AS9120B, ISO 9001:2015, and FAA AC 0056B ACCREDITED

What Is the Difference Between a Modulator and Demodulator?

There exists two important processes that are utilized in data communication: modulation and demodulation. They make it possible to communicate effectively through the process of transferring data and information with little distortion and loss, as well as through the efficient use of the modulation spectrum. The electronic device created to perform these processes is called a modem which modulates and demodulates information during transmission.

It is important to establish the differences between modulation and demodulation. To start, modulation is the process of superimposing a message signal on a carrier signal to help the message travel over long distances. The carrier signal is composed of high frequency data, and it is used to carry the message signal. A part of a modem, modulation occurs at the transmitting end of the communication system using a modulator circuit. During this process, a particular parameter, be it amplitude, frequency, or phase of the carrier signal, is changed according to the modulating signal or message signal. After modulation, the message is transmitted through the communication channel using a transmitter. On the other hand, demodulation refers to the process of obtaining the original message from the modulated signal which involves the process of separating a message signal from a carrier signal. The demodulation process is performed at the receiver end of a communication system.

Though both modulation and demodulation processes are involved in data communication, they have several differences. To start, modulation involves superimposing a low energy signal on a high energy carrier signal. On the other hand, demodulation involves extracting the message signal from a modulated signal. Modulation is performed at the transmission end of the system, whereas demodulation occurs at the receiving end of the communication system. Modulators are also the electronic circuit required in the modulation process, while the demodulator is the circuit needed to carry out the process of demodulation. During modulation, the message signal is placed on the carrier wave to be transmitted, while in demodulation, the message is separated from the carrier signal.

An additional difference between the two processes is that modulation mixes two different signals together, while demodulation is required for recovering the initial signal before they are combined. The primary purpose of modulation is to assist in the transmission of messages over large distances, while the more complex process of demodulation works to regain the original message over at the receiver end. Finally, in modulation, the signal parameter transforms from a low to high value, whereas demodulation transforms the signal parameter from a high to low value. It is important to note that the most significant difference between the two processes is that the message signal is mixed with the carrier signal during modulation, while in demodulation, the message signal becomes separated from the carrier signal.

Those in the market for high quality modulators, demodulators, and other similar parts should look no further than After Market Aviation Spares. Owned and operated by ASAP Semiconductor, we have more than 2 billion new, used, obsolete, and hard-to-find parts available for your immediate purchase. Many of the parts we offer are subject to rigorous quality control measures to ensure proper functioning and safety. As an AS9120B, ISO 9001:2015, and FAA AC 00-56B accredited parts distributor, you can trust the caliber of our offerings. Once you place an order with us, we work diligently to get your parts delivered to you as quickly as possible. Take your time to fill out one of our online RFQ forms with as much information about your needs as possible. One of our dedicated account managers will get you a quote within 15 minutes of your submission.


Semiconductor's Certifications and Memberships
The only independent
distributor with a
  • All Orders are fulfilled in the U.S.A.
  • All shipments must comply with U.S.A export laws.
  • No exceptions.

“We Proudly Support Intrepid Fallen Heroes Fund that serves United States Military Personal experiencing the Invisible Wounds of War : Traumatic Brain Injury (TBI) and Post Traumatic Stress (PTS). Please visit website ( and help in their valiant effort”.

Thank You for Visiting.

We Hope that You Will Visit Us Again the Next Time You Need NSN Parts and Make Us Your Strategic Purchasing Partner.

Request for Quote

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.