Abstract: Embodiments of this invention include a test and measurement instrument and associated methods for automatically setting frequency span in a spectrum analyzer. For example, starting with a high reference level, the power level can be automatically measured for each band. If a suitable minimum power is not found in one of the bands, the reference level can be automatically and iteratively decreased until the suitable minimum power is found, or until the most sensitive power level is reached. This assures enough sensitivity to correctly determine the signal power level and not make decisions based on noise. When power on any band is greater than the predefined noise criteria, then the band having the highest power level can be selected, and the center frequency and span for the band measuring the most power can be automatically set.

Abstract: An automatic quadrature network with amplitude and phase detection produces quadrature signals for an input oscillator signal, the quadrature signals being equal in amplitude and having ideal quadrature phase between them. An RC circuit provides one quadrature path, and a CR circuit provides another quadrature path. The outputs from the RC/CR circuits are amplitude detected to produce an amplitude control signal. The outputs also are amplitude limited, and the phase between the limiter outputs is detected to produce a phase control signal. The amplitude and phase control signals are combined to generate respective control signals for the RC/CR circuits to automatically align them so that the quadrature signals are of equal amplitude and ideal quadrature phase.

Abstract: Described are methods of determining imbalance in an IQ modulator. Example methods include applying a set of at least three test signals to the I channel and Q channel to generate an output, then receiving output from a frequency measuring device coupled to the IQ modulator. Some of the set of test signals may be substantially different than other test signals in the set. After the frequency specific output is received, the method measures one or more values and derives the imbalance in the IQ modulator from the measured values. Embodiments also include adjusting parameters of the test signals until a minimum distance is measured. A device is also described, which includes a test signal generator, an output analyzer, and a minimizer structured to cause the test signal generator to generate a set of test signals that cause a distance measured in the output to be a minimum distance.

Abstract: A dF/dT trigger system and method includes instantaneously triggering on a frequency deviation of a data signal, which can be associated with an SSC signal. After receiving a signal at an input terminal of a test and measurement instrument, the signal is low-pass filtered and transmitted to trigger circuitry. When a frequency deviation rate in the filtered signal exceeds or crosses one or more thresholds, a trigger event is produced. Also disclosed is a test and measurement instrument including an input terminal to receive the signal, input circuitry to receive and process the signal, and dF/dT trigger circuitry configured to receive the signal and produce a trigger event when a frequency deviation in the signal exceeds or crosses one or more thresholds.

Abstract: A dual probing tip system uses a slot and rail system to provide variable spacing and lateral and axial compliance of the probing tips mounted on first and second support members. A movable base member is secured on a frame with the base member having a rack of linear teeth and a pair of rails angled toward the front. First and second intermediate carriers each have a slot that engages one of the angled rails. Each of the carriers has stanchions that receive a thumb wheel pinion gear mounted on a shaft. The pinion gear mates with the teeth on the base member for movement of the carriers. Each support member has an axial slot that mated with an axial slot on each one of the carriers. Each support member has a compression spring which allows axial compliance of the support members.

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: A relay fault detection and correction system includes a signal detector structured to measure primary and secondary signals, and generates a fault output signal if the signals appear to be unterminated due to a relay not connecting the signals to the loads. A cycle circuit is structured to cause a relay controller to cycle a potentially under-performing relay between its states a number of times after the signal detector generates the fault output.

Abstract: Computationally efficient methods and related systems, for use in a test and measurement instrument, such as an oscilloscope, optimize the performance of DFEs used in a high-speed serial data link by identifying optimal DFE tap values for peak-to-peak based criteria. The optimized DFEs comply with the behavior of a model DFE set forth in the PCIE 3.0 specification.

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: An apparatus can include a digitizer configured to digitize input data into a plurality of digitized signals, a rasterizer configured to generate a plurality of raster images from the plurality of digitized signals, the rasterizer including a subtractor configured to decrement a pixel intensity counter, a processor configured to manipulate the raster images based on the pixel intensity counter, and a display device configured to display the raster images.

