The present invention refers to an antennaless wireless handheld or portable device (100) comprising: a user interface module (101), a processing module (102), a memory module (103), a communication module (104) and, a power management module (105); the communication module (104) including a radiating system (200) 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; said radiating system (200) comprising a radiating structure (201) comprising or consisting of at least one ground plane layer (206) capable of supporting at least one radiation mode, the at least one ground plane layer (206) including at least one connection point (207); at least one radiation booster (204) to couple electromagnetic energy from/to the at least one ground plane layer (206), the/each radiation booster including a connection point (205); and at least one internal port (208), wherein the/each internal port (208) is defined between the connection point (205) of the/each radiation booster (204) and one of the at least one connection point (207) of the at least one ground plane layer (206); wherein the at least one ground plane layer (206) has associated a ground plane rectangle (450), the ground plane rectangle (450) being defined as the minimum-sized rectangle that encompasses the at least one ground plane layer (206) so that the sides of the ground plane rectangle (450) are tangent to at least one point of the at least one ground plane layer (206); the radiating system (200) further comprising a radiofrequency system (202), and an external port (203); the radiofrequency system (200) comprising a port (209) connected to each of the at least one internal port (208) of the radiating structure (201) and a port (210) connected to the external port (203) of the radiating system (200); wherein the input impedance of the radiating structure (201) at the/each internal port (208) when disconnected from the radiofrequency system (202) has an imaginary part not equal to zero for any frequency of the first frequency region; and wherein said radiofrequency system (202) modifies the impedance of the radiating structure (201), providing impedance matching to the radiating system (200) in the at least two frequency regions of operation of the radiating system.