Imaging THz radar for security applications

Kurzfassung

Detection of concealed threats is a key issue in public security. In short range applications, passive imagers operating at millimetre wavelengths fulfill this task. However, for larger distances, they will suffer from limited spatial resolution. The paper describes the design and performance of 0.8-THz radar that will be capable to reveal concealed objects at a distance of more than 20 meter with a spatial resolution less than 1 cm. The radar highlights the scene with the built-in terahertz gas laser and uses heterodyne receiver with a single superconducting hot-electron bolometric mixer and a solid-state local oscillator. With integration time of 0.3 sec the receiver distinguishes a temperature difference of 2 K at the 20 m distance. The field of view is sampled with a high-speed conical scanner.