The paper by Peled et al. (2000, International Journal of Electronics, 87, 1-9) reports a quantitative comparison between the low frequency excess 1/fnoise obtained on trimmed and untrimmed bismuth ruthenate thickfilm resistors (TFRs). The empirical relation of Hooge was used to quantify and compare the 1/fnoise level. Peled et al. concluded that the Hooge parameter aH increases for trimmed TFRs. In this comment it will be shown that misusing the Hooge relation for nonhomogeneous materials can lead to misleading high apparent a values describing not the 1/fproperties of the material but the current crowding in the material.
Mercha, A., Feyaerts, R., & Vandamme, L. K. J. (2001). Comment on comparison of excess 1/f noise spectra in trimmed and untrimmed thick film resistors. International Journal of Electronics, 88(3), 315-319. https://doi.org/10.1080/00207210010013193