Interleaved RF triggering on a test and measurement instrument

摘要

A time-interleaved RF triggering method and system on a test and measurement instrument includes an acquisition component that samples a waveform, which is converted into an amplitude, phase, frequency, in-phase (I), and quadrature (Q) waveform, any of which can be used for triggering an RF digital trigger, including triggering that uses demodulation and/or decoding of the down-converted complex IQ data samples for a given protocol. Aliasing caused by subsampled data in each of the interleaved acquisition components is cancelled out using a fractional time-shift filter.

主权项

1. A test and measurement instrument, comprising:
a sampler component configured to receive a signal under test; a plurality of analog-to-digital converters (ADCs) operationally coupled to the sampler component and configured to produce digitized samples of the signal under test; a time-interleaved acquisition system including a plurality of parallel distributed acquisition components configured in an interleaved chain, each distributed acquisition component being operationally coupled to at least one of the ADCs and configured to receive a time-interleaved portion of the digitized samples, each distributed acquisition component including:
an acquisition digital down-conversion (DDC) section having an interleaved numerically-controlled oscillator (NCO) for decimating the time-interleaved portion of the digitized samples; andan RF trigger finite impulse response (FIR) filter configured to receive and filter the decimated samples from the acquisition DDC section; and a last distributed acquisition component associated with the interleaved chain of distributed acquisition components configured to receive a recombined coherent waveform including the decimated and filtered samples, wherein the last distributed acquisition component includes an RF trigger data convert section that is configured to convert the decimated samples of the recombined waveform into one or more of an amplitude, phase, frequency, in-phase (I), and quadrature (Q) waveforms; wherein each of the distributed acquisition components includes an RF trigger DDC section coupled to the acquisition DDC section, wherein the RF trigger DDC section is configured to shift the center frequency of the digitized samples.