Solution:

Resistive loss:

• Resistive losses within the coax cable arise from the resistance of the conductors and the current flowing in the conductor results in heat being dissipated.

• The actual area through which the current flows in the conductor is limited by the skin effect, which becomes progressively more apparent as the frequency rises.

• To help overcome this multi-stranded conductors are often used.

• To reduce the level of loss due to the coax cable, the conductive area must be increased and this results in low-loss coax cables being made larger.

• However, it is found that the resistive losses increase as the square root of the frequency.

Dielectric loss:

• The dielectric loss represents another of the major losses arising in most coax cables.

• Again the power is lost as dielectric loss is dissipated as heat.

• It is found that the dielectric loss is independent of the size of the RF cable, but it does increase linearly with frequency.

• This means that resistive losses normally dominate at lower frequencies.

• However as resistive losses increase as the square root of frequency, and dielectric losses increase linearly, the dielectric losses dominate at higher frequencies.