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Here, k ≈ 1.38 × 10 −23 J/K is the Boltzmann constant and kT 0 is the available noise power density (the noise is thermal noise, Johnson noise). As a numerical example: A receiver has a bandwidth of 100 MHz , a noise figure of 1.5 dB and the physical temperature of the system is 290 K .
In that case, a fixed threshold level can be chosen that provides a specified probability of false alarm, governed by the probability density function of the noise, which is usually assumed to be Gaussian. The probability of detection is then a function of the signal-to-noise ratio of the target return. However, in most fielded systems ...
Specific detectivity is given by =, where is the area of the photosensitive region of the detector, is the bandwidth, and NEP the noise equivalent power in units [W]. It is commonly expressed in Jones units ( c m ⋅ H z / W {\displaystyle cm\cdot {\sqrt {Hz}}/W} ) in honor of Robert Clark Jones who originally defined it.
Noise-equivalent power (NEP) is a measure of the sensitivity of a photodetector or detector system. It is defined as the signal power that gives a signal-to-noise ratio of one in a one hertz output bandwidth. [1] An output bandwidth of one hertz is equivalent to half a second of integration time. [2] The units of NEP are watts per square root ...
A phase frequency detector (PFD) is an asynchronous circuit originally made of four flip-flops (i.e., the phase-frequency detectors found in both the RCA CD4046 and the motorola MC4344 ICs introduced in the 1970s). The logic determines which of the two signals has a zero-crossing earlier or more often.
Flicker noise is a type of electronic noise with a 1/f power spectral density. It is therefore often referred to as 1/ f noise or pink noise , though these terms have wider definitions. It occurs in almost all electronic devices and can show up with a variety of other effects, such as impurities in a conductive channel, generation and ...
Photon noise is the randomness [citation needed] in signal associated with photons arriving at a detector. For a simple black body emitting on an absorber, the noise-equivalent power is given by N E P 2 = 2 h 2 ν 2 Δ ν ( n η + n 2 ) {\displaystyle \mathrm {NEP} ^{2}=2h^{2}\nu ^{2}\Delta \nu \left({\frac {n}{\eta }}+n^{2}\right)}
Johnson–Nyquist noise (thermal noise, Johnson noise, or Nyquist noise) is the electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical conductor at equilibrium, which happens regardless of any applied voltage.