Focusing choke ring antenna for a short-range millimeter-wave exposure system

An advanced feed for a mm-wave short-range exposure system is reported. The feed configuration is optimized to provide a highly-uniform illumination of biological samples positioned close to the antenna aperture. The prototype of the antenna is fabricated in metallized foam and measured. Its near-field characteristics are studied using the infrared imaging technique. The significant advantages of the reported choke ring antenna in terms of the enhanced exposure efficiency, improved exposure uniformity, and reduced exposure distance, are demonstrated via comparison with standard open-ended waveguide and horn antennas.