What is Main Beam (Main Lobe) in radar terminology?

• A. The widest spread beam
• B. A secondary faint radiation
• C. The central region used for alignment
• D. The primary, strongest beam used for target detection

Answer: (D)

The main beam, or main lobe, is the central portion of the antenna’s radiation pattern where the transmitted power is concentrated most strongly. It marks the direction in which the radar sends the most energy, and it’s where the received echoes are expected to be strongest for target detection. This is why it’s the primary beam used for searching and bearing estimation. Other parts of the pattern—side lobes and back lobes—carry less energy and can cause clutter or false returns, but they’re not relied upon for reliable detection. The idea of the widest spread is incorrect because the main beam is the focused, high-gain direction, not the broadest spread.