Advanced Qualification · A-007 Feedlines and matching · A-007-005-005
Sur un lien VHF/UHF avec antennes de polarisation linéaire entre points fixes, quelle est la perte supplémentaire provoquée par une transpolarisation ("cross-polarization") de 90 degrés?
- A20 dB ou plus
- B3 dB
- C6 dB
- D10 dB
Correct answer: A — 20 dB ou plus. Question tirée de la banque officielle d'ISDE.
Why
When a transmitting antenna sends a signal with one polarization, such as vertical, and the receiving antenna is turned 90 degrees to horizontal, the two are crossed-polarized. The full explanation — and one for every question — is in Pro.
Practise this section
Feedlines and matching is section A-007 of the Advanced exam: Feedlines and matching at the advanced level: transmission line theory, impedance transformation, stubs and matching networks.
Drill A-007 — free, no account