Abstract: An advanced trigger circuit includes two trigger decoders, each triggering on one of respective pluralities of continuous-time trigger events. In one embodiment, a programmable timer begins timing in response to an output signal of the first trigger decoder and generates an end-of-time signal at the expiration of its time period. A reset circuit resets the first trigger decoder if the second selected continuous-time trigger event failed to occur before the end-of-time signal was generated. In another embodiment, a reset decoder generates a reset signal in response to an occurrence of a selected continuous-time trigger event. The reset circuit is responsive to the reset signal for resetting the first trigger decoder if the second selected continuous-time trigger event failed to occur before the reset signal was generated. In other embodiments, the advanced trigger circuit triggers on a serial lane skew violation or on a beacon width violation.

Abstract: A terminal element for fiber optic communication has an elongated body defining a body axis and having a first end from which an optical fiber extends along the body axis. The body has a second end with an angled surface offset at an angle from the body axis. The fiber extends through the length of the body, and terminates at a fiber end surface flush with the angled surface. A lens element is positioned adjacent to the angled surface. The fiber may be hermetically sealed to the body at a position away from first end, and may be sealed with a flexible material at the first end.

Abstract: A signal acquisition probing system uses a micro-cavity laser to acquire an electrical signal from a device under test. The micro-cavity laser has a VCSEL gain medium and an electro-optic optical resonant cavity. The micro-cavity laser is pumped by an external laser source and generates a frequency modulated optical signal derived from the device under test electrical signal creating an electro-magnetic field distribution in electro-optic material in the micro-cavity laser that overlaps the optical path of the optical signal propagating in the electro-optic material. The frequency modulated optical signal is coupled to an optical receiver which converts the frequency modulated optical signal to an electrical signal. The electrical signal is coupled to measurement test instrument for processing and displaying of the electrical signal.

Abstract: A display of code domain power (CDP) for a code domain multiple access (CDMA) signal having multiple spreading factors is in the form of a three-dimensional graphic having as axes code domain power, code index and spreading factor to provide a visual indication of both power and spreading factor for active codes. Sub-codes of base codes may be identified by any suitable means, such as highlighting. Sub-codes may be suppressed and the power level of the base codes adjusted accordingly to represent the total power of the active codes.

Abstract: A method of measuring relative channel delay between components of a video signal includes removing a local mean from each of the pair of input component signals and cross-correlating the resulting pair of input component signals. A mean is removed from the cross-correlation and a centroid for the cross-correlation is found within a region bound by nearest zero-crossing to a peak in the cross-correlation. The centroid is then converted to a delay time as a function of sample rate after removing a sample offset. Also a normalized peak value of the cross-correlation provides a figure of merit for the probable accuracy of the delay measurement.

Abstract: A luminance qualified vector display device provides a vector display that is gated by a specified luminance range. In one implementation three luminance gates may be used, one for luminance levels above a specified high luminance threshold, a second for luminance levels below a specified low luminance threshold, and a third for luminance levels between the specified high and low luminance thresholds. Also the luminance thresholds for the medium luminance range may be separately adjusted to overlap the high and low luminance ranges respectively. Each luminance qualified vector display may be displayed separately, may be overlaid for display using a different color for each luminance range, or may be displayed in different quadrants of a display device or window together with the normal, non-luminance qualified, vector display.

Abstract: A differential measurement probe has spring loaded, double cushioned probe assemblies and a pressure sensors disposed in a housing. The pressure sensors forms an electrical switch having an electrical AND function for passing an activation signal to a EOS/ESD protection control module in response to axial movement of the housing relative to the probe assemblies. First compressive elements produces first pre-loaded compressive forces and increasing compressive forces on the probe assemblies and second compressive elements produces second pre-loaded compressive forces and increasing compressive forces on the probe assemblies subsequent to the first increasing compressive forces on the probe assemblies. An adjustment member allows variable spacing of the differential probing tips.

Abstract: A differential termination and attenuator network receives a differential input signal having a DC common mode voltage. The network circuit includes input termination resistors coupled in parallel with corresponding resistive attenuator circuits. A monitoring circuit coupled to input nodes of the network generates an output signal representative of the combination of a DC common mode voltage on the input nodes and an applied termination voltage. A control circuit receives the output signal from the monitoring circuit and the applied termination voltage and generates a scaled termination voltage and a scaled compensation voltage and drive currents. The scaled termination and compensation voltages and drive currents provide DC currents through the input termination resistances and the attenuators for nulling DC currents at the network input nodes and provides a DC common mode voltage output from the attenuators for optimizing the dynamic range of a differential measurement amplifier.

Abstract: A differential termination and attenuator network having an internal common mode termination voltage generator includes first and second termination resistors coupled in parallel with corresponding resistive attenuator circuits. A monitoring circuit coupled to input nodes of the network generates an output signal representative of the combination of a DC common mode voltage on the input nodes and an internal termination voltage. A control circuit generates scaled termination and compensation voltages and associated drive currents using the internal termination voltage and the monitoring circuit output signal. The scaled termination voltage and the scaled compensation voltage operate on the differential termination and attenuation network to optimize the dynamic range of a differential amplifier connected to the first and second attenuator outputs and null the DC currents at the input of the network.

