Circularly Polarized Dielectric Rod Waveguide Antenna for Millimeter-Wave Applications

This paper presents a novel wideband circularly polarized dielectric rod waveguide (DRW) antenna for millimeter-wave applications. The rotated tapering rod that consists of a matching taper and a radiation taper is the first time adopted to realize circular polarization in the DRW antenna design. The circular polarization is realized by generating two orthogonal electric fields through rotating the radiation taper to an angle of \varphi relative to the matching taper. The proposed antenna achieves a wide impedance bandwidth throughout the whole Ka-band as well as a wide 3 dB axial ratio bandwidth (ARBW) of 37% from 27.5 to 40 GHz. The main advantages for this antenna design are its wide impedance bandwidth, 3 dB ARBW, simple structure, and easy fabrication.