A Topology-Based Miniaturization of Circularly Polarized Patch Antennas

A novel approach for the miniaturization of circularly polarized patch antennas is presented. This enables a size reduction of as high as 75%, compared to a conventional corner-truncated circularly polarized patch antenna. The proposed design procedure consists of a number of intermediate steps, each of which produces antenna miniaturization as well as the desired polarization and impedance matching properties. This is very challenging in miniaturizing circularly polarized probe-fed patch antennas. It is shown that two resonant frequencies can be tuned independently to produce a dual band antenna with two orthogonal polarizations. Finally, two circularly polarized miniaturized patch antennas with different miniaturization factors are fabricated, and their input impedances, radiation patterns and axial ratios are discussed.