Measurements on power-conversion gain and noise ratio of the 1N26 crystal rectifiers

Abstract

Measurements have been performed on power conversion gain G and noise ratio n of a number of 1N26 silicon rectifiers (Sylvania Co., U.S.A.) using well-known techniques. The noise ratio has been investigated both with microwave excitation (10−6-10−3 W at 24 GHz) and with DC-excitation by currents up to 100 μA in the forward direction and up to 20 μA in the backward direction. The results (relative error 5–15 per cent, estimated absolute error 25–30 per cent for microwave excitation and about 15 per cent for DC-excitation) confirm the inverse-frequency dependence of n in the frequency region from 100 Hz-455 kHz and the independence of G ( 0.2 for sensitive rectifiers) of microwave power at powers higher than about 3.10−4 W. There is, however, a considerable discrepancy between the present results and the results of other investigators on G at powers below 3.10−4 W, and on power and DC-current dependence of n for microwave and DC-excitation, respectively. A possible explanation is suggested for the discrepancy of the power dependence of n. However, no explanation can be given of the saturation of n at DC-excitation by currents in the forward direction through sensitive rectifiers. No n-saturation was observed at microwave excitation.