The electrical characteristics of random RC networks and the physical origin of 1/f noise

Simulations of the electrical noise in large networks of randomly positioned resistors and capacitors show a network noise power spectral density that varies as 1/f(alpha)(0 < alpha < 1). This is found to occur across the frequency range over which the effective network dielectric loss, tan delta, is almost constant. It is suggested that the origin of 1/f noise, for some materials, is an inhomogenous microstructure that acts as an effectively random network of conductive and capacitive regions.