Analysis of cross-shaped dual-polarized microstrip patch antennas

Dual linear polarization with low cross polarization and high isolation is achieved by cross shaped microstrip patch antennas. The segmentation method along with multiport network theory is used to predict the antenna characteristics such as resonant frequency, input impedance, scattering parameters, and radiation patterns. The theoretical and experimental results are in very good agreement with each other and show significant improvement of the cross polarization performance and the isolation between the input ports. It is shown that the cross polarization level is reduced by 10 to 20 dB, and isolation between the input ports is increased by 5 to 10 dB compared to the conventional dual-polarized rectangular microstrip patches.