A Pulse-Based Ultra-Wideband Transmitter in 90-nm CMOS for WPANs

This paper describes the design of a pulse-based ultra-wideband (UWB) transmitter for wireless personal area networks (WPANs). The transmitter consists of a pulse generator, a phase-locked loop (PLL), and modulation circuitry. All of the components except the transmit antenna and the reference clock source are integrated. The pulse generator employs on-chip finite-impulse response (FIR) filtering so that the transmitted signal is compliant with the indoor FCC spectral emission limits. The frequency-multiplying PLL is included to provide a stable clock that sets the tap delays of the FIR filter. The transmitter architecture is capable of providing simultaneous binary phase shift keying (BPSK) and pulse position modulation (PPM). Implemented in a 90-nm standard digital CMOS process, the 2.83 mm² prototype transmitter achieves a maximum pulse rate of 1.8 Gpulses/s while dissipating 227 mW from a 1-V supply. The measured jitter at the output of the PLL is 1.9 ps_rms and 15.1 ps_pp.