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Noise experts and some small specialized companies have slowly developed a limited number of calculation tools, which have increased in number and become more user-friendly, covering more application cases, and adding service elements to the noise calculation tools. The noise calculation process is complex in input (gathering data, correctly ...
Friis's formula is used to calculate the total noise factor of a cascade of stages, each with its own noise factor and power gain (assuming that the impedances are matched at each stage). The total noise factor can then be used to calculate the total noise figure. The total noise factor is given as
Leeson's equation is an empirical expression that describes an oscillator's phase noise spectrum. Leeson's expression [1] for single-sideband (SSB) phase noise in dBc/Hz (decibels relative to output level per hertz) and augmented for flicker noise: [2]
Perlin noise is a type of gradient noise developed by Ken Perlin in 1983. It has many uses, including but not limited to: procedurally generating terrain , applying pseudo-random changes to a variable, and assisting in the creation of image textures .
The noise power from a simple load is equal to kTB, where k is the Boltzmann constant, T is the absolute temperature of the load (for example a resistor), and B is the measurement bandwidth. This makes the noise figure a useful figure of merit for terrestrial systems, where the antenna effective temperature is usually near the standard 290 K ...
For thermal noise, its spectral density is given by N 0 = kT, where k is the Boltzmann constant in joules per kelvin, and T is the receiver system noise temperature in kelvins. The noise amplitude spectral density is the square root of the noise power spectral density, and is given in units such as V / H z {\displaystyle \mathrm {V} /{\sqrt ...
The measured dynamic range (DR) of a digital system is the ratio of the full scale signal level to the RMS noise floor. The theoretical minimum noise floor is caused by quantization noise. This is usually modeled as a uniform random fluctuation between − 1 ⁄ 2 LSB and + 1 ⁄ 2 LSB.
If the noise has expected value of zero, as is common, the denominator is its variance, the square of its standard deviation σ N. The signal and the noise must be measured the same way, for example as voltages across the same impedance. Their root mean squares can alternatively be used according to: