Mathematical basis of the expressions used by the integral function method for the determination of nonlinear harmonic distortion in devices and circuits

In this paper we demonstrate the relation of the integral functions D and Dr used in the integral function method for the determination of the nonlinear harmonic distortion in devices and circuits, with the total harmonic distortion, TDH, second order harmonic distortion HD2 and third order harmonic distortion, HD3. A review of the basic aspects of the IFM is presented, as well as an example of its application.