INVESTIGATION OF GAAS SCHOTTKY-BARRIER DIODES IN THE THZ RANGE

The properties of GaAs Schottky barrier diodes as video detectors and mixing elements were investigated in the frequency range from 0.8-2.5 THz. For the most sensitive diode, the video responsivity and system noise temperature were measured as a function of incident laser power. The highest video responsivity was 2,000 V/W at 214μm and 60 V/W at 118μm. For five diodes differing in doping, capacitance, series resistance and anode diameter, the system noise temperature was measured at 214μm and 118μm. The best single sideband (SSB) values are 12,300 K and 24,200 K at 214μm and 118μm, respectively. The system noise temperature versus frequency is given over the range from 0.5-3 THz for two specific diodes demonstrating that the sharpness of the I-V characteristics is only of secondary importance for mixer perfomance at such high frequencies. © 1990 Plenum Publishing Corporation.