title: New analysis and design of a RF rectifier for RFID and implantable devices.
abstract: New design and optimization of charge pump rectifiers using diode-connected MOS transistors is presented in this paper. An analysis of the output voltage and Power Conversion Efficiency (PCE) is given to guide and evaluate the new design. A novel diode-connected MOS transistor for UHF rectifiers is presented and optimized, and a high efficiency N-stage charge pump rectifier based on this new diode-connected MOS transistor is designed and fabricated in a SMIC 0.18-μm 2P3M CMOS embedded EEPROM process. The new diode achieves 315 mV turn-on voltage and 415 nA reverse saturation leakage current. Compared with the traditional rectifier, the one based on the proposed diode-connected MOS has higher PCE, higher output voltage and smaller ripple coefficient. When the RF input is a 900-MHz sinusoid signal with the power ranging from -15 dBm to -4 dBm, PCEs of the charge pump rectifier with only 3-stage are more than 30%, and the maximum output voltage is 5.5 V, and its ripple coefficients are less than 1%. Therefore, the rectifier is especially suitable to passive UHF RFID tag IC and implantable devices.
authors.affiliation: Department of Electronic Science & Technology, Huazhong University of Science & Technology, Wuhan, 430074, China. dsliu@mail.hust.edu.cn
authors.forename: Dong-Sheng
authors.initials: DS
authors.lastname: Liu
authors.forename: Feng-Bo
authors.initials: FB
authors.lastname: Li
authors.forename: Xue-Cheng
authors.initials: XC
authors.lastname: Zou
authors.forename: Yao
authors.initials: Y
authors.lastname: Liu
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Hui
authors.forename: Xiong-Fei
authors.initials: XF
authors.lastname: Tao
mesh_terms: D004867:Equipment Design; D019736:Prostheses and Implants; D057233:Radio Frequency Identification Device; D014173:Transistors, Electronic