The analysis and demonstration of a method of generating v.l.f. noise

The paper describes the analysis of a method of generating v.l.f. white noise based on the sampling principle. A wide-band source of noise is used and a narrow band at fairly high frequency over which the power spectrum is flat is extracted using a band-pass filter. The power spectral densities that result from sampling this band for different sampling frequencies are derived. The case of practical importance resulting in a flat spectral density around zero frequency is demonstrated experimentally for different sampling rates and the resultant maximum r.m.s. noise voltage compared with the theoretical values.