We provide state-of-the-art phase and amplitude noise measurements for signals from RF to optical frequencies.
The group provides high-precision measurement of electromagnetic signals in the radio-frequency, microwave and optical range. These measurements include phase noise, amplitude noise and perturbations due to vibration and temperature. Such precision measurements support high-value applications such as communications, remote sensing, radar, surveillance, GPS and atomic clocks. Another critical aspect of the group is to perform research that supports the improvement and fundamental understanding of noise metrology itself.
We identified a problem with cross-spectrum techniques that had been an accepted method of phase noise metrology for decades. Cross-spectral analysis is a mathematical tool for extracting the power spectral density of a correlated signal from two time series in the presence of uncorrelated interfering signals. We demonstrated and described a set of amplitude and phase conditions where the detection of the desired signal using cross-spectral analysis fails partially or entirely in the presence of a second uncorrelated signal. Not understanding how and when this effect occurs can lead to dramatic under-reporting of the desired signal. (See the pdf)