection and Polarization Diversity for Ultra-Wide Band Applications

This paper presents a super-wide band 2-element multi-input multi-output antenna with dual band-rejection specifications and high isolation proposed for use in broadband polarization diversity communication systems. The total dimensions of the fabricated antenna are 34 x 60 mm(2) and achieve a super-wide impedance matching of more than 15 GHz from 2.3 to 18 GHz due to the simulated and measured results which cover L, S, C, X, Ku bands and some parts of K band with two notched frequency bands around 3.1-3.7 GHz for WiMAX and 5.1-5.8 GHz for WLAN which realized by etching two half-wavelength elliptic single complementary split-ring resonators of different dimensions on the radiating patches. This proposed antenna comprises two identical elements placed orthogonally to each other and fed by two 50 omega coplanar waveguide lines; therefore, isolation of more than 20 dB is obtained autonomously without utilizing any other special technique. Diversity performance in terms of envelop correlation coefficient (ECC < 0.0035), multiplexing efficiency (eta(mux )> - 1 dB) and diversity gain (DG > 9.99 dB) is also calculated, showing satisfactory MIMO characteristics.