Basic Qualification · B-006 Feedlines and antenna systems · B-006-009-006
Quel est le gain approximatif d'une antenne dipôle demi-onde en espace libre ("free space") par rapport au rayonnement d'une antenne isotrope?
- A1,0 dB
- B2,1 dB
- C1,5 dB
- D3,0 dB
Correct answer: B — 2,1 dB. Question tirée de la banque officielle d'ISDE.
Why
A half-wave dipole concentrates radio energy slightly better in its favoured directions than an imaginary isotropic radiator, which radiates equally in all directions. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and antenna systems is section B-006 of the Basic exam: Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.
Drill B-006 — free, no account