There is provided an antenna for use in an ultra-wideband device, wherein the antenna is used as an RF radiator and as a heat sink. There is also provided a device for use in an ultra wideband network, the device comprising a component, for example an integrated circuit package, that generates unwanted heat as part of its normal operation, the device further comprising an antenna as described above placed in thermal contact with the component. The antenna may be electrically connected to one or more pins of the component. Alternatively, the antenna may be capacitively connected to the component. There is also provided a heat sink for a wireless communications device, the heat sink being shaped such that it can operate as an antenna for radio frequencies.