Exponentially curved aperture antenna for broadband circular polarization operation

An exponentially curved aperture antenna for broadband circular polarization (CP) operation is presented. The design uses equiangular curves as the edges of the aperture shape. A prototype of the proposed antenna was implemented and measured. The CP radiation is obtained from the leakage of the traveling-wave propagating along the edge of the equiangular curve. The 3 dB axial ratio (AR) bandwidth achieves up to 49%. The experimental results are in good agreement with the simulation.