| 翻訳と辞書 |
phase noise
In signal processing, phase noise is the frequency domain representation of rapid, short-term, random fluctuations in the phase of a waveform, caused by time domain instabilities ("jitter"). Generally speaking, radio frequency engineers speak of the phase noise of an oscillator, whereas digital system engineers work with the jitter of a clock.
==Definitions==
Historically there have been two conflicting yet widely used definitions for phase noise. Some authors define phase noise to be the spectral density of a signal's phase only, while the other definition refers to the phase spectrum (which pairs up with the amplitude spectrum, see spectral density#Related concepts) resulting from the spectral estimation of the signal itself. Both definitions yield the same result at offset frequencies well removed from the carrier. At close-in offsets however, the two definitions differ.
The IEEE defines phase noise as where the "phase instability" is the one-sided spectral density of a signal's phase deviation.〔, see definition 2.7.〕 Although is a one-sided function, it represents "the double-sideband spectral density of phase fluctuation".〔, stating ℒ(''f'') "is one half the of the double-sideband spectral density of phase fluctuation."〕 The phase noise expression is pronounced "script ell of f".
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「phase noise」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|