A 0.24-nJ/b Wireless Body-Area-Network Transceiver With Scalable Double-FSK Modulation

TLDR

The authors propose resonance matching and contact impedance sensing techniques to improve the quality of the body channel. They implement an energy‑efficient WBAN transceiver in 0.18‑µm CMOS with a 1‑V supply, employing BCC PHY, double‑FSK modulation, and five low‑power circuit techniques—including a reconfigurable LNA with CIS, a current‑reuse wideband demodulator, a divider‑based LO with duty‑cycle correction, a reconfigurable driver with RM, and a divider‑based digital double‑FSK modulator. The resulting receiver and transmitter consume 2.4 mW and 2 mW at 10 Mb/s, achieving energy efficiencies of 0.24 nJ per received bit and 0.20 nJ per transmitted bit.

Abstract

An energy-efficient wireless body-area-network (WBAN) transceiver is implemented in 0.18-μm CMOS technology with 1-V supply voltage. For the low energy consumption, the body channel communication (BCC) PHY is utilized with the theoretical results of Maxwell's equation analysis behind the BCC. Based on the channel analysis, the resonance matching (RM) and contact impedance sensing (CIS) techniques are proposed to enhance the quality of the body channel. A double-FSK modulation scheme is adopted with high scalability to fulfill the IEEE 802.15.6 Task Group specifications. In addition, a low-power double-FSK transceiver is implemented by five circuit techniques: 1) a reconfigurable LNA with CIS; 2) a current-reuse wideband demodulator; 3) a divider-based local oscillator (LO) generation with duty-cycle correction in the receiver; 4) a reconfigurable driver with RM; and 5) a divider-based digital double-FSK modulator in the transmitter. As a result, fully WBAN compatible receiver and transmitter consume 2.4 and 2 mW, respectively, at a data rate of 10 Mb/s, corresponding to energy consumption of 0.24 nJ per received bit and 0.2 nJ per transmitted bit.