Abstract: A test and measurement instrument including an oscillator configured to generate a periodic signal; a mixer configured to mix an input signal with the periodic signal to generate a frequency-shifted signal; a trigger system configured to generate a trigger signal; a phase detector configured to sense a phase between the trigger signal and the periodic signal; and a controller configured to adjust processing of the frequency-shifted signal in response to the phase.

Abstract: A signal generator produces a victim signal having crosstalk emulation by filtering and combining a victim signal waveform record file and an aggressor signal waveform record file generated using parameters selected by a user. A signal channel or a cascaded signal channel is characterized using one or more S-parameter arrays. The S-parameter array or arrays represent a mixed-mode multiple-port device under test. Coefficients of a NEXT filter, a FEXT filter and a forward transmission filter are derived from selected S-parameters of the S-parameter array. The aggressor signal is filtered individually by the NEXT and FEXT filters. The victim signal is summed with the filtered aggressor signal from the NEXT filter with the resulting summed signal being filtered by the forward transmission filter. The filtered signal from the forward transmission filter is summed with the filtered aggressor signal from the FEXT filter to generate a victim signal having crosstalk emulation.

Abstract: In a multi-channel oscilloscope a method of calibrating interleaved digitizer channels initially calibrates each digitizer channel to produce a bandwidth enhanced filter for each digitizer channel to match the respective channel frequency and phase characteristics. The oscilloscope is then configured for interleaved operation whereby an input signal is applied to at least two digitizers via a switch through a common preamplifier to produce a reference digitizer channel and an interleaved digitizer channel where the bandwidth enhanced filter for the interleaved digitizer channel is now not correct. Fast Fourier transforms are performed on the data from the reference digitizer channel and the interleaved digitizer channel, from which are derived a match filter for the interleaved digitizer channel so the interleaved digitizer channel and reference digitizer channel are matched in phase and magnitude at all frequencies.

Abstract: A signal acquisition probe stores compressed or compressed and filtered time domain data samples representing at least one of an impulse response or step response characterizing the signal acquisition probe. The compressed or compressed and filtered time domain data samples of the impulse response or the step response are provided to a signal measurement instrument for compensating the signal measurement instrument for the impulse or step response of the signal measurement instrument.

Abstract: A system and method of making frequency domain measurements on a waveform acquired by a time domain instrument, such as an oscilloscope, uses built-in FFT spectral analysis in the time domain instrument so that a user can perform the compliance measurements using the oscilloscope alone. The results of the measurement made by the oscilloscope are made comparable to those made by a spectral analyzer by improving dynamic range, noise floor, and measurement accuracy, by averaging on the time domain oscilloscope.

Abstract: A system and method for performing power spectral density (PSD) and power level measurements for measuring PSD required by 10GBaseT applications, using a single test and measurement instrument, such as a real time oscilloscope is described. That is, an oscilloscope includes processing circuitry which receives an input signal and converts it to raw data, it then transforms the raw data into specific analyzed displayable data by algorithmically deriving PSD from spectral data and plotting the PSD data along with limit values on a display screen of the oscilloscope.

Abstract: An acquisition apparatus for a test and measurement instrument including a splitter configured to split an input signal into a plurality of split signals, a plurality of oscillators, each oscillator configured to generate a periodic signal, a plurality of combiners, each combiner configured to combine an associated plurality of the periodic signals into an associated signal combination where at least one of the signal combinations is substantially non-periodic. The apparatus also includes a plurality of mixers, each mixer configured to mix an associated split signal and an associated signal combination into an associated mixed signal, a first digitizer configured to digitize an associated split signal, and a plurality of second digitizers, each second digitizer configured to digitize an associated mixed signal.

Abstract: A method and apparatus adapted to calibrate a signal path of a signal analysis system such that loading effects of the system are substantially removed from measurements of a device under test. A signal under test from the device under test is coupled to a test probe in the signal path and used with selectable impedance loads in the test probe to characterize transfer parameters of the device under test. An equalization filter in either the frequency or time domain is computed from the device under test transfer parameters for reducing in signal error attributable to the measurement loading of the device under test.

Abstract: An acquisition apparatus for a test and measurement instrument including a splitter configured to split an input signal into a plurality of split signals, a plurality of oscillators, each oscillator configured to generate a periodic signal, a plurality of combiners, each combiner configured to combine an associated plurality of the periodic signals into an associated signal combination where at least one of the signal combinations is substantially non-periodic. The apparatus also includes a plurality of mixers, each mixer configured to mix an associated split signal and an associated signal combination into an associated mixed signal, a first digitizer configured to digitize an associated split signal, and a plurality of second digitizers, each second digitizer configured to digitize an associated mixed signal.

Abstract: A method and apparatus adapted to calibrate signal path of a signal analysis system such that loading effects of additional probes are substantially removed from the measurement. A signal under test from a device under test is coupled to a test probe and used with selectable impedance loads in the test probe to acquires sets of samples for characterizing transfer parameters of the device under test and compute open circuit voltages at the test probe. Other probes are coupled to the device under test and a set of measurement samples are acquired via the test probe. An equalization filter in either the frequency or time domain is computed from the open circuit voltage and measurement samples for reducing signal errors attributable to the measurement loading of the device under test by the test probe and other probes.

