Abstract: A method of equalizing a communication link includes setting a number of coefficients equal to a required number of coefficients, determining a number of pulse responses for a waveform, the number of pulse responses being greater than the number of coefficients, setting all values in a set of values to zero, the set of values having a number of values equal to the number of coefficients, repeating, until all values in the set of values have been assigned, determining a current lowest parameter in a set of given parameters, using a position of the current lowest parameter in the set of given parameters as an index, determining a minimum value between a first term in the set of given parameters multiplied by a main pulse response minus a summation of each parameter in the set of parameters multiplied by each value in the set of values, divided by the current lowest parameter, and a corresponding pulse response, and assigning the minimum value to the value in the set of values having a position equal to position

Abstract: A test and measurement system includes a test and measurement device configured to receive a signal from a device under test, and one or more processors configured to execute code that causes the one or more processors to generate a waveform from the signal, apply an equalizer to the waveform, receive an input identifying one or more measurements to be made on the waveform, select a number of unit intervals (UIs) for a known data pattern, scan the waveform for the known data patterns having a length of the number of UIs, identify the known data patterns as short pattern waveforms, apply a machine learning system to the short pattern waveforms to obtain a value for the one or more measurements, and provide the values of the one or more measurements for the waveform.

Abstract: A test and measurement system includes a machine learning system, a test and measurement device including a port configured to connect the test and measurement device to a device under test (DUT), and one or more processors, configured to execute code that causes the one or more processors to: acquire a waveform from the device under test (DUT),transform the waveform into a composite waveform image, and send the composite waveform image to the machine learning system to obtain a bit error ratio (BER) value for the DUT. A method of determining a bit error ratio for a device under test (DUT), includes acquiring one or more waveforms from the DUT, transforming the one or more waveforms into a composite waveform image, and sending the composite waveform image to a machine learning system to obtain a bit error ratio (BER) value for the DUT.

Abstract: 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.

Abstract: A test and measurement system includes a clock recovery circuit configured to receive a signal from a device under test and to produce a pattern trigger signal, a flash array digitizer having an array of counters having rows and columns configured to store a waveform image representing the signal received from the device under test, a row selection circuit configured to select a row in the array of counters, and a ring counter circuit configured to receive a clock signal, select a column in the array of counters, produce end of row signals, and produce a fill complete signal upon all of the columns having been swept, the fill complete signal indicating completion of the waveform image, an equivalent time sweep logic circuit configured to receive the pattern trigger signal and the end of row signals from the ring counter and to produce the clock signal with a delay to increment a clock delay to the ring counter until the fill complete signal is received, and a machine learning system configured to receive the

Abstract: A test and measurement system includes a test and measurement device, a connection to allow the test and measurement device to connect to an optical transceiver, and one or more processors, configured to execute code that causes the one or more processors to: set operating parameters for the optical transceiver to reference operating parameters; acquire a waveform from the optical transceiver; repeatedly execute the code to cause the one or more processors to set operating parameters and acquire a waveform, for each of a predetermined number of sets of reference operating parameters; build one or more tensors from the acquired waveforms; send the one or more tensors to a machine learning system to obtain a set of predicted operating parameters; set the operating parameters for the optical transceiver to the predicted operating parameters; and test the optical transceiver using the predicted operating parameters.

Abstract: A system for generating images on a test and measurement device includes a first input for accepting a waveform input signal carrying sequential digital information and an image generator structured to generate a visual image using a segment of the waveform input only when two or more sequential codes of digital information match sequential codes carried in the sequential digital information of the segment of the waveform input. A user-defined state-machine comparator may be used to determine which segments of the waveform input signal are used in the image generation.

Abstract: 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.

Abstract: A continuously or step variable passive noise filter for removing noise from a signal received from a DUT added by a test and measurement instrument channel. The noise filter may include, for example, a splitter splits a signal into at least a first split signal and a second split signal. A first path receives the first split signal and includes a variable attenuator and/or a variable delay line which may be set based on the channel response of the DUT which is connected. The variable attenuator and/or the variable delay line may be continuously or stepped variable, as will be discussed in more detail below. A second path is also included to receive the second split signal and a combiner combines a signal from the first path and a signal from the second path into a combined signal.

Abstract: A test and measurement system including a plurality of channels and one or more processors. The one or more processors are configured to cause the test and measurement system to receive, via a first channel of the plurality of channels, a positive side of a reference differential signal pair, receive, via a second channel of the plurality of channels, a negative side of the reference differential signal pair, and produce a reference signal based the reference differential signal pair. A combined signal is received, from a combiner, that is a balanced signal produced from the reference differential signal pair. A de-embed filter is generated based on the reference signal and the combined signal and an additional signal is received from the combiner and an effect of the combiner is removed from the additional signal by applying the de-embed filter to the additional signal.

