The present disclosure provides a measurement application device comprising at least one signal acquisition interface configured to acquire an analog input signal and output a digital input signal, a first decimator for each signal acquisition interface, each one of the first decimators being configured to reduce the number of samples of the respective digital input signal and output a first decimated digital input signal, at least one second decimator for each signal acquisition interface, each one of the second decimators being configured to reduce the number of samples of the respective digital input signal and output a second decimated digital input signal, and at least one decoder for each one of the second decimators, each one of the decoders being configured to decode the respective second decimated digital input signal according to a respective protocol and provide a respective decoded input signal.

A composite analog-to-digital converter (ADC) has a low resolution ADC configured to receive and digitize analog data, the low resolution ADC having a low resolution and a high operating speed, one or more high resolution ADCs configured to receive and digitize the analog data, the one or more high resolution ADCs having a resolution higher than the low resolution ADC, and an operating speed lower than the high operating speed of the low resolution ADC, a sample clock generator to provide a sample clock signal to the low resolution ADC and to a clock divider, a mixer to receive the analog data and connected to the one or more high resolution ADCs, a local oscillator connected to the mixer to allow the one or more high resolution ADCs to be tuned to sample a portion of a spectrum of the first ADC. A test and measurement instrument contains a composite ADC. A method of operating a composite analog-to-digital converter (ADC), includes receiving an analog signal at a low resolution ADC that operates at a high speed, receiving the analog signal at one or more high resolution ADCs that operate at a resolution higher than the low resolution ADC and at a lower speed than the operating speed of the low resolution ADC, tuning the high resolution ADC to phase align and time align a signal path for the one or more high resolution ADCs to the signal path for the low resolution ADC, producing a spectrum from the low resolution ADC, and producing a portion of the spectrum from the one or more high resolution ADCs.

A dynamic test method includes configuring a dynamic test set-up for a device under test (DUT), the dynamic test set-up including at least one de-skewed voltage probe and at least one de-skewed current measurement cable connected to respective channels of an oscilloscope, and a current sensor connected to the de-skewed current measurement cable and configured to measure a current of the DUT. The method further includes conducting a dynamic test set-up for the DUT using the dynamic test set-up to obtain a current waveform for display on the oscilloscope, and applying a transfer function of the current sensor to the current waveform to display a corresponding de-embedded current waveform on the oscilloscope.

A test and measurement device includes one or more ports configured to connect to a device under test (DUT), a time domain reflectometry (TDR) source configured receive a source control signal and to produce an incident signal to be applied to the DUT, one or more analog-to-digital converters (ADC) configured to receive a sample clock and sample the incident signal from the TDR source and a time domain reflection (TDR) signal or a time domain transmission (TDT) signal from the DUT to produce an incident waveform and a TDR/TDT waveform, one or more processors configured to execute code to cause the one or more processors to: control a clock synthesizer to produce the sample clock and the source control signal, and use a period of the TDR source, a period of the sample clock, and the number of samples to determine time locations for samples in the incident waveform and the TDR/TDT waveform, and a display configured to display the incident waveform and the TDR/TDT waveform. A method of sampling a waveform using a real-equivalent-time oscilloscope having a time domain reflectometry source, comprising: controlling a clock synthesizer to produce a sample clock and a source control signal; using a time domain reflectometry (TDR) source to receive the source control signal and to produce an incident signal to be applied to a device under test (DUT); receiving the sample clock at one or more analog-to-digital converters (ADC) and sampling the incident signal from the TDR source and a TDR/TDT signal from the DUT to produce an incident waveform and a TDR/TDT waveform; determining time locations for samples in the incident waveform and the TDR/TDT waveform, using a period of the TDR source, a period of the sample clock, and a number of samples; and displaying the incident waveform and the TDR/TDT waveform.

Disclosed are systems and methods related to a noise reduction device employing an analog filter and a corresponding inverse digital filter. The combination and placement of the filters within the systems aids in reducing noise introduced by processing the signal. In some embodiments, the combination of filters may also provide for increased flexibility when de-embedding device under test (DUT) link attenuation at higher frequencies. Further, the filters are adjustable, via a controller, to obtain an increased signal to noise ratio (SNR) relative to a signal channel lacking the combination of filters. Additional embodiments may be disclosed and/or claimed herein.

Methods and apparatus are described for detecting anomalies in a clock signal. Example methods include sensing a clock signal that exhibits alternating phases during normal operation; responsive to sensing the start of a first phase, generating a pulse; and if the pulse terminates before sensing the end of the first phase, asserting a clock stopped detection signal. Example clock anomaly detection apparatus includes a clock signal input for coupling to a clock signal that, during normal operation, oscillates between first and second clock states. An anomaly detection output is asserted if the clock signal remains in the first clock state longer than a first phase expected duration or remains in the second clock state longer than a second phase expected duration.

A measurement device for measuring the impedance of a device under test is described. Said measurement device comprises at least one signal generator for generating a signal with a certain frequency wherein said signal is used for testing said device under test. Said measurement device further has at least one shunt resistor that is used for determining the electric current of said signal. Said device also comprise at least two voltage channels for measuring the voltage across said device under test. Said measurement device is an oscilloscope having at least four voltage inputs and wherein said measurement device is configured to derive the impedance of said device from said electric current and said voltage. Further, a method for measuring the impedance of a device under test is described.

Systems and methods directed towards reducing noise introduced into a signal when processing the signal are discussed herein. In embodiments a signal may initially be split by a multiplexer into two or more frequency bands. Each of the frequency bands can then be forwarded through an assigned channel. One or more channels may include an amplifier to independently boost the signal band assigned to that channel prior to a noise source within the assigned channel. This results in boosting the signal band relative to noise introduced by the noise source. In some embodiments, a filter may also be implemented in one or more of the channels to remove noise from the channel that is outside the bandwidth of the signal band assigned to that channel. Additional embodiments may be described and/or claimed herein.

A test and measurement instrument, such as an oscilloscope, having a Nyquist frequency lower than an analog bandwidth, the test and measurement instrument having an input configured to receive a signal under test having a repeating pattern, a single analog-to-digital converter configured to receive the signal under test and sample the signal under test over a plurality of repeating patterns at a sample rate, and one or more processors configured to determine a frequency of the signal under test and reconstruct the signal under test based on the determined frequency of the signal, the pattern length of the signal under test, and/or the sample rate without a trigger.

Embodiments of the present invention provide techniques and methods for improving signal-to-noise ratio (SNR) when averaging two or more data signals by finding a group delay between the signals and using it to calculate an averaged result. In one embodiment, a direct average of the signals is computed and phases are found for the direct average and each of the data signals. Phase differences are found between each signal and the direct average. The phase differences are then used to compensate the signals. Averaging the compensated signals provides a more accurate result than conventional averaging techniques. The disclosed techniques can be used for improving instrument accuracy while minimizing effects such as higher-frequency attenuation. For example, in one embodiment, the disclosed techniques may enable a real-time oscilloscope to take more accurate S parameter measurements.