How does antenna beamwidth influence bearing resolution?

• A. Narrow beamwidth improves bearing resolution; wide beamwidth reduces resolution and can cause targets to merge.
• B. Beamwidth does not affect bearing resolution.
• C. Wider beamwidth improves resolution.
• D. Narrow beamwidth increases radar clutter.

Answer: (C)

Bearing resolution is about how finely you can distinguish two targets by their direction. The antenna beamwidth sets the angular size of the area the radar is effectively “looking through” at once. When the beam is narrow, this angular footprint is small, so two targets that are close in bearing fall into separate parts of the beam and return echoes that the radar can separate as distinct bearings. If the beam is wide, both targets often lie inside the same illuminated sector, their echoes blend, and you can’t tell their bearings apart. So, narrower beamwidth improves bearing resolution because you get a finer angular discrimination, while a wider beamwidth degrades it and can cause targets to merge. In practice, angular resolution is roughly on the order of the beamwidth (often the half-power beamwidth) of the antenna.