M3102A Channel Differencing for Differential I+jQ Measurements

While the Keysight M3102A digitizer does not support analog differential inputs, it is possible with the VSA software to use two of the inputs of the module and difference the data from each to get similar behavior to traditional differential inputs. This can then be used to do differential I+jQ measurements.

To configure this mode, use the custom channel configuration dialog (Input > Channels > Custom...) in the VSA software and select the appropriate inputs. This is an example for differential I+jQ. When using this mode of operation it is important to match the delay between the channels being differenced. Since differences in cable lengths in the system as well as delay differences within the module can affect the delay, it is important to correct for this delay before differencing the data. But the exact delay to correct for is system dependent. Therefore, several input extension delay parameters are provided to allow for adjusting the delay between channels. The delay of each channel is relative to the overall acquisition trigger location.