Bulk GaAs millimeter-wave detector with fast response

The properties of a bulk-effect millimeter-wave detector made from high-purity epitaxial GaAs are discussed. The devices are operated at 4.2°K in an unusual mode with DC bias above avalanche breakdown. When operated in this mode as a direct video detector, circuit-limited response time (10%-90% pulse) less than 20 nsec is observed, which is an order of magnitude faster than the response of bulk GaAs and InSb mixers. NEP values of less than 10^-10watts (D* on the order of 10¹⁰) in the video detector mode have been measured over the frequency range 10-70 GHz. The dependence of detector performance on operating parameters and frequency is given and compared with the predictions of hot-election theory developed for InSb detectors. Its performance is also compared with that of microwave-biased InSb, thermal, pyroelectric, and photoionized-impurity GaAs detectors and with point contact, Schottky barrier and MOM (tunneling) diodes, and is shown to provide significant advantages of either burnout resistance, risetime, or noise over all competitors in the millimeter spectral region.