A Low-Power Baseband ASIC for an Energy-Collection IR-UWB Receiver

This paper reports on the realization and the characterization of an application-specific integrated circuit (ASIC) intended for the processing of impulse radio ultra-wideband (IR-UWB) baseband signals. The incoming baseband signals result from the direct down-conversion of IR-UWB radio-frequency pulses, which are modulated by a binary frequency-shift keying (BFSK) scheme. The realized mixed-signal integrated circuit features an analog demodulation based on the quadricorrelation method, a non-coherent pulse detector using an integrate-and-dump operation and a bit-level synchronization digital circuit. An novel acquisition algorithm intended for low duty-cycled IR-UWB signals enabling a signal-to-noise ratio (SNR) estimate is proposed. The baseband ASIC is able to demodulate, acquire and decode BFSK IR-UWB signals. It requires 13 mW of supply power during the initial acquisition and 6.5 mW during the signal tracking phase at a pulse repetition rate (PRR) of 5 MHz. The circuit is fabricated in a 0.18-mum CMOS technology.