Analysis of Circular Polarization of Cylindrically Bent Microstrip Antennas

الملخص EN

When circularly polarized (CP) microstrip antennas are bent, the polarization becomes elliptical.

We present a simple model that describes the phenomenon.

The two linear modes present in a CP patch are modeled separately and added together to produce CP.

Bending distorts the almost-spherical equiphase surface of a linearly polarized patch, which leads to phase imbalance in the far-field of a CP patch.

The model predicts both the frequency shifting of the axial ratio band as well as the narrowing of the axial ratio beam.

Uncontrolled bending is a problem associated especially with flexible textile antennas, and wearable antennas should therefore be designed somewhat conformal.