Extra exam question E9D08
Subelement E9, ANTENNAS AND TRANSMISSION LINES· Group E9D
What happens as the Q of an antenna increases?
- A.SWR bandwidth increases
- B.SWR bandwidth decreases (correct answer)
- C.Gain is reduced
- D.More common-mode current is present on the feed line
WhyAs an antenna's Q increases, its SWR bandwidth decreases. As an antenna's Q increases, its SWR bandwidth decreases, since a higher Q always means a narrower range of frequencies over which the antenna's impedance stays close enough to the feed line's characteristic impedance for an acceptable match, answer B. SWR bandwidth doesn't increase with rising Q, and increasing Q isn't inherently what reduces gain or increases common-mode feed line current, those are separate, unrelated effects.
Published 2026-08-28 · Last updated 2026-08-28 · Question text is verbatim from the 2024-2028 NCVEC Element 4 pool (public domain); the explanation above is original writing, see our methodology.
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