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Receiver noise power
NPOWER = noisepow(NBW,NF,REFTEMP)
NPOWER = noisepow(NBW,NF,REFTEMP) returns the noise power, NPOWER, in watts for a receiver. This receiver has a noise bandwidth NBW in hertz, noise figure NF in decibels, and reference temperature REFTEMP in degrees kelvin.
NBW |
The noise bandwidth of the receiver in hertz. For a superheterodyne receiver, the noise bandwidth is approximately equal to the bandwidth of the intermediate frequency stages [1]. |
NF |
Noise figure. The noise figure is a dimensionless quantity that indicates how much a receiver deviates from an ideal receiver in terms of internal noise. An ideal receiver only produces the expected thermal noise power for a given noise bandwidth and temperature. A noise figure of 1 indicates that the noise power of a receiver equals the noise power of an ideal receiver. Because an actual receiver cannot exhibit a noise power value less than an ideal receiver, the noise figure is always greater than or equal to one. |
REFTEMP |
Reference temperature in degrees kelvin. The temperature of the receiver. Typical values range from 290–300 degrees kelvin. |
NPOWER |
Noise power in watts. The internal noise power contribution of the receiver to the signal-to-noise ratio. |
Calculate the noise power of a receiver whose noise bandwidth is 10 kHz, noise figure is 1 dB, and reference temperature is 300 K.
npower = noisepow(10e3,1,300);