Noise Spectrum Measurements from 10 Hz to 1 MHz using a Tunable Switching Radiometer. I. Instrumentation

Abstract

The first application of a switching (Dicke) radiometer to high-precision, noise spectrum measurements from 10 Hz to 1 MHz is described. The solution of the instrumentation problems unique to this frequency range are discussed in detail. The advantage of this radiometer is that it can be employed in a null mode so that it is direct reading and the measurement precision at all frequencies is limited fundamentally by the bandwidth and averaging time or by the calibration of the reference noise source and its attenuator.