Digital and analog systems need an interpreter in order to understand each other. and that's where the modem (short for Modulator DEModulator) comes.

The remote sensing satellite earth station is composed by antenna, feed subsystem , servo subsystem, receiver, station manage subsystem, modulator, demodulator, recorder and quick view equipment.

This paper designed a full digital modulator and a full digital demodulator for the millimeter wave communication machine based on the soft radio theory.