J-pole antenna
The J-pole antenna consists of a short and a long vertical pole with a feed point near the bottom. The antenna looks like the letter J, hence the name J-pole antenna.
Formulas
![Schematic](/media/schematics/j-pole-antenna.png)
![](/shared/media/generated/083073465e96.png)
![](/shared/media/generated/21406e5b391f.png)
![](/shared/media/generated/d2fb4975c2c5.png)
![](/shared/media/generated/3d2bea227484.png)
l is the symbol for length and is measured in meter (m).
f is the frequency in megahertz (MHz).