Triple-Band Dual-Sense Circularly Polarized Hybrid Dielectric Resonator Antenna

In this paper, a triple-band dual-sense circularly polarized (CP) hybrid dielectric resonator antenna is proposed. A modified hexagonal dielectric resonator (DR) is top-loaded with a square microstrip ring (SMR). A vertical-tapered-strip connected to a 50- Ω microstrip line is used to excite the proposed antenna. It is found that the lower and central CP bands correspond to left-handed circular polarization and are produced by the TM 11 and TE 111 modes of the SMR and modified hexagonal DR, respectively. The upper CP band is formed by the combination of the quasi-TM 21 mode of the SMR and quasi-TE 111 mode of the DR that exhibits right-handed circular polarization. The measurement results of the fabricated prototype show triple-band response for |S 11 | < -10 dB with impedance bandwidths (IBWs) of 17.4% (1.75⁻2.03 GHz), 28.13% (2.23⁻2.96 GHz), and 2.97% (3.65⁻3.76 GHz) in the lower, central, and upper bands, respectively. The measured 3 dB axial ratio bandwidths lying within -10 dB IBWs are 3.69% (1.86⁻1.93 GHz), 5.46% (2.67⁻2.82 GHz), and 2.15% (3.68⁻3.76 GHz) along with the peak gains of 5 dBic, 5.28 dBic, and 2.36 dBic in the lower, central, and upper bands, respectively.