A Compact UWB Wide Beam High-Temperature Resistant Open-Ended Waveguide Antenna at X-band

In this paper, a compact ultra-wideband (UWB) high-temperature resistant open-ended waveguide antenna at X-band is designed with wide beam performance. The open-ended waveguide antenna with a large metal flange is placed under the thermal insulation material which is packaged by the thermal protection shield. Meanwhile, the metal flange effectively reduces the side and back lobes of the antenna. Impedance matching is improved by adding a tuning post. Realized gain of the high-temperature resistant antenna reaches more than -1dB within ±50°, and an impedance bandwidth for VSWR $\leq$ 2.0 from 7.5 to 12GHz is covered. Under the continuous time of 2000s and surface heat source temperature of 1200°, the feed port temperature can be kept below 135°.