摘要 |
A dual band transmission device includes a microstrip antenna. Its patch is provided with a short circuit for setting up quarter-wave resonant modes. A slot penetrates into the patch from its periphery, in the vicinity of the short circuit, and separates a first region from a second region, which second region nevertheless remains connected to the first region by a passage. Two resonant modes are obtained, one in the first region and the other in the first region, the passage and the second region. They can be excited from a common connecting line. According to the invention, the center frequencies and the pass-bands of the two modes are adjusted by means of a reactive component such as a capacitor which couples the first region to the second region in the vicinity of the origin of the slot. The invention applies in particular to producing a dual mode mobile telephone system conforming to the GSM and DCS standards. |