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Today, noise measurements have become an essential factor in the
characterization of signals. This is easy to understand when one realizes that
it is phase noise that:
- limits the operating range of radar
- degrades the quality of television pictures
- limits the precision of satellite positioning
- spoils the quality of data transmission
The primary characteristic of noise is its randomness, and this is due to the
physical mechanisms which generate it.
Three leading types of noise are to be found in all electronic systems:
- Thermal Noise: random motion of the carriers in a conductor.
- Shot Noise: random flow of the carriers through a potential barrier.
- Flicker Noise: its origin is not well known. It seems to come from the
macroscopic defects of the materials.
To characterize these noise sources, one must refer to the Theory of Random
Processes. The mathematical tools will be simplified by making three
assumptions according to the statistical process, i.e. on whether it is:
- Stationary (zero mean value)
- Ergodic (its statistical mean values are the same as its time mean values)
- Gaussian (its amplitude has a Gaussian distribution)
【文件名】:06214@52RD_phase_noise_theory.pdf
【格 式】:pdf
【大 小】:519K
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