Coaxial cable

Definition

A coaxial cable is a type of electrical cable consisting of a central conductor, an insulating layer, a metallic shield, and an outer insulating layer. It is used for transmitting high-frequency signals with minimal signal loss.

5 Must Know Facts For Your Next Test

1. Coaxial cables have a characteristic impedance that affects signal transmission and matching.
2. The capacitance per unit length of a coaxial cable depends on the dielectric material between the conductors.
3. Coaxial cables can store energy in their electric field due to their capacitance properties.
4. The magnetic field generated by the current in the central conductor and shield can induce inductance in the coaxial cable.
5. Attenuation in coaxial cables increases with frequency due to skin effect and dielectric losses.

Review Questions

• What factors determine the characteristic impedance of a coaxial cable?
• How does the dielectric material inside a coaxial cable affect its capacitance?
• Explain how both electric and magnetic fields are involved in energy storage in a coaxial cable.

Related terms

Capacitance:

The ability of a system to store charge per unit voltage across its plates.

Inductance:

The property of an electrical conductor that opposes changes in current flow through it by generating an electromotive force.

Skin Effect:

The tendency of alternating current (AC) to distribute itself within a conductor such that the current density near the surface is greater than at its core.