National Instruments Corporation

Stephen L Dark

Christopher J Behnke

Daniel J Baker

Johnathan R W Ammerman

Robert E Dye

Dustyn K Blasig

Brent C Schwan

Neil S Feiereisel

Taylor L Riche

Mary E Fletcher

Christopher N White

Julian G Valdez

Stephen R Loftus-Mercer

Johnathan Rw Ammerman

Johnathan RW Ammerman

Embodiments are described of devices and methods for processing a signal using a plurality of vector signal generators (VSGs). A digital signal may be provided to a plurality of signal paths, each of which may process a respective frequency band of the signal, the respective frequency bands having regions of overlap. The gain and phase of each signal path may be adjusted such that continuity of phase and magnitude are preserved through the regions of overlap. The adjustment of gain and phase may be accomplished by a complex multiply with a complex calibration constant. The calibration constant may be determined for each signal path by comparing the gain and phase of one or more calibration tones generated within each region of overlap. Each signal path may comprise a VSG to convert the respective signal to an analog signal, which may be combined to obtain a composite signal.

Spectral stitching method to increase instantaneous bandwidth in vector signal generators

Methods and systems are disclosed for using a single receiving device, such as a single VSA, to capture and digitize multiple time-domain acquisitions of a repeating signal at different center frequencies, to create a single time-domain waveform having a bandwidth greater than the real-time instantaneous bandwidth of the receiving device. Specifically, one or more signal processing paths may process the multiple digitized acquisitions of the repeating signal, either sequentially or in parallel, such that the processed acquisitions may be aggregated into a representation of one or more repetitions of the repeating signal.

Time sequenced spectral stitching

Various embodiments are described of devices and associated methods for processing a signal using a plurality of vector signal analyzers (VSAs). An input signal may be split and provided to a plurality of VSAs, each of which may process a respective frequency band of the signal, where the respective frequency bands have regions of overlap. Each VSA may adjust the gain and phase of its respective signal such that continuity of phase and magnitude is preserved through the regions of overlap. The correction of gain and phase may be accomplished by a complex multiply with a complex calibration constant. A complex calibration constant may be determined for each VSA by comparing the gain and phase of one or more calibration tones generated with each region of overlap, as measured by each of the VSAs.

Spectral stitching method to increase instantaneous bandwidth in vector signal analyzers

System and method for creating a graphical program. A first replication structure may be included in a graphical program, where the first replication structure specifies replication of any graphical program code inside the first replication structure. First graphical program code may be included inside the first replication structure. An implementation of the graphical program may be automatically generated, including generating multiple instances of an implementation of the first graphical program code within the implementation of the graphical program. Executing the graphical program may include executing the multiple instances, e.g., concurrently and/or serially.

Replication structure in a graphical programming language

The first and second outputs of a signal generation system are coupled to the first and second inputs of a signal digitizing system via respective electrical conductors. A controller directs the generation system to generate a first calibration signal, and the digitizing system responsively captures a first set of vector samples. The conductors are then reconfigured so they connect the first and second outputs of the generation system respectively to the second and first inputs of the digitization system. The controller then directs the generation system to generate a second calibration signal, and the digitizing system responsively captures a second set of vector samples. The controller or other processing agent computes gain and/or phase impairments using the first and second vector sample sets. Digital filter parameters may be computed based on the computed impairment(s), and used to correct the impairment(s) of the generation system and/or the digitizing system.

IQ baseband matching calibration technique

Systems and methods for measuring transmitter and/or receiver I/Q impairments are disclosed, including iterative methods for measuring transmitter I/Q impairments using shared local oscillators, iterative methods for measuring transmitter I/Q impairments using intentionally-offset local oscillators, and methods for measuring receiver I/Q impairments. Also disclosed are methods for computing I/Q impairments from a sampled complex signal, methods for computing DC properties of a signal path between the transmitter and receiver, and methods for transforming I/Q impairments through a linear system.

Computing I/Q impairments at system output based on I/Q impairments at system input

Communication devices and associated methods for reducing I/Q impairments in signals used by the communication devices are described. A transmitter device may perform filtering (or matrix multiplication) on digital I and Q signals to pre-correct them before converting them into analog I and Q signals. The pre-correction may pre-compensate for I/Q impairments which have not been introduced yet, but which will subsequently be introduced during digital-to-analog conversion, I/Q modulation, or other processing that occurs to produce a transmission signal from the original digital I and Q signals. A receiver device may receive a transmission signal, produce digital I and Q signals from the received signal, and perform filtering on the digital I and Q signals to correct I/Q impairments at a plurality of frequency offsets.

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Austin, TX, United States of America

Stephen L Dark