H11 wave radiation from a circular waveguide with spiral in waveguide aperture

The radiation of circularly polarized fields is of interest due to its particular properties which are promising for communication systems, antenna arrays, medical equipment, etc. As the H₁₁ mode radiation from a circular waveguide is linearly polarized and owing to the circularly polarized radiation of a planar logarithmic spiral, placing the latter in the waveguide aperture is expected to improve the polarization characteristics of radiation. That is why we investigate the radiation of a circular waveguide with a planar spiral in the waveguide aperture. We investigate for the first time the radiation properties of a circular waveguide with a spiral in its aperture using the mode matching method