Amateur Extra › E9 Antennas and Transmission Lines › E9C01
E9C01
What type of radiation pattern is created by two 1/4-wavelength vertical antennas spaced 1/2-wavelength apart and fed 180 degrees out of phase?
Pick an answer to check it.
Answer: D. A figure-eight oriented along the axis of the array
Two verticals a half wavelength apart fed 180 degrees out of phase reinforce along the line joining them and cancel broadside. The result is an end-fire figure-eight along the array axis.
Tip: Half wave, out of phase: end-fire figure-eight.