Diversity performance of a dual-linear polarisation suspended gap-coupled microstrip antenna
The diversity performance of a dual-linear polarisation microstrip antenna is investigated across the broad operating bandwidth. As an example, the suspended gap-coupled microstrip antenna has been chosen for the study. Using a ±45° polarisation scheme, the probe-fed square main patch, surrounded by four parasitic patches on its radiating and non-radiating sides, is suspended above the ground plane. The simulated and measured impedance as well as the radiation performance are given. The diversity performance is evaluated in terms of the far-field coupling, output power correlation as well as the diversity gain in a non-fading channel. From the analysis performed at three primary frequencies, the diversity performance has been found to vary across the impedance bandwidth. It is shown that other than the environment, the radiation characteristics of the antenna have a considerable effect on the diversity gain.
