Uncertainty Evaluation of $-$ 100-dBc/Hz Flat Phase Noise Standard at 10 MHz

We describe an uncertainty evaluation of the -100-dBc/Hz flat phase noise standard at 10 MHz, which ensures traceability to the International System of Units. The flat phase noise standard signal is produced using a carrier combined with white noise. To ensure traceability, both the flat phase noise signal power and the power spectral density of the white noise are determined with a calibrated power meter and a noise standard, respectively. Sources of uncertainties in the system are discussed, and the overall expanded uncertainty is found to be 0.6 dB for a Fourier frequency of 1 Hz, 0.26 dB for 10 Hz, and 0.22 dB for 1, 10, and 100 kHz. We also report on the validity of a flat phase noise standard that consists of high-power white noise.