A compact dielectric resonator antenna with wideband circular polarization characteristics for C and X‐band applications

• Published in: Microwave and optical technology letters 2024-07, Vol.66 (7), p.n/a
• Main Authors: Harkare, Ankita H., Kothari, Ashwin G., Bhurane, Ankit A., Abegaonkar, Mahesh P., Patel, Pragati
• Format: Article
• Language: English
• Subjects: Antennas; Bandwidths; Broadband; Circular polarization; DRA; Frequencies; High gain; Impedance; Polarization characteristics; Radio antennas; Resonators; stacked; wideband
• ISSN: 0895-2477; 1098-2760
• DOI: 10.1002/mop.34241

A wideband circularly polarized (CP) stacked rectangular dielectric resonator antenna (RDRA) is proposed in this article. The 3 dB axial ratio (AR) and 10 dB impedance bandwidth overlap of more than 66% is obtained. For increased bandwidth, the antenna comprises two dielectric resonators separated by an air gap. The upper dielectric layer is rotated at ∠45∘ $\angle 4{5}^{\circ }$ relative to the lower layer to obtain orthogonal modes for CP Both layers have dielectric constant εr=9.8 ${\varepsilon }_{r}=9.8$. The rotation aids excitation of orthogonal modes TEδ11x∕TE1δ1y,TEδ31x∕TE3δ1y $T{E}_{\delta 11}^{x}\unicode{x02215}T{E}_{1\delta 1}^{y},T{E}_{\delta 31}^{x}\unicode{x02215}T{E}_{3\delta 1}^{y}$, and TEδ21x∕TE1δ2y $T{E}_{\delta 21}^{x}\unicode{x02215}T{E}_{1\delta 2}^{y}$ in RDRA. The higher‐order modes generate left‐hand circular polarization at frequencies 6.75, 7.8, and 10.7 GHz, respectively. The upper layer consists of three holes giving a 10 dB impedance bandwidth of 66.7% from 6.52 to 11.02 GHz. The CP gain of 8.7, 6.8, and 6.4 dBi for 6.75, 7.8, and 10.7 GHz, respectively, is measured. The conformal orthogonal feeds enable a 72% $ \% $ 3 dB AR bandwidth across the entire frequency band. The radiation efficiency is observed above 89% $ \% $ in the entire band (6.5–11 GHz). This work demonstrates a 66.7% $ \% $ overlap of 10 dB impedance and 3 dB AR bandwidth along with high gain in a single design which is suitable for 5G applications in C‐band as well as other X‐band applications.