Radar beam width is defined by which points?

Radar beam width is defined by which points?

• A. Half-power points
• B. Peak intensity
• C. Side-lobe level
• D. Main lobe width

Answer: (A)

Beam width is defined by the angular separation between the directions where the radiated power falls to half of its maximum value. Those points are the -3 dB, or half-power, points, and the angle between them is the standard measure of the main lobe’s width (HPBW). Since power is proportional to the square of the field, dropping to half the peak corresponds to a specific, consistent width choice. The other concepts don’t define width: peak intensity is the maximum value itself, not its spread; side-lobe level concerns the relative height of secondary lobes rather than where the main lobe ends; and while “main lobe width” is used informally, the conventional definition relies on the half-power points to give a precise, comparable measure.

Beam width is defined by the angular separation between the directions where the radiated power falls to half of its maximum value. Those points are the -3 dB, or half-power, points, and the angle between them is the standard measure of the main lobe’s width (HPBW). Since power is proportional to the square of the field, dropping to half the peak corresponds to a specific, consistent width choice.

The other concepts don’t define width: peak intensity is the maximum value itself, not its spread; side-lobe level concerns the relative height of secondary lobes rather than where the main lobe ends; and while “main lobe width” is used informally, the conventional definition relies on the half-power points to give a precise, comparable measure.