What is a coaxial cable?
It is a type if cable that has inner conductor surrounded by a dielectric material as an insulation layer, surrounded by a shield conductor, surrounded with the final dielectric material called “Jacket” which protects the inner and the shield conductors.
Why coaxial cable used?
Coaxial cable has the ability to transmit the electromagnetic waves inside it easily as the look of cable assembly makes the waves to be transmitted inside the dielectric which lies between the cable’s conductors. This allows this cable to be installed next to metal objects without having power loss and protect signals from being affected by external electromagnetic interference.
Types of coaxial cables:
Coaxial cable types defined upon the following physical parameters:
- Length of the cable.
- Outside diameter of inner conductor.
- Inside diameter of the shield.
- Dielectric constant of the insulator.
- Magnetic permeability of the insulator.
These parameters define the cable matching resistance, attenuation constant per unit length, and the type of application this cable can be used for in terms of application’s frequency and transmitted power.
Moreover one of the important parameters in these cable is the shield conductor which specifies the ability of the cable to immune external interference and noise regarding the transmitted signal inside it.
Notice as the shielding density increases, there’s a correlated increase in the shield effectiveness value.
Signal leakage is the passage of electromagnetic fields through the shield of a cable and occurs in both directions:
Ingress is the passage of an outside signal into the cable and can result in noise and disruption of the desired signal.
Egress is the passage of signal intended to remain within the cable into the outside world and can result in a weaker signal at the end of the cable and radio frequency interference to nearby devices.