Low-pass distributed RC filter using an MOS transistor with near zero phase shift at high frequencies

The signal transfer properties of an MOS transistor biased with zero drain-to-source voltage, under a four-terminal excitation, are examined. Analytical expressions for the admittance matrix are developed. These results are applied to the study of a distributed RC low-pass filter with phase shift recovery at high frequencies. Calculations for the filter gain and phase characteristics, including the transistor parasitics, are presented. This filter has been used successfully in the design of self-biasing high-gain gigahertz-band amplifiers. The analytical expressions can be easily incorporated in a circuit simulation program to accurately model distributed RC effects