Abstract: A system and method for calculating a bit error rate for a mask is described. For each time during the time duration of the mask, the minimum and maximum voltages of the mask at that time are determined. The maximum bit error rate can be calculated for each time by integrating between those voltages. The maximum bit error rate for all times during the time duration of the mask can be selected as the maximum bit error rate for the mask.
Abstract: A test and measurement system for synchronizing multiple oscilloscopes including a host oscilloscope and at least one client oscilloscope. The host oscilloscope includes a host timebase clock configured to output a clock signal, a host digitizer including a digitizer synchronization clock based on the clock signal, and a host acquisition controller includes a trigger synchronization clock based the clock signal and outputs a run signal to begin an acquisition of an input signal. Each client oscilloscope includes a client timebase clock configured to receive the clock signal from the host timebase clock and output the clock signal, a client digitizer including a digitizer synchronization clock based on the clock signal, and a client acquisition controller includes a trigger synchronization clock based on the clock signal and receives the run signal from the host acquisition controller and begins an acquisition of another input signal based on the run signal.
Type:
Grant
Filed:
May 28, 2015
Date of Patent:
May 16, 2017
Assignee:
Tektronix, Inc.
Inventors:
Barton T. Hickman, Jed H. Andrews, Jeffrey W. Mucha
Abstract: 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.
Abstract: The disclosed technology relates to a probe for use with a test and measurement instrument. The probe includes a digital multimeter or voltmeter with an analog-to-digital converter configured to measure a signal from a device under test and determine a digital measurement from the signal, a controller connected to the multimeter or voltmeter configured to receive the digital measurement from the multimeter or voltmeter, a digital communication interface connected to the controller configured to communicate with the controller, and a communication link connected to the digital communication interface and the analog signal interface to communicate with the test and measurement instrument.
Abstract: A test and measurement probe connection system including an interposer, at least one probe tab connected to the interposer, and a connector that is releasably connectable to the at least one probe tab to measure signals from the interposer.
Abstract: A signal generation system can include an input source configured to provide an input radio frequency (RF) signal, a correction filter calculation (CFC) block configured to determine correction filter parameters, and an automatic level control (ALC) loop configured to provide ALC loop information to the CFC block. The correction filter parameters may be determined based at least in part on the ALC information. The system can also include a predistortion field programmable gate array (FPGA) configured to apply a correction filter to the input RF signal, wherein the correction filter is based at least in part on the correction filter parameters, and an RF output configured to provide an RF output signal.
Abstract: A system for dynamically calibrating operational parameters of a Device Under Test (DUT) includes a signal generator for generating a data pattern, a DUT structured to generate a clock signal, an oscilloscope structured to measure margins of the generated clock signal compared to an eye-diagram produced on the oscilloscope from the data pattern, and a calibration unit. The calibration unit can produce a candidate a jitter value for the signal generator, receive a determination from the oscilloscope whether the data pattern generated with the candidate jitter value causes the DUT to produce the generated clock signal within a pre-determined tolerance level, and modify the jitter value accordingly. The calibration unit may also be further structured to generate voltage swing values.
Type:
Grant
Filed:
July 30, 2015
Date of Patent:
April 11, 2017
Assignee:
Tektronix, Inc.
Inventors:
Ganesh K. Kumar, Krishna N H Sri, Madhusudhan Acharya, Kamlesh Mishra
Abstract: A modularized signal conditioning apparatus system includes at least two slots formed in a coaxial cable. The slots are spaced apart so as to not reduce the measuring performance of the coaxial cable. Slots may be at least 40 mills from one another. In an ESD embodiment, within each slot is an ESD protection component, such as a pair of Shottky diodes coupled between the ground shell and the center conductor of the coaxial cable. Methods of producing modularized signal conditioning apparatus system are also described.
