What is a curved surface that can focus radio waves?

What is a curved surface that can focus radio waves?

• A. Satellite dishes
• B. Parabolic mirrors
• C. Lens arrays
• D. Dipole antennas

Answer: (A)

A curved surface that focuses radio waves is a parabolic reflector. The defining feature is that a paraboloid shape reflects incoming waves that are parallel to its axis toward a single focal point, so energy from a distant source can be collected or directed efficiently. A satellite dish is a common real-world example of this: its dish forms a paraboloid, and the feed horn placed at the focus collects signals reflected from the dish (or, when transmitting, sends signals that are reflected outward as a focused beam). This is why a parabolic reflector is the best way to focus radio waves. The other options don’t fit as a focusing surface in the same way. A dipole antenna is a simple radiator/receiver that doesn’t concentrate distant waves to a single point. Lens arrays rely on refraction rather than reflection and aren’t the typical means used to focus RF energy onto a single location. So the concept being tested is the parabolic reflector, with the satellite dish serving as a familiar example of that shape in action.

A curved surface that focuses radio waves is a parabolic reflector. The defining feature is that a paraboloid shape reflects incoming waves that are parallel to its axis toward a single focal point, so energy from a distant source can be collected or directed efficiently. A satellite dish is a common real-world example of this: its dish forms a paraboloid, and the feed horn placed at the focus collects signals reflected from the dish (or, when transmitting, sends signals that are reflected outward as a focused beam). This is why a parabolic reflector is the best way to focus radio waves.

The other options don’t fit as a focusing surface in the same way. A dipole antenna is a simple radiator/receiver that doesn’t concentrate distant waves to a single point. Lens arrays rely on refraction rather than reflection and aren’t the typical means used to focus RF energy onto a single location. So the concept being tested is the parabolic reflector, with the satellite dish serving as a familiar example of that shape in action.