Dual-Sense Circularly Polarized Waveguide Antenna Design Using Two Orthogonal Probes

This paper deals with a simple structure that achieves polarization sharing in a single waveguide-type circularly polarized antenna. In order to excite circular polarization, the cross-section of the waveguide is square so that <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{TE}_{10}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{TE}_{01}$</tex> can be degenerate. In order to feed, two probes are arranged orthogonally within the cross-section of the waveguide, and a structure to avoid the unwanted coupling between them is instralled Moreover, the coupling between the two ports is also discussed. Furthermore, since the waveguide is likely to have a broadband characteristic, the bandwidth of this antenna is described.