How Does Satellite Radio Work With an FM Receiver?

FM transmitters use capacitors and inductors to produce radio signals.

Satellite radio customers who lack a built-in satellite-ready stereo system may opt for an FM modulator. This device uses a series of technology products to convert satellite radio signals into standard FM transmission accessible to any radio.

Satellite Radio

The satellite radio receiver gets a signal from the radio service provider's orbiting satellite. The receiver uses proprietary circuitry to translate the received stream of binary code into electronic signals. The receiver then feeds these signals to an attached or built-in FM transmitter.

FM Transmitter

The FM transmitter accepts electronic input from the satellite receiver. FM transmitters use a series of small capacitors and inductors to translate the signals into radio waves. The transmitter then emits the low-power radio waves for the car's built-in radio antenna to pick up. On some models, a switch allows the user to adjust the frequency of the radio waves to avoid interference with other FM broadcasts.

Considerations

The frequency modulation, or FM, spectrum of radio bands ranges from 88 megahertz to 108 megahertz. The electronics website Ramsey Electronics notes that the Federal Communications Commission restricts the range of FM modulators to about 10 feet.

References

• Crutchfield: Satellite Radio FAQ
• Elliott Sound Products: Low Power FM Transmitter
• Ramsey Electronics: FCC Information