Here is a video explaining RF ground, by Michael Martens (KB9VBR).
Today we talk about the RF ground, what it is and when it’s necessary. The purpose of the RF ground is to act as a reflector. It doesn’t radiate RF energy, but instead interacts with the antenna’s radiating elements by mirroring and reflecting that energy, creating a predictable RF radiation pattern. So the RF ground is important, right. Then why doesn’t every antenna require one? Well they do, but just not in a way that might seem obvious. Continue watching for more. . .