plane 905 this distance between the location of the radiation boosters 901 903 and the corner of the ground plane 905 is adjusted to optimize electromagnetic behavior such as the correlation and isolation fig1 shows a similar embodiment as that in fig9 but in this case the radiation boosters are located at the four corners of a substantially rectangular ground plane of a wireless handheld or portable device such as a handset phone fig1 12 and 13 depict several embodiments of mimo systems comprising radiation boosters including slots 1106 1205 1206 1302 on the ground plane 1105 1207 1304 the size of the slots 1106 1205 1206 1302 and their relative arrangement with respect to the ground plane 1105 1207 1304 and to the radiation boosters are advantageously selected either for enhancing the impedance bandwidth or for increasing the isolation between radiation boosters so as to decrease the correlation coefficient both effects can be obtained at the same time furthermore the slot can be reused as a radiation booster if its input impedance presents a reactive behavior for the frequencies of at least one frequency band of operation of the wireless handheld or portable device or as an antenna element if it features resonant dimensions for at least one frequency belonging to a frequency band of operation of the wireless handheld or portable device as is the case of the slot 1302 which resonates in a particular frequency associated to the frequency band where the standard gsm1900 pcs is allocated in a particular example the radiation booster 1101 and 1102 are connected to a radiofrequency system 400 a similar to that shown in fig4 a so as to provide operation in the communication standards gsm850 gsm900 gsm1800 dcs.