Measurement-Based Performance Comparison of Colocated Tripolarized Loop and Dipole Antennas

In this paper, a colocated tripolarized loop (TPL) antenna is proposed and a colocated tripolarized dipole (TPD) antenna is also designed for multiple-input multiple-output (MIMO) performance comparison. Both antennas have satisfactory performances of impedance bandwidth and isolation. The channel measurements are conducted in a nonlossy reverberation chamber (RC), a lossy RC, a corridor, and an office room. For both antennas, the measured average correlation coefficients (CCs) in the nonlossy RC are the smallest, close to 0.1, in the lossy RC are the largest, 0.3-0.5, and in the two indoor scenarios are slightly larger than that in the nonlossy RC. Except for the signal correlation, the relative path loss (RPL) should also be included to fairly compare the channel capacities. If the RPL is considered, a strong dependence of the channel capacity on the propagation properties can be seen. For both antennas, the channel capacities in the two indoor scenarios are 20%-30% smaller than that in the nonlossy RC. Interestingly, both antennas have similar condition numbers (CNs) in all the four scenarios, whose PDFs are close to that of the independent identically distributed (i.i.d.) complex Gaussian channel, which reveals that both antennas can obtain nearly three independent parallel subchannels and good multiplexing performance.