Advanced Qualification · A-007 Feedlines and matching · A-007-005-002
What type of polarization is produced by crossed dipoles fed 90 degrees out of phase?
- A None of the other answers, the two fields cancel out
- B Circular polarization
- C Cross-polarization
- D Perpendicular polarization
Correct answer: B — Circular polarization. From the official ISED question bank, verified word for word.
Why
When two dipoles are crossed and fed with signals 90 degrees out of phase, the resulting radio wave rotates as it travels, creating a corkscrew motion known as circular polarization. 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.