Some practical applications of a nonlinear block structure identification procedure

In this paper, a structure identification method based upon the best linear approximation which was presented in earlier work is applied to three different physical systems: the silverbox, a crystal detector, and an RF amplifier. The approach of this method consists in applying a Gaussian-like input signal, and to vary in a first experiment the root mean square (rms) value of this signal while maintaining the colouring of the power spectrum. Next, in a second experiment the colouring of the power spectrum is varied while keeping the rms value constant. Based on the resulting behaviour of the best linear approximation, a distinction can be made between candidate nonlinear block structures for approximating the real system.