Corrugated horn antenna with perforated dielectric lens for radar-based level sensing in high-temperature, high-pressure environments

This study proposes a perforated dielectric lens integrated with a corrugated horn antenna specifically designed for radar-based level sensor applicable in high-temperature and high-pressure environments. The proposed horn lens antenna operates at 60 GHz, a frequency commonly used in the level-sensing radar industry. The proposed lens is fabricated from PTFE to ensure high thermal resistance and chemical stability for harsh industrial conditions. Its unit cell-based perforated structure is designed to provide two complementary benefits. First, the perforations enable airflow between the interior and exterior of the antenna, equalizing pressure and reducing mechanical stress on the lens in high-pressure environments. Second, by independently controlling the hole diameter and the unit-cell height, the lens provides effective phase compensation, converting the spherical wavefront at the horn aperture into a planar wave. To maximize the performance of the symmetric lens structure, a corrugated horn antenna that produces a symmetric beam pattern is designed. The proposed horn lens antenna achieves a measured gain of 29.07 dBi, representing a 3.26 dB improvement over the fabricated horn antenna through lens integration, with HPBWs of 6.9° and 6.7° in the E- and H-planes, respectively. Additionally, we conduct a radar measurement to verify the actual distance measurement performance of the designed horn lens antenna and confirm its durability under high-temperature and high-pressure conditions through simulation.