What is a demodulator?
Demodulator is commonly known as a radio tuner. It takes AM, FM and QAM signals and decodes them to sound/video output. Demodulators are used from the first wireless broadcasts and are still used today with Internet modem technology. While modern demodulators are more complex, the act of demodulation has changed very little over the years.
The demodulator is a circuit that separates the amplitude modulation (AM), frequency modulation (FM) and quadrature amplitude modulation (QAM) signals from countless radio waves in our atmosphere and decodes information from the carrier. The carrier is a signal sent from a source such as a radio station or in the case of Walkie interviews or CB radio, another radio. The demodulator was first used before the radio stations were back, when the Morse code was the main form of wireless communication. At that time it was called a detector. This primitive device did not have to convert the signals that are to sound signals, but only had to notice the presence or absence ofDii waves.
The first type of audio signal to work with the demodulator was AM. The envelope detector and product detector are two types of demodulators that help pick up the nose signal from the AM source. The envelope detector went through only one direction and its simplicity was documented by early crystal radio sets. The product detector multiplies an incoming signal with an oscillator signal. The resulting sound is often filled with static and unclear.
Compared to the basic AM settings, FM is much more complicated. FM demodulators come in many different types, but the Foster-Seeley resolution is the most popular. This type of electronic filter regulates its input frequency with output frequency. The result is a much brighter sound than with AM and easier to capture the signal. This is a radio station on the car radio that could come and out of the melody when the car passes through the telEfon poles and goes under the tunnels and why FM stations don't.
Modern demodulators deal with QAM signals that pass through computer modems. This demodulator captures the carriers in the air and converts them to a digital binary code. In this way, computers are able to pick up wireless internet signals. Modern demodulators also help to receive UHF and VHF signals for television antennas.
Demodulators are the cornerstone of wireless technology. Their complexity differs from basic electronic simplicity to high technical complexity. This technology has helped the world to communicate from the Morse to FM radio and wireless Internet.