transponder A radio or radar system that is triggered by a received signal. Transponders are important components of communications satellites and consist of a receiver, a frequency converter, and transmitter package. They have a typical output of 5-10 watts, operate over a 36-72 MHz bandwidth in the L-, C-, Ku-, or Ka-band, except for mobile satellite communications. Communications satellites typically have 12-24 onboard transponders, although the Intelsat VI at the extreme end has 50. Related category • SPACECRAFT COMMUNICATIONS AND TRACKING Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |