An Algorithm for Selecting Sampling Rate in Arbitrary Waveform Generator

Abstract

To solve the problem that auto test equipment (ATE) user cannot set an appropriate output sampling rate due to the missing of arbitrary waveform generator's internal parameters, this paper proposes a sampling rate selecting algorithm based on rational sampling rate conversion (RSRC) theory. Under anti-aliasing conditions, the algorithm selects an output sampling rate, as fractional-times (L/M) as original one, in acceptable range and converts waveform to the output sampling rate by RSRC. In this algorithm, the acceptable sampling rate range can be calculated and be used to get the upper limit of L. Since the value of output waveform length must be less than the memory depth, lower limit of the required memory depth is obtained when a complete waveform can be generated. The experiment result shows that the computational complexity of sampling rate conversion and required memory depth of AWG are both reduced with proposed algorithm comparing with fixed RSRC; the harmonic of output signal is decreased with proposed algorithm comparing with arbitrary sampling rate conversion (ASRC).