What is optical fiber, coaxial cable

Optical fiber, referred to as optical fiber, is a kind of glass fiber that can conduct light with high quality. If you wrap many technically treated fibers together, you get what we often call fiber optic cables.

Optical fibers have a very strong ability to conduct light, and they can transmit a large amount of information at the same time by using optical cable communication. For example, a single optical cable channel can hold one billion people talking at the same time, and multiple TV programs can be transmitted at the same time. The optical fiber has good anti-interference performance, no electrical radiation, high communication quality, and can prevent eavesdropping.

The quality of the optical cable is small and thin, not afraid of corrosion, and it is also very convenient to lay, so it is a very good communication material. At present, many countries have used fiber optic cables as long-distance communication trunks. China has also begun to produce optical fibers, which have been put into use in some regions and cities.

With the progress of the times and the development of science, optical fiber communication is bound to become popular.

In addition to communication, optical fiber is also used in many aspects such as medical treatment, information processing, energy and image transmission, telemetry and remote control, lighting, etc. For example, an optical fiberscope can be introduced into the heart to measure blood pressure, temperature, etc. in the heart. In terms of energy and information transmission, optical fibers are also widely used.

A coaxial cable is a cable that has two concentric conductors, and the conductor and shield share the same axis. The most common coaxial cable consists of a copper wire conductor isolated by an insulating material, another ring conductor and its insulator on the outside of the inner insulation, and then the entire cable is encased by a sheath of PVC or Teflon material.

At present, there are two types of coaxial cables commonly used: 50 and 75 coaxial cables.

75 coaxial cable is often used in CATV network, so it is called CATV cable, the transmission bandwidth can reach 1GHz, and the transmission bandwidth of the commonly used CATV cable is 750MHz.

50 coaxial cable is mainly used for baseband signal transmission, the transmission bandwidth is 1 2omhz, bus type Ethernet is the use of 50 coaxial cable, in Ethernet, the maximum transmission distance of 50 thin coaxial cable is 185 meters, thick coaxial cable up to 1000 meters.

It's like what the dude said above.

Optical fiber is now a popular material for laying backbone networks.

Coaxial cable is now mainly used for the transmission of cable television.

1.What are the advantages and disadvantages of coaxial cable and optical fiber ratio, and why is radio and television still in use? The reason for the slow transformation of radio and television.

2.The early TVs were analog TVs, which used coaxial cables to enter the home, called CATV, and the early TVs were popularized quickly, so every household had cable TV. The coaxial cable is convenient to enter the home, the installation is simple, and the bandwidth of the coaxial cable is not small, which can reach gigabit.

3.Optical fiber access technology was first used in telecommunication networks, with many advantages of optical fiber, large bandwidth, high rate, anti-interference, confidentiality, lightweight and anti-corrosion. With rapid development, long-distance interconnection is now all optical fiber communication.

4.It is precisely because of the advantages of optical fiber that IPTV network digital TV is rapidly popularizing, and the traditional CATV is gradually withdrawn, and soon the cable TV coaxial cable will be eliminated.

1. Twisted pair.

Referred to as TP, more than one pair of twisted pairs are encapsulated in an insulating jacket, in order to reduce the degree of signal interference, each pair of twisted pairs in the cable is generally formed by two insulated copper wires twisted with each other, so it is called twisted pair. Twisted pairs are divided into unshielded twisted pair (UTP) and shielded twisted pair (STP).

2. Coaxial cable.

Consists of two conductors wound around the same axis. It has the characteristics of strong anti-interference ability, simple connection, etc., and the information transmission speed can reach hundreds of megabits per second, which is the preferred transmission medium for medium and high-end LANs.

3. Optical fiber. Also known as optical cable or optical fiber, it is composed of an optical fiber core, a glass mesh layer and a shell that can absorb light. It is a small and flexible transmission medium composed of a group of Senhu optical fibers used to propagate light beams.

The optical principle is applied, the light beam is generated by the optical transmitter, the electrical signal is turned into an optical signal, and then the optical signal is introduced into the optical fiber, and the optical signal is received by the optical receiver at the other end, and it is turned into an electrical signal, which is decoded and then processed.

