A Broadband Circularly Polarized Crossed Bowtie Antenna

Abstract

This work proposes a broadband circularly polarized probe fed printed crossed bowtie dipole antenna. The antenna contains bowtie radiators being placed in a cross configuration on both sides of the substrate and backed by a thick cylindrical cavity. The antenna possesses an impedance bandwidth of 55% (1.01-1.77 GHz) w.r.t -10 dB reflection coefficient and an axial ratio bandwidth of 35% (1.05-1.50 GHz) w.r.t 3 dB axial ratio. It exhibits Right Hand Circular Polarization (RHCP) with a unidirectional radiation pattern and a stable gain of 8.60 dBic, 8.86 dBic, and 9.41 dBic over the frequencies of 1.17 GHz, 1.22 GHz, and 1.38 GHz respectively. It has an overall antenna size of 0.48λo × 0.62λo × 0.21λo where λo is the free space wavelength at the lowest frequency. This simple, compact, low weight and highly efficient antenna is proposed for L-band applications.