Diversity performance of multiport dielectric resonator antennas

Single-structure dual and triple linearly polarised cylindrical dielectric resonator antennas (CDRAs) with respective excitation sets of two orthogonal modes and three degenerate modes at 120° to each other are investigated for operation as compact multiport antennas. The diversity performance of these multiport CDRAs is evaluated using theoretical expressions of envelope correlation coefficient, mean effective gain (MEG) and MEG ratio in conjunction with simulation and experimental S-parameter results. The multiport CDRAs portray low mutual coupling (<; -6.5 dB), different feed radiation pattern and polarisation directions, low envelope correlation coefficients (<;0.27) between feed points and near-equal branch MEG ratios (within ±1.8 dB). Thus, they satisfy the diversity performance benchmarks for application as compact multi-polarised diversity or multiple-input multiple-output antennas.