The oscillating, or repeating, signal that is the basis for constructing all signals is a voltage that exactly follows simple periodic sine and cosine functions of time. The synthesis of such signals, using an oscillator coupled with a "frequency synthesizer," can never be perfectly realized because the voltages from these devices are perturbed by random noise from real electronic components.
Frequency synthesis plays a role in virtually all present-day commercial, industrial, and military technologies. State-of-the-art low-noise frequency synthesis is a particularly important technical asset to high-speed telecommunications, efficient management of the wireless spectrum, and high-resolution imaging. It is worth noting that overall performance of various technologies depends on, and is often limited by, phase and amplitude noise fluctuations in oscillators and frequency synthesizers.
NIST's Time and Frequency Metrology Group activities include:
The Time and Frequency Metrology Group is engaging in new programs in spectrum analysis and calibration services for industrial, military, and commercial organizations. PM /AM noise measurements require traceability and certification of microwave components such as oscillators, amplifiers, etc. The following calibration services are provided by the group:
PM/AM Noise Measurement Systems