Remarks on the spectral properties of thermal noise

Some models of thermal noise as generated by electrical resistances are discussed, especially with respect to the corresponding correlation properties. A modified approach for the derivation of the noise power spectrum is proposed. Although, this approach takes into account quantum effects, it leads to a very smooth spectral function. As a consequence, the asymptotic behavior of the corresponding autocorrelation function seems to be closer to reality than those obtained by conventional approaches.