Antenna having external and internal structures

摘要

An antenna comprising a conductive first plate (301), a conductive second plate (310) and a conductive third plate (313, 413). The conductive first plate and the conductive second plate have an electrical connection such as a back plate (303) and form an external antenna structure (3) having a substantially U-shaped cross section. The conductive third plate is substantially parallel to the conductive first plate between the conductive first plate and the conductive second plate and has a proximate edge (3131, 4131) proximate the electrical connection. The conductive third plate has an electrical length with respect to the proximate edge corresponding to substantially an odd integer multiple of a quarter of a guide wavelength associated with an antenna resonant frequency. The conductive third plate forms part of an internal antenna structure (4, 5). The internal antenna structure may also include a conductive fourth plate (415), parallel to the third plate.