Abstract: A system is described for collecting data records which have been correlated to subscriber, or end user, access network, core network, transport network, and application service information, referred to as end user correlated data records and utilizing those records in a wireless or wireline network to identify and address correctable conditions in a network, such as a wireless or wireline network. The system includes at least one probe in the network which is able to monitor network activity and provide detailed data records on that activity. These data records are sent to a mediation device that correlates those data records with subscriber and/or location data, to create the end user correlated data records. An intelligent application services device takes the end user correlated data records and examines the records to determine if there are any correctable conditions in the network or the end user devices.

Abstract: Waveforms generators include a splitter that splits a digital input signal into a number of split signals each having a split signal frequency bandwidth that is substantially similar to a digital input signal frequency bandwidth. The split signals are mixed with associated digital, harmonic signals to generate a number of digital, mixed signals, which are then converted to analog signals at an effective sample rate that is different from a first order harmonic signal of at least one of the digital, harmonic mixers. A number of analog, harmonic mixers mix the associated analog signals with associated analog, harmonic signals to generate mixed, analog signals. The mixed, analog signals are combined into an output signal having an output signal bandwidth that is greater than a bandwidth of at least one of the number of DACs.

Abstract: An amplitude flatness and phase linearity calibration method for an RF source across a wide frequency bandwidth uses a simple square law diode detector and at least a pair of equal amplitude frequency tones. A baseband generator for the RF source generates the tones, which are applied in series to a correction filter and an up-converter to produce an output RF signal. The tones are stepped across a specified frequency bandwidth, and at each average frequency for the tones a magnitude and group delay is measured as well as a phase for the beat frequency between the tones. The resulting measurements are used to calibrate filter coefficients for the correction filter to assure amplitude flatness and phase linearity across the specified frequency bandwidth.

Abstract: A test and measurement instrument for displaying data including an acquisition system configured to receive an input signal, a processor coupled to the acquisition system and configured to generate a schematic from protocol-specific information within the input signal, and a display coupled to the processor and configured to display the schematic.

Abstract: A design of a medical imaging device may be proven by generating perceptual differences using a model of the medical imaging device and a reference model. The model of the medical imaging device may be changed if the perceptual difference are too large. Perceptual contrast difference summaries may be generated for all generated perceptual contrast differences, or those for a particular time or area.

Abstract: A modular probe assembly for a signal processing instrument has an elongate member extending from a first module of the probe assembly and a cavity recessed in a second module of the probe assembly. The cavity of the second module is structured to receive the elongate member of the first module. A module for the probe assembly may have a first articulating elongate member disposed at an end of a housing of the module. The elongate member extending from a first module of the probe assembly may be inserted into a cavity recessed in a second module, and the first module may be removably joined to the second module.

Abstract: A system can include an input signal source, a local oscillator (LO), and an intermediate frequency (IF) receiver to receive an input signal from the input signal source and an LO signal from the LO. The IF receiver can include a switch to switch between the first and second inputs to provide an output. The IF receiver can generate a calibration signal from the LO signal.

Abstract: Described are systems and methods of determining DC offset voltages in IQ modulators. First, two different DC test voltages are selected for one of the inputs to the IQ modulator. Then, a first test voltage is applied to one input to the IQ modulator while test data is generated by measuring outputs from a set of signals applied to the other input to the IQ modulator. Then the second test voltage is applied and another set of test data generated. From the first and second sets of test data, second-order polynomial functions may be constructed and compared to one another to yield a ratio of power value outputs. Then the DC offset voltages may be determined from the ratio of power value outputs.

Abstract: A device can include a radio frequency (RF) signal input, a local oscillator (LO) signal input, a mixer to receive the RF signal and LO signal and translate a frequency of the RF signal based on the LO signal, a strobe pulsing component to provide a timed strobe pulse, and a second mixer to receive a leakage signal, LO signal, and timed strobe pulse, and also to translate a frequency of the leakage signal to baseband. The device can also include a coupling component configured to allow the leakage signal to pass between the mixers. An output signal output can provide a measured value of the leakage signal.