A 29pJ/bit FSK transmitter for WBAN applications

A low power, 5-Mb/s fully integrated body channel Frequency Shift Keying (FSK) transmitter using the human body as a signal transmission medium is designed for medical data transmission in body area network. The FSK transmitter has a 9-bit digitally controlled injection locked ring oscillator in place of the power consuming Phase-Locked Loop (PLL) to achieve low energy consumption and ultra wide-band tuning range. 30 MHz to 120 MHz band is used by the body channel transmitter to overcome the body antenna effect. A multiple injection lock modulation scheme is proposed for the 5-Mb/s FSK. The chip is implemented with a 0.18-μm CMOS process using 1.2-V supply. When working at 5 Mb/s, the transmitter core power consumption is only 146.64 μW.