Time-domain characteristics of body channel communication (BCC) and BCC transceiver design

In this paper, time-domain characteristics of human body channel communication (BCC) are measured with an analog frontend (AFE) printed circuit board (PCB) at different transmission distances and signal frequencies. In addition, a 1 Mb/s to 40 Mb/s wideband signaling (WBS) BCC transceiver which uses the human body skin as a transmission medium is presented. As compared to wireless transmission methods, BCC is more stable and has less power attenuation. Furthermore, it is almost insensitive to the motion of the human body. However, the body antenna effects cause interferences in human body channel communication. In the proposed transceiver, at the transmitter part, the NRZI-encoded data are sent directly to the human body channel. At the receiver part, after an AFE PCB amplified the received signals, the proposed 7X oversampling clock and data recovery (CDR) circuit recovers the data with random jitter and frequency drift tolerance. The proposed WBS BCC transceiver is implemented in a standard performance 90nm CMOS process, and the core area is 0.144 mm2. The power consumption of the WBS BCC transceiver is 1.21mW at 40Mb/s, and the bit energy is 0.03 nJ/b.