Antenna having internal and external structures

The present technology provides an improved antenna having a conductive first plate, a conductive second plate and a conductive third plate. The conductive first plate and the conductive second plate are disposed and have an electrical connection to form an external antenna structure having a U-shaped cross section. The conductive third plate is disposed parallel to the conductive first plate between the conductive first plate and the conductive second plate and has a proximate edge proximate the electrical connection. The conductive third plate has an electrical length with respect to the proximate edge corresponding to an odd integer multiple of a quarter of a guide wavelength associated with a resonant frequency of the antenna. The conductive third plate forms part of an internal antenna structure.