Abstract: Embodiments of the invention include an apparatus and method for displaying trigger frequency on a display of a test and measurement instrument. During each of a series of equal time intervals, a number of trigger events are counted. Each trigger event count is associated with a corresponding logical column of a trigger display window. The trigger event counts are written to memory locations associated with the corresponding logical columns of the trigger display window. Trigger frequency logic generates multiple trigger frequency indicators based on the trigger event counts. The trigger frequency indicators are displayed in the trigger display window to quickly and efficiently convey trigger density information to a user of the test and measurement instrument. The apparatus includes jitter reduction logic to reduce or eliminate unwanted jitter related to the trigger frequency indicators.

Abstract: An improved arbitrary waveform generator has a waveform memory for storing digitized waveforms, a waveform playout for playing out desired ones of the digitized waveforms as analog waveforms and a sequencer for controlling the waveform playout, the sequencer providing indications of the desired waveform for playout and a desired starting sample position for the desired waveform. The sequencer includes a tracking mechanism for the desired waveform so that the desired waveform is phase coherent when playout is interrupted and restarted later according to programming of the sequencer.

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: Described are systems and methods of estimating a Signal-to-Noise (S/N) ratio of an input channel carrying a QAM signal. A Modulation Error Ratio (MER) is calculated for the input QAM signal, but uses only the centermost error values of a constellation of the input QAM signal in generating this modified MER. The modified MER accurately represents the S/N ratio of the input channel carrying the QAM signal. In this way the S/N ratio may be accurately determined using only the received I and Q components of the modulated QAM input signal itself.

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: Coherent optical signal processing is performed in a coherent receiver (or diagnostic/testing apparatus) that converts an amplitude and/or angle-modulated optical signal into two electrical signals. A simple receiver can only detect one phase of the signal and only the polarization that is aligned with a local oscillator laser polarization. To detect both phases and both polarizations, two sets of two interferometers, one each with a ?/2 phase shift are required. Coherent optical signal processing methods, apparatus, techniques, etc. are disclosed that include individual components comprising a polarization combiner, a Savart device and photodetection apparatus with substantially reduced temperature and alignment sensitivity operating in optical communication systems and/or subsystems. The various embodiments can be used alone or in such combinations to provide improved coherent optical signal processing in a receiver.

Abstract: Embodiments of this invention provide enhanced triggering capabilities such as frequency and phase triggering in a test and measurement instrument, such as a Real-Time Spectrum Analyzer (RTSA) or oscilloscope. A test and measurement instrument can include input terminals to receive RF signals, an ADC to digitize the RF signals, a digital downconverter to produce I and Q baseband component information, and a power detector to determine a power level using the I and Q information. A comparator compares the power level received from the power detector with a user-definable power threshold, and produces a logic signal for enabling one or more phase or frequency demodulators. The one or more demodulators produce IQ-based time-domain traces derived from the I and Q component information when the power level determined by the power detector exceeds the power threshold. Trigger circuitry is configured to trigger on an event responsive to a delayed trigger enable signal.

Abstract: A signal generator produces a victim signal having crosstalk emulation by filtering and combining a victim signal waveform record file and an aggressor signal waveform record file generated using parameters selected by a user. A signal channel or a cascaded signal channel is characterized using one or more S-parameter arrays. The S-parameter array or arrays represent a mixed-mode multiple-port device under test. Coefficients of a NEXT filter, a FEXT filter and a forward transmission filter are derived from selected S-parameters of the S-parameter array. The aggressor signal is filtered individually by the NEXT and FEXT filters. The victim signal is summed with the filtered aggressor signal from the NEXT filter with the resulting summed signal being filtered by the forward transmission filter. The filtered signal from the forward transmission filter is summed with the filtered aggressor signal from the FEXT filter to generate a victim signal having crosstalk emulation.

Abstract: An electrical contact assembly has a plurality of formed elongate closed seam tubular elements attached to a carrier with each of the elongate tubular elements attached to the carrier via a tab. Scored creases are formed in the tabs for separating the elongate tubular elements from the assembly and scored creases are formed in the carrier for defining carrier strips. The carrier strip had a plurality of grouped elongate tubular elements. The electrical contact assembly is placed in a crimping die where at least one or more wires are inserting into selected elongate tubular elements. Pressure is applied to least one or more of the selected elongate tubular elements to produce bulk material deformation along a substantial portion of the elongate tubular elements to crimp the elongate tubular elements to the wires as electrical contacts.

