Wideband Two-Port Multiple-Input Multiple-Output Antenna in the C Band

A compact, two-element, wideband, multiple-input multiple-output (MIMO) antenna for applications in the 4.68 GHz to 6.62 GHz frequency range is presented here. The design consists of two identical, circular ring patch antennas. A hollow cylindrical substrate made of FR4 dielectric material is used for each antenna. The proposed two-port MIMO antenna is unique in its broad (1.94 GHz) frequency range of operation within the C band, along with its compact size of only 0.435 λ02 (λ0 corresponds to the free-space wavelength at 5 GHz). This wideband antenna is investigated and analysed using 3D electromagnetic software. Maximum directivity values ranging from 5.6 dBi to 7.4 dBi across the operating bandwidth range of 4.68 GHz to 6.62 GHz are obtained for this MIMO antenna. An envelope correlation coefficient less than 0.005 and a diversity gain of 10 dB are obtained within the operating frequency range. The ratio of the mean effective gain of the two antennas is found to be less than 0.8 dB for the entire range of operation. A channel capacity loss of less than 0.028 bits/s/Hz at 5 GHz and 0.041 bits/s/Hz at 6 GHz are obtained, respectively. The performance parameter values of the MIMO antenna system described here are compared with those of similar types of antennas presented in recently published papers.