steady state analysis of oscillators
abstract
a common method used for steady-state analysis of oscillators is called harmonic
balance. harmonic balance finds the steady-state solution directly in frequency-domain.
however, harmonic balance is very sensitive to the initial guess and may not converge if the
oscillation frequency is not known a priori. sometimes it may converge to the unstable dc
operating point of the oscillator. moreover, it is usually difficult to have such good initial
guess.
in this thesis, a fast approach is developed to improve the initial guess for harmonic
balance (hb). this approach is derived from minimal polynomial extrapolation (mpe) and
warped multi- time partial differential equation (wampde). the wampde works by
separating the fast and slow variations in the response of oscillators, thus minimizing time
and cpu consumption. the role of mpe is to accelerate the work of wampde. the advantage
of the mpe method is that it saves jacobian matrix decomposition and it is easy to
implement. simulation results of different oscillators (colpitts and lc-tuned bipolar) are
presented to evaluate the performance of the proposed method.