A horizontal array capable of quickly changing the direction of maximum radiation by changing phasing lines
An end-fed half-wavelength dipole✓Correct answer
An omni-directional antenna commonly used for satellite communications
A vertical array capable of quickly changing the direction of maximum radiation by changing phasing lines
Explanation
The Zeppelin antenna is a half-wave radiator fed at one end rather than at the center, originally through open-wire line trailed from an airship. Feeding at the end means feeding at a voltage maximum, so the feed point impedance is very high.