What IS A Radio Receiver

How does a radio receiver communicate over long distances? This is a description of the basic mechanism used. The principle of the receiver is the same, no matter how you communicate; Radio wave, sound wave and optical communication...... It is used when the signal received by the receiver is very weak or requires very high reliability.

Radio Receiver Introduction

In radio terms, a receiver is an electronic device that receives and demodulates radio signals from an antenna, mainly for sound, image positioning information, etc. Radio, television, satellite TV receivers, pagers, GPS, etc. used in People's Daily life are all radio receivers.

Generally speaking, a receiver refers to an electronic circuit composed of a tuning device, a preamplifier and a power amplifier placed in a box. Some older receivers have speakers. This is a common device in hi-fi or home theater systems, but some music 

enthusiasts believe that a separate tuner can provide higher quality performance and sound. The receiver is often the heart of a sophisticated home theater system, providing a selection of sound inputs to a range of playback devices, such as record players, CD players,

 and cassette players. Video equipment such as video cassette recorders, DVD players, video game consoles, and television sets.

Let's say I have a little device that beeps. It's just a small box with a speaker and an on/off switch. When the switch is turned on, the device makes a continuous beep. When you turn off the switch, the device will be silent. This device is a transmitter.

Second, let's say I have another little device that can hear beeps. It's also a small box with a microphone and a lamp. When the microphone hears the beep, the light goes on. When the microphone doesn't hear the beep, the light stays dark. This device is a receiver.

You can use these two small devices as you wish:

When you turn on the transmitter switch, the receiver's light starts to glow. When you turn off the transmitter's switch, the receiver's light dims. Let's wait.

If the receiver has been established in a basic way, then the distance at which the communication works will be a few meters or tens of meters:

If you put the receiver 50 meters away from the transmitter, then there is no more communication. When you turn on the transmitter's switch, the receiver's light does not start to glow. It will remain dark.

However, if you build a long distance receiver, then the distance can be more than 50 meters:

Suppose you are in a noisy city. You put the transmitter somewhere and walk away. At a distance of tens of meters, your ears can no longer hear the sound of the transmitter. However, the transmitter can still be heard by the remote receiver after walking away for 1 km. 

Amazingly, communication works: when the transmitter's switch is pushed to open; The receiver's light began to glow. And when the transmitter's switch is pulled to off, the receiver's light dims. Distance 1 km! It was magic.

There's only one downside: communications are pretty slow now. When the transmitter's switch is pulled to turn on, you have to wait 1 minute until the receiver's light starts to glow. And when you push the transmitter's switch to off, you have to wait 1 minute again until the receiver's light dims.

Thanks to this technology, it is possible to communicate with space probes outside the solar system.

So our aim now is to explain how this little miracle works.