Ultra-low-power UWB for sensor network applications

Long distance, low data-rate UWB communication for sensor network applications requires a highly energy efficient transceiver combined with circuit and system-level optimizations to maximize range. A custom pulsed-UWB transceiver chipset in 90 nm CMOS is presented that targets these aggressive specifications. The transceiver efficiently communicates at data rates from 0-to-16.7 Mbps in three 550 MHz-wide channels in the 3.1 to 5 GHz band by using pulse position modulation (PPM). The transmitter uses an all-digital architecture and calibration technique to synthesize pulses with programmable width and center frequency. The non-coherent receiver operates at 0.65 V and performs channel selection Altering, energy detection, and bit-slicing. As FCC regulations limit the maximum transmit power of UWB communication, a run-length limiting technique is presented to reduce energy requirements when maximizing range at low data rates.