Amateur Extra › E9 Antennas and Transmission Lines › E9B01
E9B01
What is the 3 dB beamwidth of the antenna radiation pattern shown in Figure E9-1?
Pick an answer to check it.
Answer: B. 50 degrees
Beamwidth is measured between the points where the main lobe is 3 dB down from its peak. In Figure E9-1 those points are about 25 degrees either side, for a total of 50 degrees.
Tip: Measure between the -3 dB points.