Analyzing the dynamic behavior of RF oscillators

Using an asymptotic perturbation method, we perform a full nonlinear analysis of second- and third-order oscillators, widely used in radio frequency (RF) applications. The steady-state oscillation and its orbital stability, as well as the initial transient response are determined through relatively simple and expressive relationships making it possible to establish design criteria. Some practical circuits of RF voltage-controlled oscillators (VCOs), which are representative of wide classes of oscillators, are analyzed. Moreover, a nonlinear perturbation model of differential VCOs is developed to make their nonlinear analysis possible.