Output Skew Control Option

The HDAWG-SKW Output Skew Control option enhances the skew control resolution of the HDAWG's signal outputs to a value of 10 ps. In comparison, the skew control resolution of the base HDAWG instrument is a single sample clock cycle, i.e., 417 ps at the maximum sampling rate of 2.4 GHz. High-resolution skew control is relevant for some applications that require simultaneous sub-nanosecond signal rise times and inter-channel skew calibration below the nanosecond level.

Note: In many cases, it is possible to achieve sub-sample precision in the timing of the output signals without the hardware change offered by the HDAWG-SKW option. See this blog post to learn how to adjust the timing of an output signal to a resolution much finer than the sampling rate.

HDAWG-SKW upgrade and compatibility

• The upgrade involves a change of the hardware and therefore requires the instrument to be returned and calibrated at Zurich Instruments.
• HDAWG instruments purchased in 2019 or earlier are equivalent in functionality to the HDAWG with the HDAWG-SKW option purchased from 2020 onwards.
• The option is compatible with all other HDAWG options.

On instruments with the HDAWG-SKW option installed, a phase-shift component is placed at the clock input of the digital-to-analog converter (DAC) of each wave output. Without the option, this component is absent and inter-channel skew control is realized exclusively by delaying the digital signal at the input of the DAC in discrete steps of single sampling clock cycles.

The enhanced resolution enabled by the HDAWG-SKW option is counterbalanced by a slight increase of the phase noise and the skew temperature drift. In applications where the highest possible performance relative to the latter specifications is essential, it may thus be advantageous to choose the HDAWG without the HDAWG-SKW option.

For a large class of signals, sub-sample delay control can also be realized without the HDAWG-SKW option. This is achieved by reprogramming the vertical support points of the underlying waveform. With this method, signals with characteristic rise and fall times above 1 ns can typically be shifted on the time axis with a resolution matching or even exceeding the 10 ps resolution offered by the HDAWG-SKW option. However, this approach does not apply to signals with ultra-low rise times generated using waveforms with single-sample steps or single-sample pulses.