Sensitive planar microwave diode on the base of ternary AlxGa1-xAs semiconductor compound

Abstract

The article presents results of experimental studies of dc and high frequency electrical character-istics of planar microwave diodes fabricated on the base of n-AlxGa1-xAs layer (x = 0, 0.15 or 0.3) epitaxially grown on semi-insulating GaAs substrate. The diodes can serve as reliable and inex-pensive sensors of microwave radiation in millimeter wavelength range, and sense electro-magnetic radiation directly without any external bias voltage at room temperature. Investiga-tion revealed strong dependence of the detection properties of the microwave diodes on AlAs mole fraction x: in the Ka microwave frequency range, the median value of voltage responsivity is several volts per watt in case of GaAs based diodes (x = 0), and it substantially increases reaching hundreds of volts per watt in case of higher x values. Also, a model enabling to forecast the responsivity of the sensor in other frequency ranges is proposed.