What must be done to prevent standing waves on a feed line connected to an antenna?
The antenna feed point must be at DC ground potential
The feed line must be an odd number of electrical quarter wavelengths long
The feed line must be an even number of physical half wavelengths long
The antenna feed point impedance must be matched to the characteristic impedance of the feed line✓Bonne réponse
Explication
Standing waves exist only where a reflected wave is present, and no reflection occurs when the load equals the line's characteristic impedance. Choosing a particular line length does not remove the reflection; it only moves the standing wave pattern along the line.