Basic Qualification · B-006 Feedlines and antenna systems · B-006-004-010
Si la fréquence d'exploitation augmente, comment la perte de la ligne de transmission change-t-elle?
- ALa perte augmente en raison de l'augmentation de la vélocité des ondes
- BLa perte diminue, en raison de l'effet pelliculaire ("skin effect")
- CLa perte diminue, en raison de la diminution du ROS
- DLa perte augmente en raison des pertes internes de la ligne
Correct answer: D — La perte augmente en raison des pertes internes de la ligne. Question tirée de la banque officielle d'ISDE.
Why
When you raise the operating frequency, the electrical resistance inside the cable goes up because the signal tends to flow only on the outer surface of the wire, a phenomenon called skin effect. 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