Classical active transmission-line analysis of channel thermal noise and induced-gate noise in a MOSFET is extended to include non-quasi-static effects. For long-channel MOSFETs this results in simple analytical expressions exhibiting a frequency-squared correction to channel thermal noise, a fourth power in frequency correction to induced-gate noise and a new real part to the correlation coefficient between the two varying linearly with frequency. Using the channel segmentation approach the results are verified using Spice simulations. The expressions can be extended to include the induced substrate current noise and incorporated in compact models. (c) 2007 Elsevier Ltd. All rights reserved.