Inverted F

The Inverted F is distiguished by the loop formed by the Ground enclosed box formed by the short right angle elements of the letter F. The picture at the left says far more. This is a low, long antenna roughly quarter wavelength from the ground point, up to the bend, out to the end. The drive point was found by trial and error.
Gain various between 3 and 3.5 dBi and evenly distrubuted throughout a hemi-spherical region. This is the product of employing a "perfect" ground in analysis. UHF applications may approach this behavior.
Because of the sheet metal form, this qualifies as a thick radiator. The SWR curve on the left confirms this when compared to the SWR curve below.
This is the SWR curve for a one wire model of the design modeled here.