Abstract: A method determines scattering parameters, S-parameters, for a device under test for a first frequency range. The method includes receiving S-parameters for the device under test for a second frequency range, the second frequency range greater than the first frequency range. Generally, the S-parameters for the device under test for the second frequency range can be determined using known methods. The method further includes measuring an actual response of the device under test, determining a desired signal of the device under test, and determining the S-parameters for the device under test for the first frequency range based the S-parameters for the second frequency range, actual response of the device under test and the desired signal of the device under test.

Abstract: An apparatus configured to acquire S-parameters of a communications channel includes a physical interface configured to transmit and receive signals through a communications channel under test, a processor, configured to execute instructions that, when executed cause the processor to: send a first data pattern from the transmitter through the communications channel at a first data rate; acquire a first waveform corresponding to the first data pattern and determine a first pulse response; calculate a first transfer function from the first pulse response; send a second data pattern from the transmitter through the communications channel at a second data rate; acquire a second waveform corresponding to the second data pattern and determine a second pulse response; calculate a second transfer function from the second pulse response; and combine the first and second transfer functions to determine an S-parameter of the communications channel.

Abstract: An apparatus configured to acquire S-parameters of a communications channel includes a physical interface configured to transmit and receive signals through a communications channel under test, a processor, configured to execute instructions that, when executed cause the processor to: send a first data pattern from the transmitter through the communications channel at a first data rate; acquire a first waveform corresponding to the first data pattern and determine a first pulse response; calculate a first transfer function from the first pulse response; send a second data pattern from the transmitter through the communications channel at a second data rate; acquire a second waveform corresponding to the second data pattern and determine a second pulse response; calculate a second transfer function from the second pulse response; and combine the first and second transfer functions to determine an S-parameter of the communications channel.

Abstract: Disclosed is a mechanism for limiting Intersymbol Interference (ISI) when measuring uncorrelated jitter in a test and measurement system. A waveform is obtained that describes a signal. Such waveform may be obtained from memory. A processor then extracts a signal impulse response from the waveform. The processor selects a window function based on a shape of the signal impulse response. Further, the processor applies the window function to the signal impulse response to remove ISI outside a window of the window function while measuring waveform jitter. The window function may be applied by applying the window function to the signal impulse response to obtain a target impulse response. A linear equalizer is then generated that results in the target impulse response when convolved with the signal impulse response. The linear equalizer is then applied to the waveform to limit ISI for jitter measurement.

Abstract: 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.

Abstract: 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.

Abstract: A test and measurement instrument, including a splitter configured to split an input signal into two split input signals and output each split input signal onto a separate path and a combiner configured to receive and combine an output of each path to reconstruct the input signal. Each path includes an amplifier configured to receive the split input signal and to compress the split input signal with a sigmoid function, a digitizer configured to digitize an output of the amplifier; and at least one processor configured to apply an inverse sigmoid function on the output of the digitizer.

Abstract: A continuously or step variable passive noise filter for removing noise from a signal received from a DUT added by a test and measurement instrument channel. The noise filter may include, for example, a splitter splits a signal into at least a first split signal and a second split signal. A first path receives the first split signal and includes a variable attenuator and/or a variable delay line which may be set based on the channel response of the DUT which is connected. The variable attenuator and/or the variable delay line may be continuously or stepped variable, as will be discussed in more detail below. A second path is also included to receive the second split signal and a combiner combines a signal from the first path and a signal from the second path into a combined signal.

Abstract: Disclosed is a mechanism for limiting Intersymbol Interference (ISI) when measuring uncorrelated jitter in a test and measurement system. A waveform is obtained that describes a signal. Such waveform may be obtained from memory. A processor then extracts a signal impulse response from the waveform. The processor selects a window function based on a shape of the signal impulse response. Further, the processor applies the window function to the signal impulse response to remove ISI outside a window of the window function while measuring waveform jitter. The window function may be applied by applying the window function to the signal impulse response to obtain a target impulse response. A linear equalizer is then generated that results in the target impulse response when convolved with the signal impulse response. The linear equalizer is then applied to the waveform to limit ISI for jitter measurement.

Abstract: A method of employing a Decision Feedback Equalizer (DFE) in a test and measurement system. The method includes obtaining an input signal data associated with an input signal suffering from inter-symbol interference (ISI). A bit sequence encoded in the input signal data is determined to support assigning portions of the input signal data into sets based on the corresponding bit sequences. The DFE is applied to each set by employing a DFE slicer pattern corresponding to each set, which results in obtaining a DFE adjusted waveform histogram/PDF/waveform database graph for each set adjusted for ISI and accurately captures jitter suppression. The DFE adjusted waveform histogram/PDF/waveform database graphs are normalized and combined into a final histogram/PDF/waveform database graph for determining an eye contour of an eye diagram and jitter measurements.