An Energy-Autonomous SWIPT RFID Tag for Communication in the 2.4 GHz ISM Band

This paper presents the design of an energy autonomous radiofrequency identification (RFID) tag for communication and/or indoor localization. It makes use of the energy harvesting (EH) technique in the 915 MHz ultra-high frequency (UHF) band for the feeding of a system-on-a-chip (SoC), working also as a radio transceiver, in order to communicate data to a reader, or a gateway, at 2.4 GHz. First, the design of a multiple-input multiple-output (MIMO) antenna is described, with the dimensions of the whole tag limited to 47 × 100 mm
²
. Subsequently, the description and the performance of the UHF rectifier are reported, with its connection to the related power management unit (PMU). The PMU is then connected to a transceiver that can send information about its identification number (ID) and the received signal strength indicator (RSSI) without the need of a battery.