Final answer:
Signal attenuation through coaxial cable is typically greater at higher frequencies (such as forward path frequencies) than at lower sub-band frequencies, due to increased energy loss as heat and dielectric losses.
Step-by-step explanation:
The question asks about the signal attenuation through coaxial cable in the sub-band frequency spectrum compared to the attenuation at forward path frequencies. Signal attenuation refers to the weakening of a signal as it travels through a transmission medium. In the case of coaxial cables, attenuation is influenced by several factors, including the length of the cable, the materials used in the inner and outer conductors, the resistivity of the insulating material, and the frequency of the signal being transmitted.
The sub-band frequencies are typically lower in frequency compared to forward path frequencies, which are used for the transmission of the main signal. Generally, higher frequency signals experience more attenuation due to the increased energy loss as heat in the form of resistive heating within the conductors and dielectric losses within the insulator. Therefore, signal attenuation is often greater at forward path frequencies than at sub-band frequencies. Provided the cable is well-shielded, the effect of electronic noise on the cable acting as an antenna is minimized.
Understanding this principle is significant in the design and application of coaxial cable systems, whether it be for television, internet, or radio communication. The resistance of coaxial cable plays an integral role in determining how much signal is lost due to attenuation, affecting the overall performance and efficiency of a transmission system.