Design and Optimization of Power Rectifiers for Passive RFID Systems in Monolithic CMOS Circuit

This study analyzes the most fundamental constraint of RFID systems that is power rectification. This issue plays an important role in the development of long range RFID systems especially the passive RFID system. Rectifiers are the key components in power rectification and efficiency of any RFDD system. This paper concentrates in investigating this major issue. Therefore, to tackle the major problem that affects the efficiency of RFID system, this study proposed Schottky barrier diode model in standard CMOS fabrication process. The proposed SBD provides good power conversion rate and switching properties. In order to reduce the series resistance of Schottky contact, interdigitating fingers of Schottky diode layout has been adopted. The parameters of Schottky barrier diode such as saturation current, series resistance, junction capacitance, breakdown voltage and Schottky barrier height have also been optimized. Then the UHF rectifying circuit uses these SBDs to measure conversion efficiency of the SBD at RF frequency of 915 MHz.