The Function Of Coaxial Cable

2023-05-24 119

A coaxial cable consists of two conductors. The center line of the coaxial cable is used to transmit signals. The metal shielding net has two functions: one is to serve as a common ground for the signal, providing a current loop for the signal; the other is the shielding net as a signal to suppress the interference of electromagnetic noise to the signal. There is a layer of semi-foamed polypropylene insulation between the center conductor and the shielding net, which determines the transmission characteristics of the cable and effectively protects the intermediate conductor.


Coaxial cables are widely used for audio, video or radio frequency transmission. The transmission impedance is generally 75_, which has become the standard impedance for video transmission (50_ impedance was also used in early video transmission). Due to its reliable physical characteristics, advanced standard coaxial cables are generally more expensive than twisted pair cables and have excellent audio and video performance. The frequency, resolution and effective transmission distance of the cable play a decisive role in the audio and video system.


In addition, it should be noted that in order to maintain the correct electrical characteristics of the coaxial cable, the cable shielding layer must be grounded, and there should be terminals at both ends to reduce signal reflection.


installation method:


Coaxial cables are generally installed between devices. Each user position is equipped with a connector to provide an interface for the user. The interface is installed as follows:


(1) Fine lines


Cut the cable and connect the BNC end to both ends of the cable, and then to both ends of the T connector.


(2) Thick rope


Thick cables are usually installed using a splint-type TAP device, which uses the guide pin on the TAP to penetrate the insulation layer of the cable and directly connect to the conductor. Place terminations at both ends of the cable to reduce reflected signals.