Analysis of Thermal and Shot Noise in Pumped Resistive Diodes

The process of frequency conversion and its applications are well known and are extensively treated in the literature. 1-22 This paper considers the special case of a resistive diode frequency converter. An important limitation on the minimum noise figure of such a frequency converter is imposed by the noise generated by the diode, and it is the main purpose of this paper to study the properties of this noise. Until a few years ago, much of the noise generated by the diode was 1// noise. Therefore, since very little was known about this type of noise, the early theories of frequency converters using positive resistance diodes paid little attention to the noise performance, and somewhat later theories accounted for noise only in a very approximate way. However, as the semiconductor craft has developed, 1// noise has been subject to considerable reduction and, even though its exact mechanism has not yet been completely established, in present diodes it appears to be important only at very low frequencies.23 Therefore, the study of shot and thermal noise in pumped diodes is of great practical importance. 1883