Chaos in Si MMIC Oscillators

This paper analyzes the dynamics of two Si circuits in millimetric band for which chaotic responses had been experimentally observed. The aim has been to deternmine, in each case, the particular phenomena leading to the chaotic response, in order to avoid this behavior in future realizations of these circuits. The most influential parameters have been determined, analyzing the routes to chaos under variations of these parameters. Then some frequency-domain techniques have been developed for the detection of the initial bifurcations taking place in these routes from standard harmonic-balance simulators. This should be more efficient in terms of design time and enable the chaos prediction when time domain simulations are not well suited. Two circuits based on an IMPATT diode have been analyzed, one of them being a self-oscillating mixer, obtaining very good agreement with former experimental observations.