Analysis of the transient dynamics of microwave oscillators

Abstract: A semi-analytical method for the global prediction and understanding of the transient dynamics of oscillator circuits is presented. It covers both the linear and nonlinear transient stages, which are related with the circuit generalized eigenvalues, here introduced for the first time. The transient model relies on the application of the implicit-function theorem to the harmonicbalance system, in order to derive a reduced-order nonlinear differential equation from a given observation node. This requires the extraction of a nonlinear admittance function, depending on the voltage excitation and oscillation frequency, which is done with a forcing auxiliary generator. The linearization of this admittance function for each excitation amplitude provides a sequence of linear ordinary differential equations, describing the system dynamics in the vicinity of each point of the transient trajectory, which can be reconstructed from the expression of the solution increment at each time step. The sequence of differential equations provides a set of generalized eigenvalues, responsible for the acceleration or deceleration of the oscillation growth and capable to detect spurious transient frequencies. The concept of escape time, or time required by the transient trajectory to go through a certain interval of amplitude values, is also introduced, for the first time to our knowledge. The method has been successfully applied to analyze the transient dynamics of several FET oscillators, including dual-frequency oscillators and switched oscillators.

Otras publicaciones de la misma revista o congreso con autores/as de la Universidad de Cantabria

 Fuente: IEEE Transactions on Microwave Theory and Techniques, 2019, 67(9), 3562-3574

Editorial: Institute of Electrical and Electronics Engineers Inc.

 Fecha de publicación: 01/09/2019

Nº de páginas: 14

Tipo de publicación: Artículo de Revista

DOI: 10.1109/TMTT.2019.2931009

ISSN: 0018-9480,1557-9670

Proyecto español: TEC2014-60283-C3- (1/2)-R ; TEC2017-88242-C3-(1/2)-R

Url de la publicación: https://doi.org/10.1109/TMTT.2019.2931009