High accuracy Fourier analysis based on synchronous sampling techniques

The lack of synchronization between the sampling rate and the signal frequency represents the main source of errors in the frequency analysis of periodic signals performed by means of digital techniques. Several algorithms have been proposed in the literature to reduce these errors, at the cost of an increment in the computational burden imposed by the instrument. The complete elimination of these errors can be achieved only when the sampling rate is synchronized to the fundamental frequency of the signal to be analyzed. It is shown how this can be attained, and the results of fast Fourier transforms (FFTs) performed on multifrequency signals under synchronous sampling conditions are indicated. The accuracy of these measurements is discussed