What is a Radio Receiver?

In radio terms, a receiver is an electronic device that receives and demodulates radio signals from an antenna, and is mainly used for sound, image positioning information, and so on. Radios, televisions, satellite television receivers, pagers, GPS, etc. that people use in their daily lives are radio receivers.

A radio receiver is a communication device used to receive radio signals. Because the electromagnetic waves from space are already very weak, and there is a lot of interference and noise, radio receivers must have the ability to amplify signals, select signals, eliminate interference, and demodulate signals. There are roughly three types of radio receivers: direct-type, super-heterodyne, and super-regenerative. Among them, the super-heterodyne receiver has the best receiving performance and the most stable operation. It is widely adopted in the machine.

Radio receiver A device that uses an antenna to receive a radio signal, selects a desired signal from it, and converts it into sound, image, and code. The main components are filters, electric oscillation amplifiers, detectors, speakers, electronic picture tubes, etc. There are many types, such as telegraph receivers, radios, television receivers, etc. ^[2]

Generally speaking, radio receivers often refer to

The basic composition of a radio transmitter includes five parts: a baseband signal processing circuit, a carrier generator, a modulator, a high-frequency power amplifier, and a transmitting antenna. The baseband signal processing circuit includes the Various front-end processing of audio signals, such as audio amplification, audio filtering (limiting the frequency to 300 ~ 3400Hz), and possibly voice compression (amplitude limitation to prevent excessive modulation) and pre-emphasis (for FM transmitters) Middle) etc .; the modulator is used to modulate the processed audio signal onto the high-frequency carrier. Different modulation methods use different modulators. In direct frequency modulation, the modulator and the carrier generator are combined into one; the high-frequency power amplifier. Amplify the high-frequency modulated wave to make the output power of the transmitter meet the requirements. A transmitting antenna is a unit that converts high-frequency electrical signals into electromagnetic waves. For a transmitter, it is a load.

Basic principles of radio transmitters

The figure is only the basic components of a radio transmitter. The actual transmitter must also add some circuits, such as various filters, frequency converters, and some control circuits, etc. according to the requirements of specific functions and technical indicators, and its amplifiers are often multi-stage.