Shot Noise in p-n Junction Frequency Converters*

Abstract

General equations are derived for the noise figure of a frequency converter using a p-n junction diode with arbitrary minority-carrier storage. A p-n junction with a purely capacitive nonlinear admittance permits, theoretically, noiseless amplification. Structures are suggested for approximating this ideal. A diffused silicon junction diode gave 9 db of gain with a 2-db noise figure in converting 460 to 9375 mc and gave a 3-db noise figure as a 6000-mc negative-resistance amplifier. Nonlinear-resistance diodes cannot amplify but can give low-noise frequency conversion if the local-oscillator drive produces a sharply pulsed current waveform in the diode.