Noise parameters for metal-oxide-semiconductor transistors

The noise performance of a metal-oxide-semiconductor transistor is represented by a voltage source and a current source at the input to the device. A relationship is established for the noise factor in terms of the magnitudes of these sources, the complex correlation coefficient between them and the input-impedance termination. The conditions for minimum noise factor and the corresponding optimum source impedance are studied. By measuring the variations of noise with source impedance, the noise contributions of the equivalent generators are separated, and results are given for a low-frequency metal-oxide-semiconductor transistor, at frequencies within the band of low noise factor. Measurements are also made showing the variation of the noise factor with source resistance, and with frequency in the range 3¿300kc/s.