Basic Qualification · B-006 Feedlines and antenna systems · B-006-011-008
What does "antenna front-to-back ratio" mean in reference to a Yagi antenna?
- A The ratio of the power radiated in the forward direction to the power radiated in the opposite direction
- B The ratio of the power radiated by the director element, to the power radiated by the reflector element
- C The ratio of the length of the director element, to the length of the reflector element
- D The ratio of the driven element-to-director spacing, to the driven element-to-reflector spacing
Correct answer: A — The ratio of the power radiated in the forward direction to the power radiated in the opposite direction. From the official ISED question bank, verified word for word.
Why
The ratio of the power radiated in the forward direction to the power radiated in the opposite direction is right because a Yagi antenna is designed to focus energy like a spotlight, sending most signal ahead while rejecting signals coming from behind. The full explanation — and one for every question — is in Pro.
Practise this section
Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.