A Supply-Rail-Coupled eTextiles Transceiver for Body-Area Networks

This paper presents a transceiver that communicates over electronic textiles as an alternative, energy-efficient communication medium for body-area network (BAN) applications. The proposed eTextiles network architecture consists of a two-wire conductive yarn medium, body-worn nodes, and a basestation used for data collection and medium-access control. Fabricated in 0.18 μm CMOS technology, the eTextiles transceiver employs supply-rail-coupled differential signaling to efficiently time-share the eTextiles medium between communication and remote charging activities. Remote charging achieves up to 96% power transfer efficiency when a basestation battery is used to charge remote ultra capacitors, which are used as the power supplies of body-worn nodes. Operating at 0.9 V and at 10 Mb/s, the receiver and transmitter front-ends together consume 3.2 pJ/bit over 1 m, which is at least 20X more efficient than conventional BAN receiver front-ends. The transceiver also contains an integrated digital baseband and medium access controller, which, together with the receiver front-end, consume 110 μW during continuous operation.