Abstract :
The various kinds of noise fluctuation which occur in silicon microwave diodes are discussed in the light of measurements at widely differing frequencies of the noise produced when the diodes are excited by d.c. bias. It is found that flicker noise which is dominant at 1 600 c/s may extend to 45 Mc/s and beyond. By selecting diodes for low noise output and restricting the measurements to low bias currents, good agreement is found at 45 Mc/s with the calculated values of shot noise; it is established, in particular, that the thermal noise which occurs for zero bias may be calculated in terms of the shot-noise concept. In the region of 30 000¿40 000 Mc/s the noise produced by reverse bias is probably attributable entirely to shot noise. Finally the bearing of these measurements on the problem of noise during mixer operation is discussed briefly.
