A Low-profile Tri-Polarized Antenna in the S-Band

In this paper, a low-profile tri-polarized antenna is proposed, the VSWR of which is less than 2 in the frequency band of 2.35-2.5GHz. This design consists of a double-layer microstrip radiator and a top-loaded monopole, which can meet the requirements of wideband and low profile. This design yields 7.1% relative bandwidth for Z-polarization and 12.5% relative bandwidth for X-polarization and Y-polarization with $n$ profile, which has three independent ports for different polarizations. The beam of the antenna can cover the range of hemispheric-space when the three ports are excited. All parts of the antenna are fabricated by PCB process. The measured results are in good accordance with the simulations, thus validating its application potential in wideband and wide-angle scanning phased arrays which can be used in MIMO systems and radar systems.