The super-Schottky microwave mixer

The super-Schottky diode has now achieved the lowest reported NEP and mixer noise temperature at X-band: 5×10
^-16
W/Hz
^1/2
and 6 K, respectively at an operating temperature of 1.1 K. Diode fabrication, mixer construction, and extensive microwave performance measurements as a function of such operating parameters as temperature, LO power, and dc bias are reported. Extension to millimeter wavelengths requires further reduction in parasitic losses while retaining the low impedance nonlinearity from the superconductive single particle tunneling. Material and geometric design parameters are discussed and applied to the III-V semiconductors. A comparison of experimental results for GaAs with theory and the near term potential is discussed.