Keysight 3458A Digitiser Complex Frequency Response Identification using a Band Limited Square Wave

This paper describes an evaluation of the Keysight 3458A digital multimeter (DMM) amplitude and phase response. A band limited square wave signal is proposed as a high accuracy test signal to obtain both responses in a single measurement. Results confirm previous amplitude response measurements and provide insight into the phase response of DMM. A manufacturer's specifications for trigger delay are not confirmed.