What type of reflector is used to shape the radar beam?

• A. Flat
• B. Cylindrical
• C. Spherical
• D. Parabolic

Answer: (D)

Parabolic reflectors shape the radar beam because their curved surface converts energy from a feed located at the focus into a highly directional, narrow beam. Placing the feed at the paraboloid’s focus causes the reflected waves to emerge as a collimated, plane-wave-like beam in the far field, giving high gain and a well-defined beamwidth. Flat reflectors simply redirect energy without focusing, so they don’t produce a tight directional beam. Cylindrical reflectors focus in one dimension, creating a fan-shaped beam that’s narrow in one plane but wide in the other, not a symmetric narrow beam. Spherical reflectors can focus, but they introduce aberrations and are less efficient for producing a clean, narrow beam. Parabolic geometry provides the best combination of focus and directivity for shaping the radar beam.