4. Radio waves.

Radio waves refer to electromagnetic waves in the radio frequency band that propagate in free space, including air and vacuum. Radio technology is the technology that transmits sound or other signals through radio waves. The principle of radio technology is that a change in the intensity of the current in a conductor produces radio waves.

Using this phenomenon, information can be loaded on top of radio waves by modulation.

5. Microwave. Microwave refers to electromagnetic waves with a frequency of 300MHz-300GHz, which is the abbreviation of a finite frequency band in radio waves, that is, electromagnetic trapped slow waves with a wavelength of 1 meter (excluding 1 meter) to 1 millimeter, which is a general term for decimeter waves, centimeter waves, millimeter waves and submillimeter waves. The frequency of microwaves is higher than that of ordinary radio waves, and it is also commonly referred to as "ultra-high frequency electromagnetic waves".

Summary: What is a coaxial cable? Coaxial cable is a type of wire and signal transmission line, which can be used for the transmission of analog and digital signals, suitable for a wide variety of applications, the most important of which are television transmission, long-distance transmission, short-distance connections between computer systems, and local area networks.

So, what is the difference between coaxial and non-coaxial cables? Let's take a look. 1. What is coaxial cable?

What does coaxial cable mean.

Coaxial cable is a kind of wire and signal transmission line, which is generally caused by four layers of materials: the innermost is a conductive copper wire, the outside of the line is surrounded by a layer of plastic (for insulator and dielectric), and there is a thin layer of mesh conductive material (generally copper or alloy) outside the insulator, and then the outer layer of the conductive material is the outermost layer of insulating material as the outer skin.

What signals are transmitted by coaxial cables.

Coaxial chain cable can transmit digital signals, can also transmit analog signals, the specific signal depends on the way used by the cable station to transmit, the impedance is generally 75 ohms. For example, the traditional CCTV coaxial cable transmits radio frequency signals, as well as our common audio and ** cables also belong to the category of coaxial cables.

Coaxial cable transmission distance.

Coaxial cable is only suitable for short-distance transmission of image signals, when the transmission distance reaches about 200 meters, the image quality will be significantly reduced, especially the color.

Classification of coaxial cables.

1. According to the use.

Baseband coaxial cable: The shielded wire of the commonly used baseband cable is made of copper and has a characteristic impedance of 50 (such as RG-8, RG-58, etc.).

Broadband coaxial cable: The shielding layer of the cable commonly used in broadband coaxial cable is usually stamped with aluminum, and the characteristic impedance is 75 (such as RG-59, etc.).

2. According to the size of the diameter.

Thick coaxial cable: suitable for relatively large local networks, it has long standard distance and high reliability. Since there is no need to cut the cable during installation, the location of the computer can be flexibly adjusted according to your needs.

However, the thick cable network must be installed with transceiver and transceiver cables, which is difficult to install, so the overall cost is high.

Fine coaxial cable: the installation is relatively simple, the cost is low, but because the installation process to cut off the cable, the two ends must be installed with the basic network connector (BNC), and then connected to both ends of the T-type connector, so when there are many joints, it is easy to produce the hidden danger of poor contact, which is one of the most common faults in the current operation of Ethernet.

Second, the difference between coaxial cable and non-coaxial cable.

1. The constituent materials are different.

Coaxial cable: The constituent material is a copper wire conductor isolated by an insulating material.

Non-coaxial cable: The constituent material is several wires or sets of wires.

2. Different classifications.

Coaxial cable: It is divided into baseband coaxial cable and broadband coaxial cable.

Non-coaxial cable: divided into DC cable and AC cable.

3. Different types.

Coaxial cable: It is divided into thin cable RG-58 and thick cable RG-11.

Non-coaxial cable: It is divided into flame-retardant rubber cable, nuclear-grade cable, bare wire and bare conductor products, power cable, communication cable and optical fiber, magnet wire (winding wire), and flexible fireproof cable.