Modulator is also called radio frequency modulator. The modulator of television is full name of adjacent modulator. Modulators are mainly used in cable television room. There are many types of modulators, because some televisions have different formats, so the modulators can be divided into PAL modulators, SECAM modulators, and NTSC modulators. But generally speaking, it can be divided into digital modulators and analog modulators. Of course, there are many small categories in these two categories. Modulators are now widely used in various types of satellite television systems, residential closed-circuit systems and cable television systems.