Design and application of high-power cavity-backed helical antenna with unit ceramic radome

A high-power cavity-backed helical antenna with a unit ceramic radome is proposed and investigated for the first time. The helical antenna uses a unit ceramic radome to realise a vacuum seal for a single-element antenna, and the radome is designed in a thin-wall structure to maintain low insertion loss. The proposed antenna uses a backed cavity in a cylindrical structure to reduce the mutual coupling among elements. An S-band antenna prototype with a centre frequency of 2.856 GHz is designed and optimised. The performance of the antenna is simulated, including radiation performances and the power-handling capacity. This antenna is applied in an S-band 16-element sub-array and a 256-element array antenna. The experiment results validate that this antenna can realise favourable circularly polarised radiation in its axial direction in the frequency range of 2.7-3.0 GHz, and the average power-handling capacity for a single-element antenna is at least ~4.7 MW.