National Instruments Corporation

Johnathan R W Ammerman

Stephen L Dark

Daniel J Baker

Cary Paul Butler

Daniel S Wertz

Andrew J Hinde

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

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

A system and method for synchronizing a plurality of receivers. A tone from a signal generator is swept over a frequency band. A power splitter splits the tone into a plurality of resultant tones that are supplied to the respective receivers. For each receiver, a relative frequency response (including amplitude and phase responses) is measured between the receiver and a master receiver. A linear approximation to the phase response is computed. A digital filter is custom designed for the receiver to compensate for non-uniformity of the amplitude response and for deviations of the phase from the linear approximation. After applying the digital filter, further adjustments are made to remove the time delay corresponding to the linear approximation, e.g., by appropriately configuring a fractional resampler, by adjusting a numerically-controlled oscillator, and/or, by adjusting sample clock phase.

Synchronizing receivers in a signal acquisition system

An arbitrary waveform generator including a digital signal procession unit and a memory. The digital signal processing unit may be configurable to interconnect a plurality of processing components in different configurations to process data received from the memory and perform one of a plurality of different functions to compute or enhance waveforms without having to store complex waveform data in the memory. In a first configuration, the digital signal processing unit may perform digital up-conversion functions on received waveform data to generate enhanced waveform data, and in a second configuration may perform data interpolation functions to generate enhanced waveform data. In a third configuration, the digital signal processing unit may receive data comprising attributes of a waveform from the memory and perform hardware-controlled arbitrary waveform generation functions. In a fourth configuration, the digital signal processing unit may receive information from software and perform software-controlled arbitrary waveform generation functions.

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Spokane, WA, United States of America

Johnathan R W Ammerman