Abstract: A calibration system for calibrating a linearity corrector using the sum of filter products is proved, along with a method of calibrating the linearity corrector. The calibration system includes a first and second signal generator for introducing test signals into a signal processing system, such as an ADC. An acquisition memory and processor are provided for acquiring and analyzing the output of the signal processing system and then programming the filter coefficients into the linearity corrector. The method of calibration analyzes acquired intermodulation and harmonic components from the signal processing system and then finds the amplitude and phase response for the filters. The amplitude and phase response is then used to determine a set of filter coefficients.

Abstract: The invention is a method and apparatus for a probe tip contact for electrically coupling a substrate to a probe tip. The apparatus, in one embodiment, comprises a wrap-around contact that is precision formed utilizing a hydroform tool and brazed to a surface of a substrate. In another embodiment, the apparatus comprises a contact flange, a mounting flange extending from a first edge of the contact flange in an orientation substantially perpendicular to the contact flange, and a substantially circular indentation formed in the contact flange adapted for accommodating movement of said probe tip relative to said substrate.

Abstract: A differential termination and attenuator network having an automated common mode termination voltage generator includes first and second termination resistors coupled in parallel with corresponding resistive attenuator circuits. A monitoring circuit coupled to input nodes of the network generates an output signal representative of the combination of a DC common mode voltage on the input nodes and an adjustable termination voltage. A control circuit generates scaled termination and compensation voltages and associated drive currents using the adjustable termination voltage and the monitoring circuit output signal. The scaled termination voltage and the scaled compensation voltage operate on the differential termination and attenuation network to optimize the dynamic range of a differential amplifier connected to the first and second attenuator outputs.

Abstract: A multiple channel signal acquisition device wherein each channel performs a respective rasterization process to provide respective waveform imagery, the respective waveform imagery having a display parameter reduced at a decay rate, the respective waveform imagery being propagated towards an adjacent input channel for combination, the combined image being propagated towards each remaining channel for combination into a final waveform image for display.

Abstract: A method of creation/editing masks/waveforms for an instrument invokes a mask editor from an application running on the instrument. A context or signal waveform displayed in the application is transferred as a reference to a mask editor graphic display together with an unrelated current mask, which may be a previously existing mask or a default mask. The current mask is edited with respect to the reference to define a new mask, such as by changing the positions of points, adding points or deleting points that define the current mask. Then the mask editor is exited and the application recalled, with the new mask being applied to the context in the application.

Abstract: An FFT accelerated display mode for a spectrum analyzer processes time domain samples in increments as they are received until a complete measurement frame of samples is processed to provide a desired frequency resolution. After a first set of time domain samples is received, a spectrum analysis display is provided having a coarse frequency resolution. Then the spectrum analysis display is updated at intervals as more and more time domain samples are received until the complete measurement frame is processed, providing the desired frequency resolution for the spectrum analysis display.

Abstract: An apparatus and method for constraining an amplitude range parameter associated with the acquisition and display of a signal under test (SUT) acquires samples of the SUT that are constrained according to the amplitude range parameter to generate a stream of acquired samples representing a constrained SUT. A controller generates a display signal suitable for use by a display device that includes constrained SUT waveform imagery visually cooperating with amplitude segment delineators. The controller adapts the number of amplitude segment delineators in response to the amplitude range parameter.

Abstract: A video field rate persistence is provided for a video waveform display where multiple video components are displayed simultaneously, one component being updated per field interval. A persistence count is assigned to each pixel in a circular field buffer which is divided equally into a number of sub-buffers representing a portion of a display raster, one for each component. The persistence count is updated for each update of the circular field buffer with the pixel values being maintained until the persistence count equals a maximum value, at which point the pixel values for that component are updated with new pixel values. In this manner the display pixels for each component are updated every X video fields and are maintained at their prior values between updates to provide a flicker free display without temporal separation.

Abstract: A high frequency sweep generator uses a DDS-PLL method for frequency sweep over wide frequency spans. A digital sweep generator produces a linear ramp signal using DDS techniques that is applied to a coarse tuning port of a high frequency tunable oscillator, such as a YIG tunable oscillator (YTO). A PLL has as inputs an accurate linear swept frequency sinusoid from a DDS and a linear swept frequency output signal from the YTO to produce an error correction signal that is applied to a fine tuning port of the high frequency tunable oscillator. The error correction signal compensates for any non-linearities introduced into the linear swept frequency output signal by the high frequency tunable oscillator.

Abstract: A multi-instrument triggering system includes in each instrument trigger system a system ready line for coupling an internal ready signal to an external port. A multi-instrument trigger bus cable connects the external ports, trigger event outputs and trigger event inputs of multiple instruments together in such a way as to enable the trigger generators in the instruments when all instruments are ready to receive a trigger event. When enabled, a coordinated trigger is generated in response to an internal trigger event from at one of the instruments. The coordinated trigger is coupled via the multi-instrument trigger bus cable as the trigger event to trigger all instruments in synchronism.

Abstract: A wide dynamic range vector data raster display of a waveform image is obtained by using a small matrix of pixels from a source frame buffer containing waveform image data to calculate a value for each pixel on a target display. Any of several algorithms may be used for this transform function, such as the unsharp masking (USM) algorithm used in digital photography. This results in increasing the dynamic range of the displayed waveform image over simple pixel-by-pixel intensity mapping.