An Air-filled Cavity-backed Circularly Polarized Antenna based on Multilayered dielectric substrate

Abstract

An air-filled cavity-backed four-slot antenna for circular polarization is proposed in this paper. To reduce the resonant frequency, the n-shaped slot is utilized. The phase difference of 90 degree is achieved by controlling the length of the transmission line in the feeding network, and the air cavity is formed by hollowing the substrates. The simulated 10-dB frequency bandwidth is 17.62-18.61 GHz and the resonant frequency is 18.04 GHz. The antenna operates at right-hand circular polarization (RHCP) and the maximum antenna gain is 9.6 dBi at 18.3 GHz.