Advantages of Coaxial Cable | disadvantages of Coaxial Cable
This page covers advantages and disadvantages of Coaxial Cable. It mentions Coaxial Cable advantages or benefits and Coaxial Cable disadvantages or drawbacks. It provides links on various topics on Coaxial Cable.
What is Coaxial Cable?
It is most common transmission line used to transmit electrical energy from one location to the another. For example it is used to connect transmitter to an antenna. The signal propagation is in the form of TEM (Transverse Electromagnetic) mode.
Coaxial cable is typically classified based on its impedance viz. 50 Ohm (RG-8 type) or 75 Ohm. The 50 Ohm is used for two way communication, RF & Microwave transmissions, data transmission and M&C applications. The 75 Ohm is used as video cable.
As shown in the figure-1, Coaxial cable consists of two condustors which are separated by
dielectric material. The center conductor (A) and outer conductor (B) (e.g. shield) are
configured to form concentric cylinders with common axis and hence the name.
The center conductor is constucted using solid or seven strand conductors.
The materials commonly used include copper, silver plated copper,
copper clad aluminium, copper clad steel etc. The outer conductor uses multiple
small aluminium or copper conductors. Dielectric layer (C1, C2) separates these two conductors.
It is made using materials such as polyethylene, polypropylene,
fluorinated ethylene propylene etc. Many coaxial cables use
an additional insulating outer sheath or jacket (C2) as shown.
Refer types of coaxial cables>> and Coaxial Line basics and types>>.
Benefits or advantages of Coaxial Cable
Following are the benefits or advantages of Coaxial Cable:
➨Due to skin effect, coaxial cable is used in high frequency applications (> 50 MHz) using copper clad materials for center conductor. Skin effect is result of high frequency signals propagating along outer surface of the conductor. It increases tensile strength of the cable and reduces weight.
➨The cost of coaxial cable is less.
➨The outer conductor in coaxial cable is used to improve attenuation and shield effectiveness. This can be further enhanced with the use of second foil or braid known as jacket (C2 as designated in the figure-1). The jacket is used as protective cover from the environment and makes overall coaxial cable as flame retardant.
➨It is less susceptible to noise or interference (EMI or RFI) compare to twisted pair cable.
➨It supports high bandwidth signal transmission compare to twisted pair.
➨It is easy to wire and easy to expand due to flexibility.
➨It allows high transfer rates with coaxial cable having better shielding materials.
Drawbacks or disadvantages of Coaxial Cable
Following are the disadvantages of Coaxial Cable:
➨It is bulky.
➨It is expensive to install for longer distances due to its thickness and stiffness.
➨As single cable is used for signal transmission across the entire network, in case of failure in one cable the entire network will be down.
➨The security is a great concern as it is easy to tap the coaxial cable by breaking it and inserting T-joint (of BNC type) in between.
➨It must be grounded to prevent interference.