Understanding Coaxial Cable Attenuation

Cell Phone Repeater
Cell Phone Repeater
Coaxial Cable Attenuation
Coaxial Cable Attenuation

Coaxial cables are commonly used to carry electrical signals in various electronic devices. Cell phone booster, a popular signal booting device has its three primary components, external antenna, amplifier and indoor antenna connected using coaxial cables.

The signals that reach the receiving end by traveling through a coaxial cable will not have strengths that they had at the transmitting end. In this article, we are discussing in detail about attenuation in coaxial cables.

What Is Coaxial Cable Attenuation?

The power loss of signals caused due to the features of the coaxial cable material is referred to as attenuation. Attenuation increases with an increase in cable lengths. Signal loss is also found to be dependent on frequency, with attenuation tending to increase with frequency although not in a linear fashion.

What Are The Major Constituents Of Coaxial Cable Loss?

Here are the major constituents of coaxial cable loss.

  • Resistive loss: Resistive losses in coaxial cables are rooted in the resistance of the conductors. The actual area through which signals flow is limited by the skin effect which becomes evident as the frequency increases. The issue can be overcome using multi-stranded conductors.
  • Dielectric loss: In the event of dielectric loss, the power manifests itself in the form of heat. Dielectric loss does not depend on the size of the RF cable.
  • Radiated loss: It occurs when radiations emanate out of the cable due to imperfections in the shield. The loss is mostly lesser than resistive and dielectric losses.

How Does Coaxial Cable Attenuation Increase With Time?

Attenuation tends to increase with time due to the following reasons.

  • Flexing: Coaxial cables are designed to be flexible but the attenuation levels increase if the RF cable is bent sharply.
  • Braid contamination: Even if there is no bend in the cable, its performance will gradually decrease over time. This could be due to the contamination of the braid by plasticizers in the outer sheath.
  • Moisture: Moisture penetration will lead to the absorption of power. The extent of absorption depends on versions of polyethene used in the cables. Despite having low attenuation levels, foam polyethene is known to absorb moisture more than solid types.
  • Degradation of braid: Coax cables that use silver plated braids have lower attenuation than cables that use copper braids and tinned copper braids.

To ensure the effective working of your signal boosters, give enough importance to the selection of coaxial cables.