# Frequency in hz in view of the above we can write dp

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frequency in Hz. In view of the above we can write dP n = hf e hf/KT - 1 df hf KT -→ KTdf for power available over an infinitesimal bandwidth df . Hence, over a finite bandwidth B in the frequency range f KT/h , where dP n is independent of f , the available noise power of a resistor is P n = KTB. It is convenient to define a noise phasor V n , with a mean-square denoted as | V n | 2 , such that P n = KTB | V n | 2 8 R B. The noise phasor V n represents a co-sinusoid that carries the same average power as noise voltage v ( t ) over a unit bandwidth 8 , and can be treated as a regular voltage phasor 8 Any bandwidth unit can be employed here, e.g., Hz, kHz, or even μ Hz, as long as the same unit is used to express B in the formula for P n . 120