Difference Between FM Modulator and FM Transmitter (With Table)

FM radio can be cited as one of the earliest forms of mass communication. Radio opened the doors for quick and wireless communication, which was a huge leap from the earlier wired methods of communication. FM Modulator and FM Transmitter are both important components that are necessary for the desired functioning of the radio.

FM Modulator vs FM transmitter

The main difference between FM modulator and FM transmitter is that FM modulator modulates or modifies the FM signal that is being transmitted by the radio so that it can be correctly sent through the FM carrier wave, whereas FM transmitter is responsible for transmitting or sending the actual wave.

FM Modulator is a device that combines the FM signal wave that is being transmitted from the radio, with the FM carrier wave. Radio signals are transmitted by overlaying the signal onto the carrier wave. Carrier wave then transmits this signal to other radio devices or stations. This is done by the modulator.

FM Transmitter is the component that is responsible for transmitting or sending the actual radio signal. For broadcasting radio waves, generally, the FM carrier wave frequency is in the range of 87.5 to 108.0MHz. Thus the transmitter generates a radio signal that can be modulated on the carrier wave and can be broadcasted.

Comparison Table Between FM Modulator and FM Transmitter

Parameters of ComparisonFM ModulatorFM Transmitter
DefinitionFM Modulator modulates the radio wave to be carried by the carrier waveFM Transmitter generates the radio signal
OperationModulation is done by selecting the frequency of the radio station where the signals are to be transmittedTransmission is done by generating waves in the frequency range of the carrier wave
Signal TypeModulation is done on AC waves in the range 88 to 108MHzThe sound waves or digital signal is converted into AC analog waves
Factors AffectingIs affected by the static noise in the wavesIs affected by environmental conditions, antenna height, static noise, etc
UsesUsed on most radios, mobile phones, and other transmission devicesUsed in conjunction with a receiver to receive the signals

What is FM Modulator?

FM Modulator is a device that is used to modulate or modify the radio signal so that it can be carried by the carrier wave. FM modulator is an important component of any radio transmission device and is necessary for the function of a radio device.

FM radios transmit signals in the range of 88 to 108MHz frequency. The waves are transmitted through a carrier wave. A carrier wave or carrier signal is a wave that is set at a particular frequency.

This wave carries other waves and radio signals so that they can be transmitted between different radio stations and channels. Hence for any radio wave to be transmitted from one device to another, the wave has to be encoded onto the carrier wave.

The modulator circuit converts the radio wave into a suitable frequency wave that can be encoded onto the carrier wave. To achieve this, the FM Modulator combines the radio wave and the carrier wave, with the help of some modulation logic built into the device.

This resulting wave has a frequency that is in the range of the carrier wave frequency and thus the wave can be encoded onto the carrier wave transmitted through the carrier wave.

What is FM Transmitter?

In signal transmission devices such as radios, FM Transmitter is the component that is responsible for the actual transmission of the signals.

The signal is initially in the form of electronic data, sound signals, or digital data. This data is converted into an analog AC signal, which is a sinusoidal wave signal.

As radio waves are in the form of sin waves, this wave can then be transmitted. Before transmission, the frequency of the wave has to be modulated so that it can be encoded onto the Carrier wave. This is done by the FM modulator.

After modulation, the wave is transmitted or broadcasted by the transmitter circuit. The strength of transmission depends upon the power of the transmitter circuit. Circuits with higher transmission capabilities can transmit signals at a higher range.

The signals are transmitted in the frequency range of 88 to 108MHz, but the range of transmission depends on the capabilities of the circuit.

Apart from this, signal transmission is sometimes affected by environmental factors as well. Environmental conditions, static presence in the carrier wave, antenna height are some of the factors that affect the range as well as strength of the signal.

A powerful signal transmitter should be used for successful transmission under such conditions.

Main Differences Between FM Modulator and FM Transmitter

  1. FM Modulator is used to modulate the FM signal for transmission through FM carrier wave. FM transmitter is the device that actually transmits the signal.
  2. Modulation is done by selecting the suitable frequency from the carrier wave frequency range. Transmission is done after selecting the appropriate carrier wave frequency.
  3. Signals are modulated in the range of 88 to 108MHz. Signals are converted into AC waves and then transmitted.
  4. Static noise in the carrier wave is the factor that affects modulation the most. Transmission is affected by factors such as environmental conditions, static noise, antenna height etc.
  5. FM modulators are mostly used in personal radio devices, mobile-phone to modulate the waveform. Transmitters are used in signal broadcasting devices, in conjunction with a receiver circuit.


In telecommunication, signal transmission depends upon the modulation and transmission-reception circuits. The signal has to be properly modulated before transmission.

Modulation is done with the help of a modulation circuit. Modulation basically converts the radio signal into a wave that can be transmitted through the Carrier wave.

Without modulation, the wave transmission on the carrier wave is not possible.

After modulating the wave, the signal is transmitted by the transmission circuit. The strength and range of transmission depend on the power of the transmission circuit.

A powerful transmission circuit can broadcast signals with a longer range. Transmission circuits are used in conjunction with a reception circuit, for receiving the signals.


  1. https://ieeexplore.ieee.org/abstract/document/780016/
  2. https://www.diva-portal.org/smash/record.jsf?pid=diva2:437259
  3. https://ieeexplore.ieee.org/abstract/document/1403621/
  4. https://ieeexplore.ieee.org/abstract/document/5940712/
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