Answer to Question #155438 in Optics for Afraid

Question

Beamwidth (between first nulls) will be for an antenna at 3 MHz with directivity of 100

Answer 1

Find the beamwidth:

$$B=\frac{140\lambda}{D}=\frac{140c}{100f}=\frac{140\cdot3\cdot10^8}{100\cdot3\cdot10^6}=140°.$$