13.56MHz RF front-end for Body Sensor Network

• Main Authors: Jing Yang Kung, 龔靖洋
• Other Authors: Shuenn-Yuh Lee
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/86895125952550626409

碩士 === 國立中正大學 === 電機工程研究所 === 99 === Our research addresses the problem of implementing a 13.56MHz RF front-end circuit for the Body Sensor Network. The front-end circuits include a full-wave bridge rectifier, a linear regulator, a BPSK demodulator and a clock／data separator. The main function of the proposed 13.56MHz RF front-end batteryless circuit is to provide the Body Sensor Network power and control signals correctly, while the power and control signals are received from an external device. An external device can send their control signals with a 4.5KHz clock signal and a Manchester encoding signal according to the XOR operation of input signals of clock and data. The transmitted signals are modulated by BPSK with a 13.56MHz carrier. The implanted chip receives this 13.56MHz RF signal by an internal coil, hence a front-end circuit is required to pre-process the received signal. The power is created by using a full-wave bridge rectifier to convert the AC of the BPSK signal to DC voltage. Becuase the received AC power is unstable, a linear regulator is adopted to stabilize the DC voltage at 1.8V and provides the power for the back-end circuits. The control signals will be extracted by BPSK demodulator, then a 4.5KHz clock and data can be obtained by demodulation circuits. This chip is implemented in TSMC 0.18µm 1P6M CMOS process. The overall chip area is 1.183x1.143 mm2 under the power consumption of 632μW.