A Nonlinear Order-Reducing Behavioral Modeling Approach for Microwave Oscillators

Michael Kraemer (1) , Daniela Dragomirescu (1) , Robert Plana (1)

1 LAAS-MINC - Équipe MIcro et Nanosystèmes pour les Communications sans fil

This paper describes a novel technique to model the transient, steady state, and phase-noise behavior of microwave oscillators in the hardware description language VHDL-AMS. It can be applied to a large variety of both single-ended and differential voltage-controlled oscillators independently of their architecture. The model is derived from data obtained by a more complex circuit-level model. As opposed to input-output models of a microwave two-port, where the output follows more or less the applied input signal, the output of an oscillator depends mainly on its former state. Thus, approaches developed for input-output modeling cannot be applied. The technique proposed in this paper approximates the dynamics of the oscillator by a system of two first-order ordinary differential equations. The oscillator's nonlinear characteristics are reproduced by a multilayer perceptron neural network. In addition to reproducing the oscillator's large-signal waveform, its phase- noise characteristic in the l/f2 and flat region is emulated. Finally, a VHDL-AMS implementation of the model is proposed and associated issues are addressed. The suitability of the model for oscillators at millimeter waves is demonstrated by examples working at 60 GHz.

Mots clés: nonlinear; behavorial modeling; VHDL-AMS; VCO; multilayer perceptron

Domaines: Réseaux et télécommunications [cs.NI]; Electromagnétisme; Electronique; Micro et nanotechnologies/Microélectronique

Michael Kraemer, Daniela Dragomirescu, Robert Plana. A Nonlinear Order-Reducing Behavioral Modeling Approach for Microwave Oscillators. IEEE Transactions on Microwave Theory and Techniques, 2009, 57 (4), pp. 991 - 1006. ⟨hal-00420342⟩