Design of microstrip patch antennas with parasitic elements for minimized polarization mismatch

This paper proposes the design of microstrip patch antennas to minimize the polarization mismatch. The proposed antenna consists of a circular radiating patch and multiple parasitic elements. The number, length, and angular positions of the parasitic elements are adjusted to vary the antenna polarization as well as the orientation of the main axis. To demonstrate the feasibility, we design two sample antennas with different axial ratios and the orientation angles. The first sample antenna has linear polarization with a orientation angle of 0°, and the second sample antenna is elliptically polarized with a orientation angle of 5°. The results prove that the proposed antenna can adjust the polarization in the entire range of the axial ratio with the capability of rotating the orientation angle.