Calibration for test and measurement instrument including asynchronous time-interleaved digitizer using harmonic mixing

A test and measurement instrument, comprising:

• an input port for receiving an input signal from a device under test (DUT);
• a compensation signal generator for generating a compensation signal;
• a switch coupled to the input port and to the compensation signal generator;
• an asynchronous time-interleaved (ATI) digitizer coupled to the output of the switch, the ATI digitizer including
• a splitter,
• an analog mixing portion coupled to the splitter,
• a digitizing portion coupled to the analog mixing portion,
• a digital filtering portion coupled to the digitizing portion,
• a digital mixing portion coupled to the filtering portion, and
• a combiner coupled to the digital mixing portion;
• and
• a processor configured to perform a compensation procedure, by
• causing the switch to couple the compensation signal to the ATI digitizer,
• determining a signal reconstruction error of the ATI digitizer by measuring the output of the ATI digitizer in response to the compensation signal, and
• altering operation of the ATI digitizer to remove the signal reconstruction error.

A test and measurement instrument, comprising:

• an asynchronous time-interleaved (ATI) digitizer including an input and producing an output signal;
• means for providing a known compensation signal to the input of the ATI digitizer;
• means for measuring the output signal of the ATI digitizer in response to the known compensation signal;
• means for adjusting a parameter of the ATI digitizer to minimize magnitude and phase differences between the output signal of the ATI digitizer and the known compensation signal.