Vector Signal Analysis is the basis for modern RF signal analyzers, and it relies on the fact that RF signal is down-converted to baseband I & Q signals, which are then digitized over a given amount of time. Almost without exception, SignalVu-PC performs math on baseband I & Q signals to produce measurements and display data. This video demonstrates vector signal analysis using SignalVu-PC and an RSA507A Real-Time Spectrum Analyzer. You can also learn more about IQ data at Alan Wolke’s blog here.
SignalVu-PC Primer Vector Signal Analysis