Design and Implementation of a Compact 6-Port Antenna

A pair of half-wavelength slot and narrow patch antennas stacked closely together to form a set of nearly colocated antennas for achieving polarization diversity is described. A reduced-size version is then proposed by utilizing a quarter-wavelength slot and planar inverted-F antenna (PIFA) pair, respectively. When three sets of these antennas are placed on each orthogonal axis, a compact 6-port antenna is constructed. Key characteristics of the antennas are found through electromagnetic simulation and physical measurements.