A digital down-converter (DDC) converts a digitized, band limited signal to a lower frequency signal at a lower sampling rate in order to simplify the subsequent radio stages. The process preserves all the information in the original signal less that which is lost to rounding errors in the mathematical processes. The input and output signals can be real or complex samples. Often the DDC converts from the raw radio frequency or intermediate frequency down to a complex baseband signal.

Acquitek downconverters have frequency coverage 100Khz – 27GHz , with real time analysis bandwith up to 160MHz (0Hz IF).