Vector signal analyzer: Difference between revisions

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===DSP and display stage===

Once the signal is digitized, it is separated into [[quadrature phase|quadrature]] and in-phase components ([[I/Q data]]) using a quadrature detector, which is typically {{cn|date=February 2024}} implemented with a [[Hilbert transform#Discrete Hilbert transform|discrete Hilbert transform]]. Several measurements are made and displayed using these signal components and various [[digital signal processing|DSP]] processes, such as the ones below.

==== Signal spectrum from FFT ====

{{main|Fast Fourier transform}}

A [[fast fourierFourier transform|FFT]] is used to compute the frequency spectrum of the signal. Usually there is a [[window function|windowing function]] option to limit [[spectral leakage]] and enhance frequency resolution.<ref>Keysight [https://stgwww.keysight.com/cn/zh/assets/7018-02679/technical-overviews/5990-6405.pdf], ''Keysight Vector Signal Analysis Basics'', Published September 30, 2019.</ref> This window is implemented by multiplying it with the digitized values of the sample period before computing the FFT.

==== Constellation diagram ====

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==References==

* [httphttps://www.ewh.ieee.org/r2/baltimore/Chapter/Comm/VSA_COMSOC.pdf Communications Systems Analysis Using Hardware and Software-Based Vector Signal Analyzers]

===Footnotes===