IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 41, NO. 7, JULY 2006 1551 Single-Chip CMOS Pulse Generator for UWB Systems Lydi Smaïni, Member, IEEE, Carlo Tinella, Didier Hélal, Member, IEEE, Claude Stoecklin, Laurent Chabert, Christophe Devaucelle, Régis Cattenoz, Nils Rinaldi, and Didier Belot Abstract—This paper presents a single-chip pulse generator de- veloped for Ultra Wide Band (UWB) wireless communication sys- tems based on impulse radio technology. The chip has been inte- grated in a CMOS 130-nm technology with a single supply voltage of 1.2 V. The basic concept is to combine different delayed edges in order to form a very short duration “logical” pulse, and then filter it, so as to obtain an UWB pulse. It is possible to vary the output pulse shape, and thus the corresponding spectrum, just by acting on the delayed edge combination. Furthermore, the pulse generator supports both position modulation (2-PPM) and polarity modulation (BPSK modulation) in order to convey data through the air. Its power consumption remains less than 10 mW for a raw data rate of up to 160 Mb/s. Spectral and temporal measurements of the single-chip pulse generator are presented with an illustration of the modulation effects on the power spectral density (PSD). Index Terms—Binary phase shift keying (BPSK), CMOS tech- nology, impulse radio, polarity modulation, position modulation, PPM, pulse generator, ultra-wideband. I. INTRODUCTION T HE last decade has witnessed a tremendous growth in wire- less technologies. Ultra Wide Band (UWB) [1], [2] has emerged as one of the most promising wireless systems lately, its main foreseen applications being very high data rate short- range communication, and low data rate communication cou- pled to localization (e.g., for sensor networks), targeting both low cost and low power implementations. The American Federal Communications Commission (FCC) defines UWB as a spread spectrum wireless communication system having bandwidth at least 25% greater than the center frequency, or alternatively of 500 MHz bandwidth or more [3]. Two approaches for the implementation of a UWB communica- tion system are envisaged today by the industry: the carrierless impulse radio (IR-UWB) approach which consists of sending short duration impulses modulated in time, polarity or ampli- tude [2], [4], and the multiband approach, which consists in modulating several carriers by applying orthogonal frequency division multiplexing (OFDM). The latter is currently viewed as Manuscript received November 8, 2005; revised January 19, 2006. L. Smaïni, D. Hélal, C. Stoecklin, C. Devaucelle, R. Cattenoz, and N. Rinaldi are with STMicroelectronics, Advanced System Technology Laboratory, 1228 Geneva, Switzerland (e-mail: lydi.smaini@st.com; didier.helal@st.com). C. Tinella, L. Chabert, and D. Belot are with STMicroelectronics, Front-End Technology and Manufacturing, 38926 Crolles, France (e-mail: carlo.tinella@st.com). Digital Object Identifier 10.1109/JSSC.2006.873896 the best suited technology for very high data rate communica- tion applications, and is the main PHY candidate for the IEEE 802.15.3a standard. On the other hand, the main advantage of IR-UWB systems is that their implementation can lead to low complexity and low power architectures well suited for low data rate communication applications, plus short duration pulses en- able easier localization and tracking functionality due to their robustness against multipath fading. So far, UWB pulse generators have commonly been devel- oped for radar applications, but without the integration con- straint on a single chip. With the emergence of several very low-cost and low-power applications such as RFID (Radio Fre- quency IDentification) or sensor networks, the development of system-on-chip for this purpose becomes mandatory. Conse- quently, research is getting very active for achieving integra- tion of such UWB pulse generators in single-chip CMOS tech- nology. In [5] a CMOS solution has been proposed in the right direction, but its drawback is that it still needs an external RF choke inductor, which is not really suitable for complete integra- tion. On the other hand, [6] and [7] present single-chip CMOS architectures, but so far only simulation results are available. The impulse radio transmitter described in [8] has been man- ufactured in a 180 nm CMOS process. It uses a complex ar- chitecture with stringent timing accuracy constraints so as to create a pulse waveform compliant with the FCC indoor mask. Its average power consumption is 29.7 mW, for a supply voltage of 2.2 V, and the data rate is 36 Mb/s using binary phase shift keying (BPSK) modulation. In the present paper we propose a novel UWB pulse generator architecture which has been fully integrated on a single-chip in a CMOS 130-nm technology. It is simply based on edge combi- nation in order to form a “logical” pulse, which is sent through a bandpass filter, to obtain a correctly-shaped UWB pulse. The pulse shape can easily be changed by varying the delay between edges, or by varying the number of edges combined. Both pulse position modulation (2-PPM for two positions) and pulse po- larity modulation (BPSK modulation) can be used for data trans- mission, achieving data rate of 160 Mb/s. The pulse generator is a building block of a complete oper- ational IR-UWB transceiver system demonstrator [10], [11], as depicted in Fig. 1. Although the 3–10 GHz band can be exploited for UWB communications [3], for practical reasons this band is split in two subbands: 3–5 GHz and 6–10 GHz, in order to avoid difficult coexistence with wireless local area network (WLAN) services located in the 5–6 GHz band. Thus, the presented IR-UWB system demonstrator addresses the low band (3–5 GHz), like most of the first developments of UWB 0018-9200/$20.00 © 2006 IEEE