Patent ID: 6218990
Filing Date: 2001-04-17
Classification: H01Q

Abstract:
A dual frequency radiocommunication device including:a signal processor unit adapted to be tuned to a frequency near at least two predetermined frequencies to transmit and/or receive an electric signal at each of those two frequencies; anda microstrip antenna connected to that processor unit to couple said electric signal to radiated waves, said antenna having a patch with a front edge, a rear edge and two lateral edges joining said front and rear edges, said rear edge provided with a short-circuit setting up a quarter-wave resonance in said antenna with an electric field node fixed by the short-circuit and a resonance path extending between said rear edge and said front edge, a distance between said front and rear edges being such that said resonance path between said front and rear edges has a quarter-wave resonant frequency which is one of said predetermined frequencies;wherein a distance between said two lateral edges is such that a path extending between said two lateral edges has a half-wave resonant frequency which is the other of said predetermined frequencies.