Designs for achiving dual-polarization radiation with high isolation between two feeding ports as well as wide bandwidth have been an important subject in patch antenna design.
In this paper, the design of a dual-polarization rectangular microstrip patch antenna excited by using both an aperture-coupled feed (port1) and a 3-dimentional microstrip feed (port2) is presented.
The antenna characteristics such as the resonant frequency, input impedance, radiation pattern and return loss as function of parameters of two feed lines are simulated by using the commercial software IE3D.
The parameter studies using IE3D provide enough design data. A 60mm×50mm rectangular patch at a distance 22mm above the ground plane of a grounded substrate of thickness 0.81mm and relative permittivity 3.38 is fabricated.
Both measured impedance bandwidths for the two orthogonal polarizations are greater than 17% and the measured isolation between the two feeding ports can be less than -30dB for the entire bandwidth of IMT-2000. The antenna gains of 7.8dBi and 7.4dBi in the broadside direction fed by port1 and port2, respectively, were calculated.