An RF vector signal generator specializes in creating RF signals with analog and digital modulation schemes in formats such as QAM, QPSK, FSK, BPSK, and OFDM. Vector signal generators are commonly used for receiver sensitivity testing. The digital signal generator generates a baseband signal, which is then modulated in amplitude and phase to make the final modulated signal. You can find VSGs in the telecommunications industry, where they play a critical role in testing and evaluating modern communication systems and devices.