IEEE Transactions on Microwave Theory and Techniques · 1987 · 54 citations · 25 references
EngineeringElectrical EngineeringMicroelectronicsMicrowave EngineeringSemiconductor DevicesHigh-frequency Semiconductor DevicesMicrowave Integrated CircuitsMicrowave MixersMicrowave Semiconductor DevicesNoise In Electronic DevicesNoise In Semiconductor DevicesCorrelation MatrixDiode MixersJunction CapacitanceMixersMixers Noise AnalysisParasitic CapacitanceParasitic ElementsSeries Resistance
An analysis of the noise of millimeter‑ and sub‑millimeter‑wavelength GaAs Schottky mixer diodes is presented and used to evaluate the optimization of cryogenic mixer diodes. The analysis accounts for the correlation of the downconverted components of the time‑varying hot‑electron noise in the series resistance, enabling accurate modeling even for cryogenically cooled mixers at sub‑millimeter wavelengths. The study shows that the series‑resistance noise correlation matrix depends on the Fourier coefficients of the squared diode current rather than the square of the Fourier coefficients, and that minimizing the diode’s I‑V slope parameter V₀ is more critical than reducing parasitic elements for millimeter‑wavelength operation, while at frequencies above 600 GHz the junction capacitance dominates; experimental results from multiple groups support these conclusions.
An analysis of the noise of millimeter- and submillimeter-wavelength mixers with GaAs Schottky diodes is presented. This analysis accounts for the correlation of the downconverted components of the time-varying hot-electron noise in the series resistance, and is thus accurate even for cryogenically cooled mixers operated at submillimeter wavelengths. This paper shows that the terms of the series-resistance noise correlation matrix are functions of the Fourier coefficients of the squared diode current F(I/sup 2/) rather than the square of the Fourier coefficients of the diode current [F(I)]/sup 2/, as has been previously presented in the literature. The analysis is used to evaluate the optimization of cryogenic mixer diodes. It is shown that minimization of the diode's I-V slope parameter V/sub 0/ is more critical than reduction of the parasitic elements for millimeter-wavelength operation, while at frequencies above 600 GHz (Lambda<0.5 mm), the junction capacitance is the most crucial parameter. Experimental results from several research groups working with a variety of mixers are presented to substantiate these results.
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