Which term describes the angle between the first null points on the radiation pattern?

Which term describes the angle between the first null points on the radiation pattern?

• A. HPBW
• B. BWFN
• C. Directivity
• D. Reciprocity

Answer: (B)

The angle between the first null points on a radiation pattern is called the first-null beamwidth. This measure captures how wide the main lobe extends before the pattern falls to zero (the first nulls define its outer edges). It’s different from the half-power beamwidth, which uses the points where the power drops to half its peak and lies inside the main lobe, giving a typically smaller value. Directivity is about how concentrated the radiated power is in a given direction compared to an isotropic source, not an angular width. Reciprocity relates to the equality of transmitting and receiving properties of a passive antenna, not beamwidth. So the angle between the first nulls best describes the first-null beamwidth, often abbreviated as BWFN.

The angle between the first null points on a radiation pattern is called the first-null beamwidth. This measure captures how wide the main lobe extends before the pattern falls to zero (the first nulls define its outer edges). It’s different from the half-power beamwidth, which uses the points where the power drops to half its peak and lies inside the main lobe, giving a typically smaller value. Directivity is about how concentrated the radiated power is in a given direction compared to an isotropic source, not an angular width. Reciprocity relates to the equality of transmitting and receiving properties of a passive antenna, not beamwidth. So the angle between the first nulls best describes the first-null beamwidth, often abbreviated as BWFN.