A test and measurement instrument has an input to receive a signal under test having a repeating pattern. one or more analog-to-digital converters (ADC) to sample the signal under test at a sample rate over many repeating patterns to digitize the signal, one or more processors configured to execute code to cause the one or more processors to: recover a clock from the sampled signal under test, use the clock to generate an original pattern waveform, interpolate and resample from the original pattern waveform to generate an evenly time-spaced pattern waveform, apply an equalizer to the evenly time-spaced pattern waveform to produce an equalized pattern waveform, interpolate and resample from the equalized pattern waveform to produce a new waveform having equalized samples at sample times of the sampled signal under test, recover an updated clock from the new waveform, and use the updated clock to produce an updated waveform.

A test and measurement accessory has an input to receive an input signal from a device under test (DUT), a pilot signal generator to generate a pilot signal, an E/O converter to convert the input signal and the pilot signal to a combined optical signal, an O/E converter to convert the combined optical signal to a combined electrical signal, a signal separator to separate the pilot signal from the combined electrical signal, an amplitude detector to determine amplitude of the separated pilot signal, and circuitry to adjust a gain of a signal path using the amplitude. A test and measurement accessory has an input to receive an input signal from a DUT, an E/O converter to produce an optical signal, an optical splitter to split the optical signal into a feedback portion and a remaining portion, a feedback photodiode to produce a feedback electrical signal to adjust the optical signal.

A test and measurement instrument including a splitter configured to split an input signal into at least two split signals, at least two harmonic mixers configured to mix an associated split signal with an associated harmonic signal to generate an associated mixed signal, at least two digitizers configured to digitize the associated mixed signal, at least two MIMO polyphase filter arrays configured to filter the associated digitized mixed signal of an associated digitizer of the at least two digitizers, at least two pairs of band separation filters configured to receive the associated digitized mixed signals from each of the MIMO polyphase filter arrays and output a low band of the input signal and a high band of the input signal based on a time different between the at least two digitizers and a phase drift of a local oscillator, and a combiner configured to combine the low band of the input signal and the high band of the input signal to form a reconstructed input signal.

A sensor detects the rotation of a component (object) of a vehicle in a non-contact manner, and generates a differential signal according to the rotation. Two comparators have different hysteresis characteristics. At both edges of one signal that is an output of one of the comparators, if a signal of the other comparator is not at the same level, it is determined that a distance (gap) between an object and the sensor is within a predetermined range in which the differential signal is effective.

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 waveform display device displays first and second waveform data whose value changes with respect to a time axis. Based on a first point on the first waveform data, a second point on the second waveform data which is in a correspondence with the first point is obtained. Correspondence data indicating a correspondence between the first point and the second point is generated. Then, based on the correspondence data, the first and second waveform data is displayed in a manner such that a predetermined point (a reference point) on the first waveform data and a point on the second waveform data which is in a correspondence with the reference point overlap one another on a time axis.

A device is disclosed that includes a control circuit, a scope circuit and a time-to-current converter. The control circuit configured to delay a voltage signal for a delay time to generate a first control signal, and to generate a second control signal according to the first control signal and the voltage signal. The scope circuit configured to generate a first current signal in response to the second control signal and the voltage signal. The time-to-current converter configured to generate a second current signal according to the first control signal and the voltage signal.

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.

Embodiments of the invention include a test and measurement instrument including a test signal input and a sampler coupled to the test signal input to generate a sampled test signal. The instrument also includes a noise reduction system that includes an additional oscillator coupled to the sampler and structured to generate a sampled oscillating signal, as well as a phase detector coupled to the sampled oscillating signal for measuring noise introduced by the sampler. The noise reduction system further includes a phase corrector coupled to the phase detector for removing the measured amount of noise from the sampled test signal. Methods of noise detection are also described.

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.