How Does An FM Transmitter Work?

An FM transmitter works on electromagnetism, as it is a low-power transmitter that sends on a selected FM frequency. It converts digital data into analog data and vice versa.

You may not know this, but the same technology that FM transmitters work with is very vital to speeds and mobile tech. It can help boost signals, whether it's audio or not, of the device connected to it because it works as a converter.

Inside the FM Transmitter

As mentioned above, it converts signals – firstly, the audio output is converted to analog, then converted to FM signals. The transmitters are connected to a device via or, in older versions, a headphone jack.

The signals it receives from the connected device are then broadcast over a frequency band, picked up when the car radio (or any radio) is tuned in.

An oscillator inside the transmitter generates the signal at a certain frequency using a voltage modulator to make this happen. If the modulator is not present, the frequency is broadcast on a predefined frequency band. However, the signal is sent out through an antenna into space, where it can be picked up by radios.

Before a signal is sent out, the airwave is called a sine wave, and it has no data encrypted into it. The data is encrypted onto sine waves when electromagnetic energy is used. Therefore, sound waves are converted into sine waves, which can be sent, received, and reconverted into audio.

Moreover, an electromagnetic field is produced when signals push through the broadcasting antenna, releasing electromagnetic waves. When one antenna is tuned into the emitted frequency, it undoubtedly catches enough radio signals to play the sound.

When you hear static, the signals are not being received at a great enough frequency, and there is some interference with the signal.

What An FM Transmitter Does

People often use FM transmitters to play music in their cars without USB or AUX wires. Modern Bluetooth transmitters have become much easier to avoid using any cables. It also allows for hands-free calling, music without any distractions, and an overall safe yet enjoyable experience.

So, FM transmitters use the connected device as an audio source, which, as explained above, the digital signals turn into analog and are then broadcasted into space. However, there are many more ways people can use an FM transmitter.

For example, bigger, stronger FM transmitters can broadcast a pirate radio station, enhance signals for your , radio, etc. Often, low-power FM transmitters are used for personal use. In the case of a larger radio station, they have much larger FM transmitters that require more power to send out bigger radio waves.

An FM transmitter can work only up to a certain range. It varies from one transmitter to the next; however, a common low-power transmitter will operate on 87.5 MHz to 108.0 MHz (around the globe). Whereas in Japan, it is 76.0 MHz to 95.0 MHz, in Russia, it is between 87.5 and 108 MHz, and the US and Canada have a range of 88.1 MHz and 107.9 MHz.

Table of Contents