Dielectric (Insulation)

Dielectric materials are insulating materials that are used in cables to provide physical separation between the conductors, which are typically made of metal. These materials are chosen for their ability to reduce the amount of electrical signal loss that occurs as a signal travels through the cable. This is because they have a relatively high resistance to the flow of electric current, which means that they do not allow the electrical charge to flow easily from one conductor to the other.

In cables, the dielectric material is typically a solid, non-conductive substance that is placed between the conductors. It acts as a barrier, preventing the electrical charge from passing through it. This reduces the amount of signal loss that occurs as the signal travels through the cable, which in turn improves the overall signal quality.

The type of dielectric material that is used in a cable can have a significant impact on the cable's performance. Some materials, such as air, have a very low dielectric constant, which means that they do not impede the flow of electric current very much. As a result, cables that use air as the dielectric material tend to have low signal loss and high signal quality. Other materials, such as foam, have a higher dielectric constant, which means that they are more effective at reducing signal loss.

In general, the dielectric material used in a cable is chosen based on a number of factors, including the type of signal being transmitted, the distance the signal needs to travel, and the cable's intended use. By carefully selecting the appropriate dielectric material, it is possible to optimize the performance of a cable and improve the quality of the transmitted signal.

KEY TAKEAWAYS FOR DIELECTRIC CONSTANT
• Electrical property used to determine Capacitance, Velocity of Propagation, Impedance and relative performance of the insulating material.

DIELECTRIC CONSTANT
• Symbol: Er
• Very important for electronic cables.
• Lower Er = Lower capacitance, Higher impedance, Lower attenuation.
• Air is best dielectric (Er = 1).
• Adding air to (foaming) any material lowers its dielectric constant.

DIELECTRIC STRENGTH
• The material’s ability to withstand voltage breakdown.
• Expressed in Volts (V) or Kilovolts (KV).