Design of Integrated Ultra-Low-Power Rectifiers for Passive RFID-Tags at UHF Frequencies

Abstract:
Over the past few years, there has been a growing demand for wireless short range communication devices, which can be realized and maintained under extremely low costs. Recently, passive radio frequency identification (RFID) has gained a lot of interest, because it is a well known synonym for integrated low cost identification and sensor devices. The passive RFID technology is mainly advanced by the increase of the operation distance and improvements regarding the operational reliability. In order to achieve this aim, efficient energy scavenging concepts and the design of integrated circuits with an ultra-low power consumption are an emerging task. State of the art passive RFID tags use the RF power of the interrogator as an ambient power source. For high operation distances it is necessary to provide RF to DC conversion circuits, which can handle ultra-low-power levels. In this paper a rectification circuit for ultra-low-power conversion is systematically analyzed. Furthermore, the influences of typical parasitic effects given by CMOS bulk technologies are verified by non-linear simulations with a commercially available harmonic balance simulator.