0.36 nJ/bit MedRadio Band OOK Transmitter for Wearable Healthcare Applications

In this paper, an energy efficient low power on-off keying (OOK) transmitter (TX) is proposed for wearable healthcare applications. TX is suitable for biosignal communication from wearable healthcare devices (WHD) in Federal Communication Commission recommended 400 MHz Medical Device Radiocommunication band. The proposed TX uses the principle of edge combination for low power RF carrier generation. The proposed TX has been implemented in 180 nm mixed-mode CMOS technology. Measurements were done with a custom designed test chip. Measurement results show that in OOK mode the proposed TX achieves an energy efficiency of 0.36 nJ/bit. TX consumes an average power of 71 µW and radiates about -24 dBm power at 200 kb/s. Successful wireless communication of pseudo random bit sequence is also shown with the TX and a commercial off-the-shelf receiver at a data rate of 200 kb/s for a maximum communication distance of 2 m.