Nonlinear Analysis of a High-Power Oscillator Inductively Coupled to an External Resonator

This contribution presents a detailed nonlinear analysis of a high-power oscillator that is inductively coupled to an external resonator for power transfer applications. The analytical formulation of a cubic nonlinearity oscillator enables the derivation of the maximum transferred power and the value of the coupling factor at which the oscillation is extinguished. Then, a simple procedure to obtain a Class E oscillator from an initial high efficiency oscillator is presented. The solution curves versus the coupling factor and the elements of the external resonator are easily obtained from the extraction of a bi-variate nonlinear admittance function accounting for the oscillator circuit, which is combined with the passive admittance of the coupled resonator. Very good correspondence has been obtained between simulation and measured results.