THERMAL NOISE

The noise generated by thermal agitation of electrons in a conductor. The noise power , P , in watts, is given by P = k T f , where k is Boltzmann's constant in joules per kelvin , T is the conductor temperature in kelvins, and f is the bandwidth in hertz . ( 188 ) Note 1: Thermal noise power, per hertz, is equal throughout the frequency spectrum, depending only on k and T . Note 2: For the general case, the above definition may be held to apply to charge carriers in any type of conducting medium . Synonym Johnson noise.