Analytical model of noise in an analog frequency divider

The noise properties of a microwave analog frequency divider are investigated. The division is realized with a field effect transistor (FET) in a forced oscillation mode. An appropriate model is proposed for the calculation of the output signal phase and amplitude noise from the input signal phase noise and from the transistor low-frequency noise data. Specifically, an analog X-band FET frequency divider has been modeled using two nonlinearities and the conversion matrix method. Good agreement has been found between measured and simulated data. The model has been used to explain the phase noise division through the divider and to make clearer the working limits of such a circuit.<>