Wideband Circularly Polarized 3-D Printed Dielectric Rod Antenna

This article presents a 3-D-printed dielectric rod antenna with wideband circular polarization. The proposed dielectric device comprises two main components: a launching part and a radiating part. The launching part consists of three cylindrical sections with stepped permittivity for wideband impedance matching to the rectangular waveguide feed. The radiating part is a tapered dielectric rod with two helical grooves that generate circular polarization. The experimental results verify that the proposed antenna exhibits a wide impedance bandwidth of 60.3% from 4.05 to 7.55 GHz, a wide 3 dB axial ratio bandwidth of 57.0% from 4.20 to 7.55 GHz, a high realized gain varying within 8.3 and 11.5 dBiC over the whole band, and the desired stable endfire radiation patterns. The 3-D printing technology provides a viable approach to realization of the proposed complicated geometry in a single piece with high accuracy and great flexibility.