Basic Qualification · B-006 Feedlines and antenna systems · B-006-001-011
What factors determine the characteristic impedance of a coaxial transmission line?
- A The ratio of the diameter of the outer shield to the diameter of the inner conductor
- B The diameter of the shield and the length of the line
- C The diameter of the shield and the frequency of the signal
- D The frequency of the signal and the length of the line
Correct answer: A — The ratio of the diameter of the outer shield to the diameter of the inner conductor. From the official ISED question bank, verified word for word.
Why
The characteristic impedance of a coaxial cable is set by its physical build, specifically the ratio of the outer shield's diameter to the inner conductor's diameter. The full explanation — and one for every question — is in Pro.
Practise this section
Getting the signal out: antennas, feedlines, SWR, baluns, matching, and why antenna length depends on frequency.