Basic Qualification · B-006 Feedlines and antenna systems · B-006-009-002
How can the directivity of a half-wave dipole be increased?
- A By adding traps to the radiating element
- B By lengthening the radiating element
- C By adding one or more parasitic elements
- D By using a radiating element with a larger diameter
Correct answer: C — By adding one or more parasitic elements. From the official ISED question bank, verified word for word.
Why
Adding one or more parasitic elements, which are extra metal rods that do not connect to the feedline, reshapes the signal pattern to focus energy in one direction, thereby increasing directivity. 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.