Which of the following factors determine the characteristic impedance of a parallel conductor feed line?
The distance between the centers of the conductors and the radius of the conductors✓Correct answer
The distance between the centers of the conductors and the length of the line
The radius of the conductors and the frequency of the signal
The frequency of the signal and the length of the line
Explanation
The characteristic impedance of a parallel-conductor line is fixed by its cross-sectional geometry, namely the center-to-center spacing and the conductor radius, together with the dielectric. It does not depend on line length or on operating frequency.