RF power harvesting system for RFID applications in multiband systems

This paper presents the RF power harvesting system. The design goes through three major phases. In the first phase, dual band antenna is designed that operates in GSM900 and WiFi 2.45 GHz bands. This is a dual band dual feed antenna that provides excellent frequency response and fairly omni directional radiation pattern. In the second phase, rectenna design is carried out to convert received RF power into DC voltage. Impedance matching and power combining included in the circuit here ensures maximum power transfer to the passive RFID chip and the rectifying circuitry. Nonlinear effects of the rectifier element are also studied and included in the co-simulation. Third phase consists of co-simulation to mitigate any integration issues of first and second phase. The final integrated system provides RF-to-DC conversion efficiency around 30% at 2.45 GHz. A sufficient isolation is provided at both frequencies to support an RFID communication and at the same time, harvesting from the 2.45 GHz band.