Millimeter and submillimeter wave receivers

This report reviews the current state-of-the-art performance figures for millimeter and submillimeter wave detectors and receiver systems. The frequency range under consideration is roughly 100 to 600 GHz. In contrast to the microwave (and optical) region where detectors perform close to the ideal limit, present millimeter and submillimeter wave detector sensitivities are one to two orders of magnitude away from the ideal. This situation does not represent any fundamental limitation but rather reflects technological problems in detector and source development peculiar to this region of the spectrum. At the present time, rapid technological progress is occurring as a consequence of (1) the demand from fields such as radio astronomy, fusion diagnostics, and high resolution radar, and (2) the breakthroughs in microelectronic techniques, ultra-high frequency solid-state sources, tubes, and lasers. These developments are reviewed and the implications for millimeter wave radar systems are discussed.