Low-distortion signal generation for ADC testing

This paper describes a method of generating low-distortion sinusoidal waves using an arbitrary waveform generator (AWG), and experimental results of using such a generator for ADC dynamic performance testing. With this proposed method, 3^rd order harmonics of the generated signal are suppressed simply by changing the AWG program (or waveform memory contents)-AWG nonlinearity identification is not required-and spurious components, generated far from the signal band, are relatively easy to remove using an analog filter; our theoretical analyses, simulations, and experiments showed that a simple passive LC analog filter (with relaxed requirements compared to the one for direct HD3 removal) is sufficient. Our ADC testing results-using signals generated by an AWG with the proposed algorithm, and a simple passive LC LPF-show measurement errors (caused by 3^rd order harmonics generated by AWG DAC nonlinearity) half that of previous algorithms.