This paper presents a compact antenna solution able to perform communication and RF energy harvesting functionalities, in order to fulfill the future wireless network requirement of simultaneous wireless information and power transfer. The system is thought for next generation passive RFID tags: it combines a single-port antenna and a diplexer, both designed on paper substrate to operate in the European UWB and UHF bands, for communication/localization and energy harvesting purposes, respectively. The impact of the antenna layout on system performance is discussed, from both communication and energy harvesting points of view.