Advanced Qualification · A-007 Feedlines and matching · A-007-005-005
For VHF and UHF signals over a fixed path, what extra loss can be expected when linearly-polarized antennas are crossed-polarized (90 degrees)?
- A 6 dB
- B 10 dB
- C 20 dB or more
- D 3 dB
Correct answer: C — 20 dB or more. From the official ISED question bank, verified word for word.
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 at the advanced level: transmission line theory, impedance transformation, stubs and matching networks.