Why coaxial cables are highly insulated?

Coaxial cables are highly insulated to minimize signal loss, interference, and noise. The insulation, commonly made of materials such as polyethylene or Teflon, serves several purposes:

1. Preventing signal leakage: The insulation layer insulates the inner conductor (usually a copper wire) from the outer conductor (a cylindrical metal shield). This prevents the signal from leaking out and interfering with other devices or nearby cables.

2. Shielding against external interference: The outer conductor acts as a shield that protects the inner conductor and the signal it carries from external electromagnetic interference. The insulation layer provides an extra barrier to further shield against these external interferences, such as electromagnetic waves from other electronic devices.

3. Minimizing signal loss: The insulation material has a high dielectric constant, which allows it to efficiently carry the electromagnetic waves through the cable. This reduces signal loss over long distances.

4. Providing impedance matching: Coaxial cables have a specific characteristic impedance, typically 50 or 75 ohms, required for efficient signal transmission. The insulation material helps to maintain this characteristic impedance throughout the length of the cable, ensuring proper signal transfer without reflections.

Overall, the high insulation of coaxial cables helps to maintain the integrity of the signal by minimizing loss, interference, and noise, making them suitable for various applications that require high-quality transmission of signals, such as in television broadcasting, telecommunications, and data communication.