Abstract: A multifrequency microstrip antenna in accordance with the present invention includes two zones connected to a short-circuit consisting of two conductive strips. These zones are sufficiently decoupled from each other to enable two resonances to be established in two respective different areas formed by the zones. The resonances are at least approximately of the quarter-wave type and each has an electric field node fixed by the short-circuit. The same coupling device is used to excite the two resonances. The invention applies in particular to portable telephones and to their base stations.

Abstract: A quarter-wave antenna includes a patch and a ground respectively formed on the two surfaces of a substrate and mutually connected by a short-circuit. A coupling strip enters the patch via said short-circuit. It extends in the patch between two lateral slots and is connected thereto at an internal point to enable resonance of the antenna to be excited. According to the invention, the lateral slots are sufficiently narrow for a lateral coupling effect to contribute to excitation of the antenna from the edges of the strip. The invention applies in particular to mobile telephones.