A 5.3 µW contact monitoring sensor with BCC electrode and MICS antenna for energy efficient unified WBAN transceiver

A low power contact monitoring sensor for an energy efficient implantable and wearable wireless body-area-network (WBAN) transceiver is implemented in 0.18 μm CMOS process. The transceiver utilizes 30 - 70 MHz for the body channel communication (BCC) and 402 - 405 MHz for the medical implant communication service (MICS) with a pattern-printed electrode interface for operating as both BCC electrode and MICS antenna. The contact monitoring sensor adopts the reflection wave detection technique to compensate for the channel quality degradation due to the variation of the contact distance between the electrode and the human body. The reflection wave detection is achieved by an energy efficient envelope detector and a 2-bit ADC with a programmable reference voltage. It leads to mitigate both the linearity and sensitivity requirements of the receiver front-end by more than 10 dB. As a result, with the power consumption of 5.3 μW, the proposed contact monitoring sensor reduces the power consumption of the LNA more than 70%.