Abstract: A method and apparatus adapted to calibrate a signal path of a signal analysis system such that digital samples acquired by the system are processed for representing an arbitrary impedance loading of the device under test. The method and apparatus calibrates the signal path to characterize transfer parameters of the device under test within a spectral domain. A reflection coefficient (?L) is defined representative of an arbitrary impedance load coupled to the device under test and an equalization filter is computed to represent the loading of the device under test by the arbitrary impedance. Additional digital samples are acquired using the equalization filter to effect thereby a representation of the arbitrary impedance loading of the device under test.

Abstract: A method and apparatus adapted to calibrate a signal path of a signal analysis system such that digital samples of a signal under test acquired by the system are processed for representing the impedance of a device under test. The method and apparatus calibrates the signal path to characterize transfer parameters of the device under test within a spectral domain. A reference impedance (Zref) is retrieved that is associated with the signal analysis system. The transfer parameters of the device under test and the reference impedance (Zref) are processed to effect thereby a representation of the device under test impedance (Zeq) as a function of frequency.

Abstract: A realtime spectrum trigger system on a realtime oscilloscope considers both the magnitude and phase of an input signal having a periodic component so that successive acquisitions of the input signal are time aligned. A user inputs a frequency, threshold and phase for triggering on the periodic component. Input signal samples are filtered by quadrature filters according to the frequency input to produce quadrature signal components. The square of the magnitude of the input signal is computed from the quadrature signal components, as well as the phase ratio and sign, for comparison with calculated values. When enabled by the magnitude of the input signal, a phase crossing determinator compares the phase ratio and sign with calculated values to determine the phase crossing to generate a trigger, resulting in successive acquisitions of the input signal being in time alignment.

Abstract: A method and apparatus adapted to calibrate a signal path of a signal analysis system such that digital samples acquired by the system are processed for representing an arbitrary impedance loading of the device under test. The method and apparatus calibrates the signal path to characterize transfer parameters of the device under test within a spectral domain. A reflection coefficient (FL) is defined representative of an arbitrary impedance load coupled to the device under test and an equalization filter is computed to represent the loading of the device under test by the arbitrary impedance. Additional digital samples are acquired using the equalization filter to effect thereby a representation of the arbitrary impedance loading of the device under test.

Abstract: A method and apparatus adapted to calibrate a signal path of a signal analysis system such that loading effects of the system are substantially removed from measurements of a device under test. A signal under test from the device under test is coupled to a test probe in the signal path and used with selectable impedance loads in the test probe to characterize transfer parameters of the device under test. An equalization filter in either the frequency or time domain is computed from the device under test transfer parameters for reducing in signal error attributable to the measurement loading of the device under test.

Abstract: A method and apparatus adapted to calibrate signal path of a signal analysis system such that loading effects of additional probes are substantially removed from the measurement. A signal under test from a device under test is coupled to a test probe and used with selectable impedance loads in the test probe to acquires sets of samples for characterizing transfer parameters of the device under test and compute open circuit voltages at the test probe. Other probes are coupled to the device under test and a set of measurement samples are acquired via the test probe. An equalization filter in either the frequency or time domain is computed from the open circuit voltage and measurement samples for reducing signal errors attributable to the measurement loading of the device under test by the test probe and other probes.

Abstract: A method and apparatus adapted to calibrate a signal path of a signal analysis system such that digital samples of a signal under test acquired by the system are processed for representing the impedance of a device under test. The method and apparatus calibrates the signal path to characterize transfer parameters of the device under test within a spectral domain. A reference impedance (Zref) is retrieved that is associated with the signal analysis system. The transfer parameters of the device under test and the reference impedance (Zref) are processed to effect thereby a representation of the device under test impedance (Zeq) as a function of frequency.

Abstract: A method of de-embedding test probes coupled to an oscilloscope system to compensate for the loading of the test probes on a device under test. The method includes connecting each test probe individually to the device under test and calibrating each test probes to characterize transfer parameters of the device under test within a spectral domain. The open voltage of the device under test is calculated for each test probe. The test probes are connected to the device under test ans measurement samples are acquired by each of the test probes in the time domain and converted to the spectral domain. An equalization filter is computed for each of the test probes to compensate for loading of the device under test caused by the test probes using the spectral domain open voltage and measurement samples for each of the test probes.

Abstract: A method and apparatus adapted to calibrate a test probe and oscilloscope system such that digital samples acquired by the system are processed for representing an arbitrary impedance loading of the device under test. The method and apparatus calibrates the test probe to characterize transfer parameters of the device under test within a spectral domain. A reflection coefficient (L) is defined representative of an arbitrary impedance load coupled to the device under test and an equalization filter is computed to represent the loading of the device under test by the arbitrary impedance. Additional acquired samples are acquired using the equalization filter to effect thereby a representation of the arbitrary impedance loading of the device under test.

Abstract: A multiband amplifier for a test and measurement instrument includes a splitter to split an input signal into split signals, amplifiers, and means for combining and digitizing the amplified signals into a digitized signal. Each amplifier is configured to amplify an associated split signal over an amplifier passband. The amplifier passband of at least one amplifier is different from the amplifier passband of another amplifier.