Tektronix, Inc.

Other

Mark L Guenther

Kan Tan

Pavel R Zivny

Scott Thomas Porter

Leslie Hill

Timothy Alfred Nevius

Jarret Zablocki

Richard Thomas Rooney

Fredric Schmidt

Krishna N H Sri

Benjamin A Ward

John C Calvin

Daniel D Carpenter

Manisha D Ajgaonkar

Anuradha V

Ramachandra Cv

Dan Carpenter

G R N Prasanth

Pechluck Pongched

Raghavendran N

Manisha Ajgaonkar

Krishna NH Sri

Prasanth Grn

N Raghavendran

V Anuradha

A method of dynamically determining an oscilloscope noise characteristic includes retrieving a power spectral density (PSD) model of noise from a storage based upon a current configuration of the oscilloscope, generating a representation of any filtering being applied to a waveform generated by a device under test, using the PSD and the representation to produce a modified power spectral density, and using the modified power spectral density to determine a dynamic oscilloscope noise characteristic. A test and measurement instrument has one or more inputs to acquire waveforms from a device under test (DUT), one or more processors to retrieve a power spectral density (PSD) model of noise from a database, generate a representation of any filtering being applied to a waveform generated by the DUT, use the PSD and the representation to produce a modified PSD, and use the modified PSD to determine a dynamic instrument noise characteristic.

Semi-automated oscilloscope noise compensation based on power spectral density characterization

A test and measurement device includes an input for receiving a test waveform from a Device Under Test (DUT), where the test waveform has a plurality of input level transitions, a selector structured to respectively and individually extract only those portions of the test waveform that match two or more predefined patterns of input level transitions of the test waveform, a noise compensator structured to individually determine and remove, for each of the extracted portions of the waveform, a component of a jitter measurement caused by random noise of the test and measurement device receiving the test waveform, a summer structured to produce a composite distribution of timing measurements with removed noise components from the extracted portions of the test waveform, and a jitter processor structured to determine a first noise-compensated jitter measurement of the DUT from the composite distribution. Methods of determining noise-compensated jitter measurements are also disclosed.

Noise-compensated jitter measurement instrument and methods

A method for determining jitter and noise of an input signal. The method includes acquiring one or more uncorrelated waveform records by an acquisition unit of a test and measurement instrument, determining a correlated waveform from the acquired waveform(s), dividing the correlated waveform into unit intervals, dividing an uncorrelated waveform into unit intervals, measuring a timing displacement (t) between the correlated waveform and the uncorrelated waveform for each unit interval to form an apparent-jitter array ([t]), measuring a voltage displacement (V) between the correlated waveform and the uncorrelated waveform for reach unit interval to form an apparent-noise array ([V]), calculating a horizontal shift (t) between the correlated waveform and the uncorrelated waveform for each unit interval to form a compensated edge time array ([t]), and calculating a vertical shift (V) between the correlated waveform and the uncorrelated waveform for each unit interval to form a compensated amplitude voltage array ([V]).

Method for performing joint jitter and amplitude noise analysis on a real time oscilloscope

An emission test system may include at least one controller configured to determine, directly or indirectly, a quantity of diluted exhaust sample in a container at the completion of an emissions test, and to cause additional diluent gas to be added to the container based on the determined quantity.

Emissions test system and method

Embodiments of the invention provide a system and method to measure and represent the measured value of a limit in terms of another measurement, such as clock values or cycles of the system. The system can include, for example, a test and measurement instrument such as an oscilloscope. In another embodiment of the present invention, slew rate de-rated values may be automatically determined through the use of configurable lookup tables.

Computer system for automatically determining slew rate de-rating values

A method for analyzing jitter using a test and measurement instrument includes obtaining a collection of time interval error (TIE) values corresponding to composite jitter of a waveform, optionally decomposing the composite jitter into jitter components that are correlated to the data pattern and components that are uncorrelated to the data pattern, and using a spectral approach to decompose the jitter components into jitter components that are recognizable as deterministic and jitter components that are unrecognizable as deterministic. Thereafter, the jitter components analyzed in the frequency domain are converted back to the time domain, and subtracted from the composite jitter, thereby isolating uncorrelated residual jitter. The uncorrelated residual jitter is decomposed into bounded uncorrelated jitter and random jitter, for example, by integrating a probability density (PDF) function of the residual jitter and analyzing the resulting cumulative distribution function (CDF) curve in Q-space.

Method for decomposing and analyzing jitter using spectral analysis and time-domain probability density

An Arbitrary Waveform Generator (AWG) synthesizes and generates an SSC modulated signal by generating a modulating waveform with a frequency of an SSC modulation frequency, calculating the number of samples per data bit (SPUI) as a ratio of an upsampling frequency to a data rate of a data stream, calculating an amplification factor as the ratio of SSC deviation frequency to data rate of the data stream, generating the array of SSC Edges containing the edge variation with respect to single sample per bit, multiplying the amplification factor to the modulating waveform, generating an array of SSC Edges Upsampled, containing edge variations with respect to an Upsample factor per bit, and multiplying SSC Edges with SPUI; calculating the resultant bit duration SSC Bit Duration as the sum of SSC Edges Upsampled and SPU, and calculating the successive summation of SSC Bit Duration, to get SSC Bit Position.

Apparatus and method for synthesizing and generating an SSC modulated signal

A method and apparatus for decomposing timing jitter on arbitrary serial data sequences. Specifically, in one embodiment according to the present invention, a method is provided of decomposing timing jitter on a signal under test (SUT) comprising an arbitrary serial data stream. The method comprises performing a statistical analysis on a group of measurements, where each measurement comprises a timing jitter value and an associated bit pattern representing the bits falling within an analysis window, said window being successively located at a plurality of positions within the data stream.

Method for decomposing timing jitter on arbitrary serial data sequences

A method and apparatus for representing a complex vector signal by determining representative coordinates for the complex vector signal, wherein at least some of the determined representative coordinates are associated with corresponding reference coordinates; associating each of at least a portion of the determined representative coordinates and corresponding reference coordinates with at least one of a plurality of temporal spans; and selectively processing each of a plurality of temporal spans.

Method and apparatus for representing complex vector data

A method for identifying spectral impulses applies a window filter to an acquired waveform to produce a filtered waveform, and performs an FFT function on the filtered waveform to produce a spectrum of bins. An estimating window is located on the spectrum and centered on a target bin. Bins adjacent to the target bin are excluded and the remaining bins are used to form a noise estimate. The estimate is compared to the target bin and if the result exceeds a threshold value, a spectral impulse is identified.

Method of identifying spectral impulses for Rj Dj separation

A jitter separation apparatus and method, based on spectrum analysis, separates deterministic jitter and random jitter using their spectral properties. Deterministic jitter is periodic and nature and exhibits a spectrum of impulses, whereas random jitter exhibits a broad, flat spectrum. A time domain histogram and a frequency domain histogram of the signal are investigated to obtain jitter components.

Apparatus and method for spectrum analysis-based serial data jitter measurement

A method for representing a modulated signal vector by determining complex coordinates for the signal vector where the complex coordinates define respective locations on a complex plane that is logically segmented into a plurality of regions, and by generating, for each logical region, a respective signal density indicative magnitude value to form a histogram of the logical regions and their respective magnitude values.

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Portland, OR, United States of America

Mark L Guenther