Design of a Ring Probe-Fed Metallic Cavity Antenna for Satellite Applications

This communication presents the design of a novel ring probe-fed metallic cavity antenna with circular polarization for satellite applications. The motivation for this work is to propose a novel design that has the advantage of electrically large size and improved 3-dB axial-ratio bandwidth in the Ku-band and other higher-frequency bands as well as low cost and easy fabrication. The resonant mode and circular polarization of the proposed antenna is excited by a ring probe. To verify the design concept, a brass C-band antenna prototype of the proposed antenna is fabricated and measured. The measured impedance bandwidth for |S11| ≤ -10 dB and 3-dB axial-ratio bandwidth are 1.08 GHz (6.94 GHz to 8.02 GHz) and 0.80 GHz (7.11 GHz to 7.91 GHz), respectively. The 3-dB axial-ratio bandwidth of the antenna is 10.7%. The measured gain is about 8.3 dBic across the whole 3-dB axial-ratio bandwidth. Very good consistency between the measurement and simulation for the return loss and radiation patterns is achieved.