The aim of this invention is to improve the structures both in terms of operating effectiveness, in particular ways of matching the antenna and a generator, and in terms of overall size.

The antenna combines a plurality of radiating elements each capable of operating in transmission or in reception at its natural mode at frequencies that are different and independent, without increasing the overall volume of the antenna compared with dispositions known in the prior art. The present invention thus makes it possible to obtain an antenna of relatively small size compared with its working wavelength(s).