Wideband Circularly Polarized Cavity-Backed Asymmetric Crossed Bowtie Dipole Antenna

• Published in: IEEE antennas and wireless propagation letters Vol. 15; pp. 358 - 361
• Main Authors: Tran, Huy Hung, Park, Ikmo
• Format: Journal Article
• Language: English
• Published: New York IEEE 2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antenna measurements; Antennas; Asymmetric bowtie; Asymmetry; Bandwidth; Broadband; Broadband antennas; Circularity; circularly polarized; crossed dipole; Dipole antennas; Gain; Impedance; single-feed; Slot antennas; Wideband
• ISSN: 1536-1225; 1548-5757
• DOI: 10.1109/LAWP.2015.2445939

A single-feed, cavity-backed, circularly polarized (CP) antenna is designed for wideband wireless applications. The antenna is made up of asymmetric crossed bowtie dipoles and achieves broadband characteristics in terms of impedance and 3-dB axial-ratio (AR) bandwidths. A double vacant-quarter printed ring with orthogonal asymmetric bowties is employed for CP radiation and then combined with slot-mode radiation to significantly enhance the CP operation bandwidth. Measurements of an optimized antenna prototype with an overall size of 0.88λ o × 0.88λ o × 0.23λ o at 2.4 GHz show that it can yield an impedance bandwidth of approximately 57% and a 3-dB AR bandwidth of approximately 51%. In addition, a unidirectional CP radiation pattern with a high broadside average gain of 9.6 dBic was achieved across the operating bandwidth.