Portable radio equipment which is thin enough to enhance portability and, yet, has a sufficiently high antenna gain. The equipment has an antenna which is made up of a pair of metal plates located face-to-face, and a short-circuiting member for short-circuiting the metal plates. A circuit board loaded...http://www.google.es/patents/US5079559?utm_source=gb-gplus-sharePatente US5079559 - Dual plate antenna
