What is a coaxial cable?

2 years ago | articles

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We are at your service with another article about coaxial cable.
Coaxial cable is a type of copper cable that is constructed with a metal shield and other components designed to prevent signal interference.
A coaxial cable is primarily used by cable television companies to connect their satellite dish facilities to customers' homes and offices. 
Some homes and offices use coaxial cable, but twisted-pair cabling has largely replaced the widespread use of coaxial cable as an Ethernet
 connection medium in enterprises and data centers.

Coaxial cable gets its name because it consists of one physical layer that carries the signal surrounded by another concentric physical 
channel that both travel along the same axis. The innermost layer is usually a copper wire, which is then surrounded by an insulating
 layer between it and the outer layer. The outer layer usually acts as copper mesh. Another layer of insulation surrounds both the inner
 and outer channels. Many of these cables or coaxial pairs can be placed in an outer casing and, with repeaters, can carry information
 over long distances.

Coaxial cables have concentric layers of electrical conductors and insulating materials. This structure ensures that signals
 are contained within the cable and prevents electrical noise from interfering with the signal.

The central conductive layer is a thin conductive wire, solid copper or braided. A dielectric layer made of an insulating 
material with well-defined electrical properties surrounds the wire. A protective layer then surrounds the dielectric layer with
 metal foil or woven copper mesh. The whole assembly is wrapped in an insulating jacket. The outer metal shielding layer of the
 coaxial cable is usually grounded at the joints at both ends to protect the signals and serves as a place for stray interfering 
signals to propagate.

Coaxial cable design depends on the control of cable dimensions and materials. Controlling these factors helps to 
establish a constant value for the characteristic impedance of a coaxial cable.
Types of coaxial cable

There are different types of coaxial cables, some of which are:
Hard-line coaxial cable Hard-line coaxial cable relies on round copper tubes and a combination of shielding metals such as aluminum
 or copper. These cables are usually used to connect the transmitter to the antenna.

Triaxial cable has a third layer of protection, which is connected to the ground to protect the signals sent down the cable.
Rigid-line coaxial cables Rigid coaxial cables consist of twin copper tubes that act as non-bendable tubes. These lines are 
designed for indoor use between high powered radio frequency (RF) transmitters.
Radiating cable The radiating cable mimics many of the components of a rigid cable, but with grooves tuned in the shield to 
match the RF wavelength at which the cable operates. Commonly used in elevators, military equipment and underground tunnels.

Types of connectors
There are several types of coaxial cable connectors, separated by two styles: male and female connectors. Types of connectors include the following:
Bayonet Neill-Concelman (BNC): This connector is used for TV, video and radio signals below 4 GHz.
Threaded Neill-Concelman (TNC): This connector is a version of the BNC connector and is used in cell phones. TNC connectors work up to 12 GHz.

SubMiniature version A (SMA): This connector is used for mobile phones, Wi-Fi antenna systems, microwave and radio systems. SMA connectors work up to 18 GHz.

SubMiniature version B (SMB): This connector can be used with telecommunications hardware.

QMA: QMA connectors are a quick lock type of SMA connectors used with industrial and communications hardware.

Radio Corporation of America (RCA): These connectors are used in audio and video. These are the grouped yellow, 
white and red cables used in older televisions. RCA connectors are also called A/V jacks.

F connectors: They are also called F-type connectors, which are used in digital and cable TVs. These usually use RG-6 or RG-59 cables.

Uses of coaxial cables

In homes and small offices, short coaxial cables are used for cable television, home video equipment, radio equipment, and measuring devices.
 Historically, coaxial cables were also used as an early form of Ethernet, supporting speeds of up to 10 Mbps. Since then, twisted pair cabling 
has largely replaced the use of coaxial cables.

However, coaxial cables are widely used for cable Internet broadband. Coaxial cables are also used in cars, airplanes, military and medical 
equipment, as well as for connecting satellite dishes, radio and television antennas to the respective receivers.

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