Polynomial approximation of the transfer function of an analog-to-digital converter

Abstract

In this paper the polynomial approximation of the transfer function of an analog-to-digital converter (ADC) affected by harmonic distortions is investigated. The theoretical expression of the polynomial approximation of the transfer function of an ADC with harmonic components up to 5th order in the case of a sinewave test signal is derived. Also, a practical method to determine the polynomial approximation of an ADC is proposed. The simulation effected confirmed that the results obtained by this method are very accurate. Moreover, an ADC test system, developed to determine the polynomial approximation of the transfer function of an ADC by the proposed method is presented. Some experimental results obtained with this test system are given. Keywords: Analog-to-digital converter (ADC), polynomial approximation of the transfer function of an ADC, interpolated fast Fourier transform (IFFT).