The present invention refers to an antennaless wireless handheld or portable device comprising a communication module including a radiating system capable of transmitting and receiving electromagnetic wave signals in a first frequency region and in a second frequency region, wherein the highest frequency of the first frequency region is lower than the lowest frequency of the second frequency region. The radiating system comprising a radiating structure and at least one internal port, wherein the input impedance of the radiating structure at the/each internal port when disconnected from the radiofrequency system has an imaginary part not equal to zero for any frequency of the first frequency region; and wherein said radiofrequency system modifies the impedance of the radiating structure, providing impedance matching to the radiating system in the at least two frequency regions of operation of the radiating system.