On the intrinsic origin of 1=f noise

The problem of the intrinsic origin of 1=f noise is considered. Currents and signals consisting of a sequence of pulses are analyzed. It is shown that the intrinsic origin of 1=f noise is a random walk of the average time between subsequent pulses of the pulse sequence, or the interevent time. This results in the long-memory process for the pulse occurrence time and in 1=f type power spectrum of the signal. Ó 2000 Elsevier Science Ltd. All rights reserved.