Abstract: A probing tip for a signal acquisition probe has a non-conductive substrate compatible with thin or thick film processing having opposing horizontal surfaces and side surfaces with two of the side surfaces converging to a point. A contoured probing tip contact is formed at the converging point on the non-conductive substrate with the probing tip contact having first and second intersecting arcuate surface. Electrically conductive material is deposited on the countered probing tip contact using thin or thick film processing for providing electrical contact to test points on a device under test. A resistive element is formed on the non-conductive substrate using thin film processing that is electrically coupled to the probing tip contact and to an input of an amplifier formed on an integrated circuit die mounted on the non-conductive substrate. The output of the amplifier is coupled to a transmission structure formed on a second non-conductive substrate.

Abstract: An apparatus and method for triggering an oscilloscope is disclosed. The oscilloscope is configured to process a first signal in a first domain and a second signal in a second domain. The method includes choosing a different domain for processing each of the first and second signals, respectively. A desired trigger type is selected for one of the chosen domains. The first and second signals are acquired in response to an occurrence of a trigger of the selected trigger type. The first and second signals are processed according to the selected different chosen domains. The method may also include displaying a result of said processing on a display screen.

Abstract: A test and measurement instrument provides for increased transient event detection by adjusting data sampling periods. The test and measurement instrument includes a data sampler for acquiring first sampled data and a data processor structured to process the first sampled data. The data processor operates during a first data processing period. Also included in the instrument is a sample time adjustor structured to allow a user to select a time for the data sampler to acquire second sampled data. The time for the data sampler to acquire the second sampled data occurs during the first data processing period. The time for acquiring the second sampled data may be determined by generating a probability distribution function, then applying the distribution function to the available times during the first data processing period that the second sample data may be collected. Methods of use of the test and measurement instrument are also provided.

Abstract: A machine-implemented method can include receiving a common input signal over M parallel time-interleaved (TI) analog to digital converter (ADC) channels, determining a multiple-input, multiple-output finite impulse response (FIR) filter structure for correcting bandwidth mismatches between the M parallel TIADC channels, and providing a common output signal comprising TI data corresponding to the M parallel TIADC corrected channels.

Abstract: A frequency mask trigger capable of triggering based on a logical combination of two or more areas of a frequency mask transforms a frame of digital data representing an input signal into a frequency spectrum having a plurality of frequency bins, with each frequency bin having a power amplitude value. A frequency mask is defined having a plurality of reference power levels, one reference power level being associated with each frequency bin. Two or more areas of the frequency mask are defined, with each mask area corresponding to one or more of the frequency bins. A violation status is determined for each mask area by comparing all of the power amplitude values within each mask area to the associated reference power level. If any of the power amplitude values within the mask area violates the associated reference power level, then the entire mask area is deemed to be violated. A trigger signal is generated when a logical combination of the violation statuses of the mask areas is satisfied.

Abstract: Systems and methods for Long Term Evolution (LTE) interface correlation are described. In some embodiments, a method may include receiving a first message, the first message having been intercepted over an air (Uu) interface of an LTE network (e.g., probed via a Common Public Radio Interface (CPRI) between an Evolved-Universal Terrestrial Radio Access Network (UTRAN) Node B (eNB)'s remote radio head and baseband processing unit), the first message having a first identifier. The method may also include receiving a second message, the second message having been intercepted over the S1 interface between the eNB and a Mobility Management Entity (MME) within an Evolved Packet Core (EPC) portion of the LTE network within a given time window from the first message, the second message having a second identifier. The method may further include correlating the first and second messages in response to a match between the first and second identifiers.

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: Disclosed is a test and measurement instrument that includes a signal input structured to receive a modulated radio frequency (RF) signal under test and a demodulator structured to extract a digital signal from the received modulated RF signal. The extracted digital signal has a measurable parameter. The instrument also includes a display controller structured to display the extracted demodulated signal at one of at least two different intensities based on the measured parameter of the digital signal. In other embodiments the signal need not be an RF signal. Methods of operation are also described.

Abstract: A system can include a first radio frequency (RF) port, a second RF port electrically coupled with the first RF port, a direct current (DC) port, and a bias tee incorporated into a substrate. The bias tee can include multiple capacitors that are each integrated as a catch pad with a layer of the substrate. The bias tee can also include an inductor at least partially integrated with a layer of the substrate.

Abstract: A device and method of re-sampling a plurality of S-parameters for serial data link analysis is disclosed. The method includes storing a plurality of S-parameters sets, each S-parameter set being associated with a subsystem and having associated impulse responses and a time interval. An increased time interval is determined based on the time interval associated with each S-parameter set. The impulse responses are zero filled in each S-parameter set to maintain any wrapped ripples and increase the time interval. A plurality of resampled S-parameter sets are generated with a finer frequency resolution to cover the increased time interval.