Improving the input characteristics of a circularly polarized proximity-fed microstrip antenna with polarization switching ability

A technique to improve the input characteristics of a circularly polarized proximity-fed microstrip antenna (CP-PMA) that can be used in applications requiring polarization diversity is presented in this paper. This technique provides improved return loss without affecting other characteristics of the antenna such as axial ratios and radiation patterns. A good agreement between the simulated and measured results was obtained, thus confirming the effective performances of the proposed configurations.