A Sub-GHz Mostly Digital Impulse Radio UWB Transceiver for Wireless Body Sensor Networks

This paper presents a mostly digital impulse radio (IR) ultra-wideband (UWB) transceiver for low power wearable and implantable biomedical devices. The UWB transmitter adopts carrier-less all-digital pulse generator with on-off keying (OOK) modulation, and uses an 11-bit Barker code for reliable communication in the frequency range of 0-960 MHz. The receiver is based on auto-threshold detection. The only RF block in the receiver is the low-noise amplifier (LNA), and this LNA operates intermittently for better power efficiency. The timing window for incoming data is provided by a delay locked loop (DLL). This DLL could synchronize the receiver clock to the incoming data. Fabricated in a standard 0.35- μm CMOS technology, the prototype chip achieves energy efficiency of 100 and 600 pJ/pulse for the transmitter and receiver, respectively.