The signal generator has the function of signal modulation. What is the
signal modulation? The signal modulation refers to the in the modulating signal,
frequency change inset the LF signal into the HF carrier signal. The the signal
can transfer any information from data to video. The signal modulation can
divide into analog modulation and digital modulation. The analog modulation like
AM and FM are often applied in the broadcast communication; while the digital
modulation is on account of two states, and allow the binary data.