Abstract: A method of preventing inter-system interference while acquiring waveforms in a test and measurement instrument with variation in a device under test system S-parameters. The method includes receiving a waveform from a device under test at the test and measurement instrument, digitizing the waveform, identifying portions of the digitized waveform with different S-parameter characteristics, separating the identified portions of the digitized waveform into different waveforms, and displaying the different waveforms to a user.
Abstract: Embodiments of the present invention provide improved techniques for recovering clock information from data signals. In one embodiment, a general purpose device such as a real-time oscilloscope acquires a data signal. The device takes a derivative of the data signal, then computes the square or absolute of the derivative before applying a bandpass filter. The bandpass filter is a windowing function a spectrum that is wider than the clock, and has a flat top and smooth transitions on both sides. In one embodiment, at Tukey window may be used. The device finds edge crossing times of the filtered result, and applies a phase-locked loop or lowpass filter to the edge crossing times in order to recover a stable clock signal. When the improved techniques are implemented in software, they may be used with any number of different equalizers that are required by various high-speed serial data link systems.
Abstract: A method of evaluating perceptual visual quality (PVQ) of compressed video bit streams in the H.262 or H.264 formats without performing block transforms or prediction decodes I-frames within a group of pictures (GOP). DC and AC coefficients are determined for selected macroblocks within a selected one of the I-frames. Based upon the DC and AC coefficients, the PVQ is calculated.
Abstract: System and methods may allow an operator of a signal measurement instrument to characterize and calibrate a network with unsupported connector types, e.g., not traceable to known standards. Adapters having supported and unsupported interfaces can be used to measure the system responses of networks in a system under test. These measurements can be mathematically cascaded to deduce virtual models that produce an accurate and fully calibrated total system response.
Abstract: A ground-penetrating RADAR-based system can include a transmitter configured to transmit multiple RADAR impulses and a receiver configured to receive a signal comprising return waves generated responsive to the transmitted RADAR impulses. The signal can include a direct wave portion and a reflected wave portion. The system can also include a processing unit configured to analyze the return waves by determining the direct wave portion, fitting the direct wave portion to determine parametric information corresponding to the return waves, determining the reflected wave portion, determining characteristics of the reflected wave portion based on the parametric information, and comparing the determined characteristics against known characteristics.
Abstract: A test and measurement instrument includes a coefficient storage facility coupled to a programmable filter. The coefficient storage facility is configured to store at least two pre-determined filter coefficient sets, and configured to pass a selected one of the at least two pre-determined filter coefficient sets to the filter based on a measurement derived using a compensation oscillator. The measurement may include clock delay and clock skew. In some examples the test and measurement instrument may additionally adjust clock delay and/or clock skew in addition to selecting appropriate filter coefficients.
Abstract: A zero insertion force (ZIF) connector can include a connector housing defining an opening and an interior space for receiving a mating member, multiple LIGA springs positioned within the interior space and configured to apply pressure to the mating member while in a first position, and a locking component to cause the LIGA springs to move to a second position responsive to a user pressing the locking component. The LIGA springs do not apply pressure to the mating member while in the second position.
Type:
Grant
Filed:
November 22, 2013
Date of Patent:
February 14, 2017
Assignee:
TEKTRONIX, INC.
Inventors:
James H. McGrath, Jr., Ira Pollock, David W. Simmen
Abstract: An aspect of the invention includes a system and method for determining a block size and offset for a block artifact. A content is identified. The content can be an image, a frame of video, or any other appropriate content. Edge differences are calculated in each dimension of the content based on the pixel values. The edge differences are filtered. From the filtered edge differences, block attributes, such as block size and offset, can be determined.
Abstract: A test and measurement system including a device under test, an accessory, a controller and a test and measurement instrument. The accessory is connected to the device under test and includes a signal input to receive an input signal from the device under test, a compensation unit configured to apply a compensation signal internal to the accessory, and a signal output to output an output signal read from the device under test. The controller is connected to the accessory and includes one or more receivers to receive the input signal and the output signal from the accessory, and a microcontroller or correction circuit configured to compare the input signal and the output signal and in response to the comparison provide a compensation signal to the compensation unit.