Extra exam question E9B04
Subelement E9, ANTENNAS AND TRANSMISSION LINES· Group E9B
What is the front-to-back ratio of the radiation pattern shown in Figure E9-2?
- A.15 dB
- B.28 dB (correct answer)
- C.3 dB
- D.38 dB
WhyThe radiation pattern shown in Figure E9-2 has a front-to-back ratio of about 28 dB. Front-to-back ratio in Figure E9-2 compares the main forward lobe, which peaks near the 0 dB reference at a shallow elevation angle, to the response near 180 degrees (the rear direction), which is suppressed down to around the -28 dB level in this pattern, giving a front-to-back ratio of about 28 dB, answer B. The other figures don't match the actual gap between the main lobe's peak and the rear-direction response shown on this chart.
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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