Advanced Qualification · A-007 Feedlines and matching · A-007-005-003
Which of these antennas does not produce circular polarization?
- A Crossed dipoles fed 90 degrees out of phase
- B Lindenblad antenna
- C Axial-mode helical antenna
- D Loaded helical-wound antenna
Correct answer: D — Loaded helical-wound antenna. From the official ISED question bank, verified word for word.
Why
A loaded helical-wound antenna typically radiates linear polarization because the loading coils are added to electrical lengthen the wire without changing its fundamental straight-wire shape or creating the necessary phase shift for circular waves. 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.