Design of a Broadband Circularly-Polarized Lens Antenna with a Linearly Polarized Feeder

This paper presents a novel broadband thin lens antenna applied to circularly-polarized applications. The lens is composed of four identical novel conducting surfaces sandwiching three identical dielectric layers. The novel design is able to generate transmission phases of over 300. in two orthogonal directions separately, which can be applied to design lens antennas for applications of single, dual and circular polarizations. In addition, the design also includes advantages of a compact size, ease of fabricating and mounting, and a low cost. The numerical results demonstrate broad bandwidths of the 3-dB axial ratio and 1-dB gain, together with stable far-field radiation patterns.