Test and measurement instrument including asynchronous time-interleaved digitizer using harmonic mixing

A harmonic mixer, comprising:

• an input signal splitter configured to split an input signal into a first signal on a first path and a second signal on a second path;
• a mixer configured to mix the first signal and a harmonic signal and to generate a mixed signal on the first path;
• and
• a combiner configured to combine the second signal from the second path and the mixed signal from the first path and to generate an output signal, wherein the first path includes:
• a first attenuator to receive the first signal;
• a highpass filter to receive the first signal from the attenuator;
• a first amplifier to receive the signal from the highpass filter;
• a second attenuator to receive the mixed signal from the mixer;
• and
• a lowpass filter to output the mixed signal to the combiner.

A method, comprising:

• splitting an input signal into a first signal on a first path and a second signal on a second path;
• mixing the first signal and a harmonic signal and generating a mixed signal on the first path;
• and
• combining the second signal from the second path and the mixed signal from the first path and generating an output signal;
• wherein the mixed signal is a first mixed signal and the harmonic signal is a first harmonic signal, the method further including:
• splitting the input signal into the first signal, the second signal, and a third signal on a third path,
• mixing the third signal and a second harmonic signal different from the first harmonic signal and generating a second mixed signal on the third path, and
• combining the second signal, the first mixed signal, and the second mixed signal.