I have read everything I can find about monopole (vertical antenna) radials, and also watched many YouTube videos that touch on the topic. I see conflicting information about what they do, where a particular article or video tends to fall into one of two camps:
- Radials are used to increase the conductivity of the ground surrounding a vertical antenna, to aid in returning current efficiently to the transmitter.
- Radials create a mirror-like reflection around the vertical antenna, which reflects radio waves that hit the ground off at an angle that simulates an "image antenna" beneath the surface, as though it were a vertical dipole instead of a monopole.
I can't find any resources that brings these 2 things together, so I'm left confused about how radials work from a physics standpoint.
How do radials work?
P.S. explanation #1 further confuses me because I'd expect that we don't want to "capture" the energy from the radiated signal and return it to the transmitter, since we want it to radiate! So if #1 turns out to be the true purpose of radials, I'd love to have that clarified as well.
EDIT: Anyone else who has this question, here's the best video I found that really gave me an "a hah" moment as to what's happening with the ground around a vertical antenna and why radials help (I recommend entire video, but I started it at the most relevant part):