What is Coaxial Cable ?

Coaxial cable is typically used by cable operators, telephone companies, and internet providers to transmit data, video, and voice communications to customers. Its installation and implementation are easy but it is less efficient than optical fiber also it provides moderately high bandwidth in comparison to optical fiber. 

What is Coaxial Cabe?

Coaxial Cable is a type of guided media made of Plastics, and copper wires which transmit the signal in electrical form rather than light form. Coaxial cable is also known as coax. The core copper conductor is used for the transmission of signals and the insulator is used to provide insulation to the copper conductor the insulator is surrounded by a braided metal conductor which helps to prevent the interference of electrical signals and prevent cross talk. This entire setup is again covered with a protective plastic layer to provide extra safety to the cable.

Structure of Coaxial Cable

• Copper conductor: A central conductor, which consists of copper. The conductor is the point at which data is transmitted.
• Insulator: Dielectric plastic insulation around the copper conductor. it is used to maintain the spacing between the center conductor and shield.
• Braided mesh: A braided mesh of copper helps to shield from electromagnetic interference, The braid provides a barrier against EMI moving into and out of the coaxial cable.
• Protective plastic layer: An external polymer layer, which has a plastic coating. It is used to protect internal layers from damage.

Coaxial cable

How does Coaxial Cables Work?

Coaxial cables consist of concentric layers of electrical conductors and insulating material. This structure ensures that signals are protected within the cable and that electrical interference does not interfere with the signal. The primary conductor layer consists of a thin conducting wire made of solid or braided copper. A dielectric layer comprised of an insulating substance with well-defined electrical properties surrounds the wire. The dielectric layer is then surrounded by a shield layer of metal foil or braided copper. The whole thing is wrapped in an insulating covering. The outside metal shield layer of a coaxial cable is normally connected in the connectors at both ends to filter the signals and reduce all unwanted transmission, so this is how coaxial cable works.

Types of Coaxial cables

• Hardline coaxial cable: Hardline coaxial cable’s center conductor is made of copper, silver and has a larger diameter when compared to other coaxial cables.
• Flexible coaxial cable: The flexible coaxial cables are very flexible and the inner conductor is surrounded by a flexible polymer.
• Semi-rigid coaxial cable: Semi-rigid coaxial cable uses a solid copper outer sheath with a dielectric of Polytetrafluoroethylene.
• Formable coaxial cable: It is an alternative to semi-rigid cable, instead of a rigid copper outer sheath a flexible metal sheath is utilized.
• Twinaxial cable: It has two central conductors in the core and a single outer core and dielectric. these cables are best for low-frequency digital and video transmission.
• Triaxial cable: It is also known as Triax. It is very much similar to a coaxial cable but with an additional copper braid added to it, the braid works as a shield and protects from noise. Triaxial cables offer more bandwidth.
• Rigid coaxial cable: Rigid coaxial cable is made up of two copper tubes supported at cable ends and fixed intervals across the length of the cable using PTFE supports or disk insulators. The rigid coaxial cable cannot be bent. It is mainly used in TV and FM broadcasting systems.

Types of connectors

• Bayonet Neill-Concelman (BNC): This connector is used with television, video signals, and radios that operate at frequencies less than 4 GHz.
• Threaded Neill-Concelman (TNC): This connector is a twisted variation of the BNC connector that is found in telephones. TNC connectors can function at up to 12 GHz.
• SubMiniature version A (SMA): This connector is compatible with mobile phones, Wi-Fi antenna systems, microwave systems, and radios. SMA connectors can function at up to 18 GHz.
• SubMiniature version B (SMB): This connector is compatible with telecommunications hardware.
• QMA. QMA connectors are a type of SMA connector that opens quickly and is commonly used in industrial and communications electronics.
• Radio Corporation of America (RCA): These connections are used for audio and video. These are the yellow, white, and red cables commonly used with vintage televisions. RCA connectors are also known as A/V jacks
• F connectors: Also known as F-type connectors, these are seen in digital and cable televisions. These commonly use RG-6 or RG-59 cables.

Uses of Coaxial Cable

• Television: Coaxial cable used for television would be 75 Ohm and RG-6 coaxial cable.
• Internet: Coaxial cables are also used for carrying internet signals, RG-6 cables are used for this.
• CCTV: The coaxial cables are also used in CCTV systems and both RG-59 AND RG-6 cables can be used.
• Video: The coaxial cables are also used in video Transmission the RG-6 is used for better digital signals and RG-59 for lossless transmission of video signals.
• HDTV: The HDTV uses RG-11 as it provides more space for signals to transfer.

Advantages of Coaxial Cable

• Coaxial cables support high bandwidth.
• It is easy to install coaxial cables.
• Coaxial cables have better cut-through resistance so they are more reliable and durable.
• Less affected by noise or cross-talk or electromagnetic inference.
• Coaxial cables support multiple channels

Disadvantages of Coaxial Cable

• Coaxial cables are expensive.
• The coaxial cable must be grounded in order to prevent any crosstalk.
• As a Coaxial cable has multiple layers it is very bulky.
• There is a chance of breaking the coaxial cable and attaching a “t-joint” by hackers, this compromises the security of the data.

Difference between RG-59 and RG-6

RG-59	RG-6
RG-59 have lesser bandwidth capabilities.	RG-6 have more bandwidth capabilities.
RG-59 is suitable for lower frequency.	RG-6 is suitable for larger frequency.
They are cheap.	RG-6 are costly as compare to RG-6.
Less shielding (typically braided copper wire).	More shielding (typically quad shielded with additional layers).

Interference issues with Coaxial Cable

Coaxial cables faces a range of types of interference. One of the issue is Signal leakage, it happens when an electromagnetic field goes through the cable’s outer shielding. In other conditions, an outside signal may leak through the insulator. Straight-line feeds to commercial radio broadcast towers have the lowest leakage and interference because their shields are smooth and conductive, with minimal gaps.

Difference Between Coaxial Cable and Optical Fiber

Coaxial Cable	Optical Fibre
Coaxial Cable is used to transmit the signal/data is in electrical form.	Optical Fiber is used to transmit the signal/data is in light form.
The diameter of Coaxial cable’s is larger as compare to optical fiber.	The diameter of Optical fiber is small.
The cost of coaxial cable is less.	The cost of optical fiber is high.
Coaxial cable is heavier than optical fiber in weight	Optical cable is lighter in weights.

For more details just check the published article Difference Between Coaxial Cable and Optical Fiber.

Frequently Asked Question on Coaxial Cable – FAQs

How do you terminate coaxial cable?

Coaxial cable termination involves removing the outer insulation and shielding, exposing the center conductor, and connecting it to a connector (such as an F-type or BNC connection) via compression or crimping tools.

What factors affect the performance of coaxial cable?

Several factors can affect the performance of coaxial cable, including cable length, signal frequency, impedance matching, connection and termination quality, environmental conditions (such as temperature and moisture), and electromagnetic interference (EMI).

Why is it called coaxial cable?

The term “coaxial cable” refers to a physical channel that carries the signal and is surrounded by another concentric physical channel that operates along the same axis.