Abstract: Automatic test equipment (ATE) includes: a circuit to split a stimulus signal, which contains both deterministic and random (noise floor) spectra contents, from a device under test (DUT) into a first signal and a second signal; a first channel to receive the first signal, where the first channel adds a first noise floor to the first signal to produce a first channel signal; a second channel to receive the second signal, where the second channel adds a second noise floor to the second signal to produce a second channel signal, the first noise floor, the second noise floor and the DUT noise floor all being mutually uncorrelated; and processing logic to: estimate a first power of the deterministic stimulus signal, and estimate a second total power based on the first channel signal and the second channel signal.

Abstract: Automatic test equipment (ATE) includes: a circuit to split a stimulus signal, which contains both deterministic and random (noise floor) spectra contents, from a device under test (DUT) into a first signal and a second signal; a first channel to receive the first signal, where the first channel adds a first noise floor to the first signal to produce a first channel signal; a second channel to receive the second signal, where the second channel adds a second noise floor to the second signal to produce a second channel signal, the first noise floor, the second noise floor and the DUT noise floor all being mutually uncorrelated; and processing logic to: estimate a first power of the deterministic stimulus signal, and estimate a second total power based on the first channel signal and the second channel signal.

Abstract: A technique for deskewing digitizer channels in an automatic test system includes applying a waveform of known frequency to the input of each digitizer channel. Each digitizer channel samples the waveform to produce a respective data record. A Discrete Fourier Transform (DFT), or a portion thereof, is then taken for each data record to determine, at minimum, the phase of the waveform. Phase differences across different digitizer channels are converted to time differences, which values are applied to subsequent digitizer measurements to correct for timing skew. Because a large number of samples in a digitizer's data record contribute to the computed phase of the waveform, the effects of timing jitter are substantially eliminated from skew measurements, without the need for repeating measurements and explicitly averaging results.

Abstract: A technique for deskewing digitizer channels in an automatic test system includes applying a waveform of known frequency to the input of each digitizer channel. Each digitizer channel samples the waveform to produce a respective data record. A Discrete Fourier Transform (DFT), or a portion thereof, is then taken for each data record to determine, at minimum, the phase of the waveform. Phase differences across different digitizer channels are converted to time differences, which values are applied to subsequent digitizer measurements to correct for timing skew. Because a large number of samples in a digitizer's data record contribute to the computed phase of the waveform, the effects of timing jitter are substantially eliminated from skew measurements, without the need for repeating measurements and explicitly averaging results.