Frequency converters are used to shift a signal from one center frequency to another, even down to "zero frequency" (or baseband). They are found in almost all receivers and transmitters as well as repeaters and frequency multiplexers. The main system blocks consist of frequency synthesizers (phase locked oscillators), frequency mixers, amplifiers and filters. Frequency conversion can be coherent (i.e. phase locked to a central frequency standard) or incoherent, depending on the application. Frequency converters can be integrated into a complete radio system or as stand-alone units for use in modular systems (e.g. satellite ground stations, channel multiplexers, etc.).

Baseband and single-sideband frequency converters rely on "vector" conversion using an I,Q mixer and a synthesized local oscillator. These converters can be designed for upconversion and downconversion. Common stand-alone applications include baseband-to-IF conversion and frequency division multiplexing systems.

Repeaters are often used to increase radio coverage over a defined area. They receive a signal and, using a frequency converter, rebroadcast the same signal on a different center frequency. They are found in all types of communication – space ("bent-pipe" transponders for broadcasting, telecom), telephony (both backhaul and mini base stations), data (e.g. WiFi, WiMax, etc.), broadcasting, amateur radio, emergency communications, etc. and are useful in environments where radio communication is difficult (remote locations, urban canyons, mountainous regions, indoor environments, etc.). Come to us with your special radio communication requirements.