Fasesviktstøy

Fasesviktstøy, also known as phase noise, is a type of signal distortion that occurs in electronic oscillators and signal sources. It is characterized by rapid, short-term fluctuations in the phase of a signal. These fluctuations are random in nature and arise from various noise sources within the oscillator circuitry, such as thermal noise and flicker noise.

Phase noise is typically measured in decibels per Hertz (dBc/Hz) relative to the carrier frequency. A lower phase noise value indicates a cleaner signal with less jitter. The presence of phase noise can degrade the performance of communication systems, radar systems, and measurement equipment. In digital communications, excessive phase noise can lead to bit errors, while in radio receivers, it can reduce sensitivity and selectivity.

Common sources of phase noise include the active devices in an oscillator (e.g., transistors or vacuum tubes), passive components like capacitors and inductors, and power supply noise. The design of the oscillator circuit plays a crucial role in minimizing phase noise. Techniques such as using low-noise components, optimizing the Q-factor of resonant circuits, and employing feedback mechanisms can help to suppress phase noise.

Characterizing phase noise often involves using specialized spectrum analyzers or phase noise test sets. These instruments can measure the spectral impurity introduced by the phase fluctuations. Understanding and mitigating phase noise is essential for achieving high-performance signal generation and processing in a wide range of electronic applications.