Wideband Dual-Feed, Dual-Sense Circularly Polarized Dielectric Resonator Antenna

In this article, a wideband dual-feed, dual-sense circularly polarized (CP) dielectric resonator antenna (DRA) is proposed and demonstrated. An L-shaped slot and a vertical metal strip, fed by the same microstrip line, simultaneously excite the antenna. Using this feeding method, a dual-band, dual-sense CP triangular DRA is obtained by employing the DRA mode excited at the lower band and the hybrid mode excited at the upper band. Building on this initial design, a rotationally symmetric bowtie DRA (bDRA) consisting of two triangular dielectrics is proposed for wideband dual-sense CP operation. An additional excited slot mode widens impedance bandwidth and broadens the axial-ratio bandwidth (ARBW) of the lower band. Meanwhile, a higher order DRA mode excitation widens the ARBW of the higher band. The characteristics of these two DRAs are explored via simulation. Moreover, a bDRA prototype is fabricated and measured. The results demonstrate a directional antenna with a wide 10 dB return loss bandwidth of 63.7%, a broad 3 dB ARBW of 27.1% for the left-hand circular polarization, and a broad 3 dB ARBW of 12.8% for the right-hand circular polarization.