Equivalent time network analyzer

An equivalent time network analyzer, comprising:

• a timing system configured to produce a first time basis and a second time basis that differ in period by less than one part per million, resulting in a linearly varying phase difference between the first time basis and the second time basis;
• at least one high frequency stimulus generator configured to receive timing input according the first time basis and create a periodic waveform that is synchronized to the first time basis and that contains energy at the harmonics of the first time basis that are of interest for measurement, the stimulus generator being connected to an input of a device-under-test so as to be able to stimulate the device-under-test;
• and
• at least one output capture cell connected to an output of the device-under-test so as to be able to capture an electrical response of the device-under-test to a stimulus from the stimulus generator, each capture cell comprising:
• a high bandwidth input comparator configured to process the electrical response and produce a result;
• a clocked memory element configured to hold the result received from the high bandwidth input comparator according to the second time basis;
• and
• a low bandwidth feedback filter configured to convert the result from the high bandwidth comparator to a lower frequency analog signal and provide a low frequency analog estimate of a time domain response of the device-under-test as feedback to the input comparator and as an output from the output capture cell.