Basic Qualification · B-006 Feedlines and antenna systems · B-006-008-005
L'ajout d'une inductance en série à une antenne aurait pour effet:
- Ad'augmenter sa largeur de bande utile
- Bde diminuer le captage de bruit atmosphérique
- Cde diminuer sa fréquence de résonance
- Dd'augmenter sa fréquence de résonance
Correct answer: C — de diminuer sa fréquence de résonance. Question tirée de la banque officielle d'ISDE.
Why
Adding a series inductance to an antenna acts like adding weight to a spring, making the system slower to oscillate and therefore lowering the resonant frequency. 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