A High Efficiency CMOS UWB Impulse Radio Transmitter for Low Power Applications

This paper presents a high efficiency ultra-wideband impulse radio (UWB-IR) transmitter for low power applications employing binary phase shift keying (BPSK) and pulse position modulation (PPM). There are two innovations in this transmitter: single ended ring oscillator with initial phase control and balun with capacitor connected in series (BCCS). Two separated single-ended ring oscillators are employed to generate the out-phase signals, which achieve the BPSK modulation with the help of BCCS. And the BCCS also greatly suppresses the power spectrum at low frequency because it obtains third-order high pass characteristics. The measurement on chips fabricated using 0.18μm CMOS technology shows that the power consumption is 4.02mW, peak-to-peak amplitude of output impulse is about 400mV with 50Ohm load, power efficiency is 32 pJ/pulse.