noise power density

The noise power in a bandwidth of 1 Hz, i.e., the noise power per hertz at a point in a noise spectrum. Note: The noise-power density of the internal noise that is contributed by a receiving system to an incoming signal is expressed as the product of Boltzmann's constant, k, and the equivalent noise temperature, T_n. Thus, the noise-power density is often expressed simply as kT. Synonym kT. [From Weik '89]