Which frequency band is suitable for short-range communications, as described?

• A. Waveguide
• B. Very High Frequency
• C. Satellite
• D. Microwave

Answer: (B)

The main idea is that short-range communications rely on a frequency band that supports reliable line-of-sight transmission with practical antenna sizes for both aircraft and ground stations. Very High Frequency, spanning roughly 30 to 300 MHz, is ideal for this. VHF signals travel predominantly in straight lines and don’t require complex infrastructure to cover the typical distances around an airport, making voice communication between pilots and air traffic control or ground operations clear and dependable. The antenna sizes at VHF are manageable for both aircraft and towers, which is another reason it’s favored for close-range airfield communications.

Waveguide isn’t a frequency band at all; it’s a physical transmission path used to carry higher-frequency signals within a confined structure. Satellite communications rely on signals traveling to and from space, which introduces longer delays and is suited for long-range links, not short-range airport operations. Microwave refers to higher-frequency bands that are great for high-capacity, long-range, line-of-sight links, but for routine short-range airfield communications, VHF is the standard choice.