A Broadband Leaky-wave Aperture Antenna of Circular Polarization

This paper presents a novel circularly polarized (CP) aperture antenna with a hybrid modes of traveling wave and resonant wave. The antenna comprises a circular aperture with fan-shaped perturbation and a straight microstrip line for the antenna feed. Containing the inherent feature in traveling wave antennas, the presented antenna performs very wideband results, including a 10-dB return loss bandwidth of 57%, a 6-dB axial ratio (AR) bandwidth of 55%, and a 3-dB gain drop bandwidth of 55% measured at broadside. The presented antenna is printed on a PCB substrate for low manufacturing cost. We built a prototype for the presented antenna. A good agreement between simulation and measurement is achieved.