RADIOFREQUENCY AND MICROWAVE NOISE METROLOGY

摘要

The radiofrequency interferometer, as compared to other methods for the measurement of amplitude noise and phase noise, shows higher sensitivity. In fa-vorble onditions the background noise can be as low as ―180 dB[rad~2]/Hz at f = 1 Hz off the carrier, up to microwaves (10 GHz) for real-time measurements. Exploiting correlation and averaging, a white noise floor of —204 dB[rad~2]/Hz has been observed, not limited by the thermal energy k_BT_0 referred to the carroer power P_0. This article reports on the method, on the recent developments, and on the measurement of low-noise hard-to-measure devices.