With the widespread demand for high-precision controllable pulse signals in electronic systems such as communications, radar, and quantum computing, the timing resolution and waveform flexibility adjustment capability of excitation signal sources are more demanding. However, direct digital synthesis (DDS) techniques are limited by timing resolution, while computational synthesis methods are computationally complex and resource-consuming despite higher accuracy. In this paper, an improved DDS pulse waveform synthesis method is proposed, which effectively reduces the storage requirement by storing only the pulse waveform edge samples as feature samples instead of all the samples in the complete waveform period. Meanwhile, combining with the adaptive phase adjustment algorithm, the phase offset value is calculated based on the overflow result of the phase accumulator, and the edge position is adjusted to realize the waveform fitting with higher timing resolution. The feature-fitting scheme streamlines the data storage content while avoiding the complexity of real-time computation, achieving a balance between computational resources and memory usage. The method uses 1 GSPS sampling rate and 1 BRAM to successfully synthesize pulse waveforms with timing resolutions of 100 ps and 10 ps, realizes edge time and amplitude adjustments, and achieves an rms jitter of 10.04 ps. The method provides a feasible solution for high-precision pulse signal synthesis with low storage occupation and provides theoretical and practical support for the realization of high-performance electronic test equipment.
Deng et al. (Mon,) studied this question.