A TRPC-UWB Transmitter Front-end Based on Wideband IQ Modulator in 0.13-µm CMOS Yiming Huo 1 , Xiaodai Dong 1 , Senior Member, IEEE, and Ping Lu 2 , Member, IEEE 1 ECE Department, University of Victoria, Victoria, CANADA 2 EIT Department, Lund University, Lund, SWEDEN E-mail: ymhuo@uvic.ca, xdong@ece.uvic.ca, Ping.Lu@eit.lth.se Abstract This paper presents a prototype 3.1-8.2 GHz UWB transmitter front-end based on a novel transmitted reference pulse cluster (TRPC) scheme in the 0.13-µm CMOS process. The transmitter front-end consists of wideband low noise active baluns, IQ modulator based on noise-cancellation mixers with high linearity, and differential to single-ended (D-to-S) converter. The measurements show that the worst-case carrier leakage suppression is 37 dBc, while the single sideband suppression (SSBS) is better than 29 dBc. Moreover, a power control range of 8 dB is achieved, and the maximum power consumption is 24.5 mA from a 1.2-V power supply. 1. Introduction Today’s wireless communication technolgoy has been experiencing unprecedented prosperity. The frequency spectrum resoruce, however becomes more precious. Therefore ulra-wideband (UWB) technology has attracted intensive attention due to its unlicensed frequency spectrum from 3.1 to 10.6 GHz regulated by FCC [1]. Over such wide frequency range, FCC also regulates that the emission power spectral density (PSD) should not exceed -41.3 dBm/MHz, so that UWB signals will not intefere with other spectra. TRPC is a recently proposed novel low data rate UWB communication technique which enables a low complexity, and efficient auto-correlation detector to be used for UWB transceivers [2]. It also voids the need of channel estimation for impulse radio UWB (IR-UWB). In this paper, a high performance radio frequency (RF) front-end for the novel TRPC-UWB transmitter with high performance (TX) is presented. The font-end is fabricated in the 0.13-µm CMOS process. Section 2 briefly introduces the specifications of a TRPC-UWB transmitter system, and then justifies the proposed architecture. Section 3 gives detailed descriptions of each function block design, and finally in Section 4 the experimental results from chip verification are given. 2. TRPC-UWB Transmitter Specifications and Architecture Direct-conversion topology is proved to be a reliable solution for most transceiver systems thanks to its higly pure output without undesired freuqnency products [3]. Active Balun Active Balun IQ Modulator Up-conversion Mixers D-to-S Converter BB_I+ BB_I- BB_Q+ BB_Q- RF_I+ RF_I- RF_Q+ RF_Q- RF Output Quadrature LOs LO_I+ LO_I+ LO_I+ LO_I+ BB_I BB_Q 3-8 GHz Driver Amp Matching Network Fig. 1. Block diagram of TRPC-UWB RF front-end As depicted in Fig. 1, pulse clusters which occupy a bandwidth from DC to more than 500 MHz are directly fed into the wideband active baluns respectively in I and Q paths. IQ modulator realizes the frequency up-conversion and its performance dominates the overall quality of the entire front-end. The proposed IQ modulator consists of two double-balanced mixers. Eventually, the up-converted differential RF signals are transformed to the single-ended signal through a D-to-S converter. At TRPC-UWB transmitter end, the maximum allowed in-band singal power is not only related to the FCC mask, but also to the date rate and the pulse cluster’s duty cycle. For simplicity, it is calculated as below: 10 , 1 -41.3 dBm/MHz + 10 log × pulse e pulse BW D          (1) where BW pulse is the bandwidth of one single pulse, D e,pulse stands for the equivelent duty cycle of the pulse cluster. Assuming under the 10 Mbps transmission mode, BW pulse is 500 MHz, and D e, pulse , is 15%, then ideally the maximum in-band singal power is -6.07 dBm as calculated. From this conclusion, a high conversion gain is not really required considering that the baseband’s input (from pulse generators) peak-to-peak amplitude is around hundreds of mV pp . However, DC offsets can lead to the growth of carrier leakage, which increases the error vector magnitude (EVM) and elevates the emission closer to the FCC mask. Thus, the port to port isolation becomes an important design parameter. In addition, nonlinearity and IQ mismatch need to be minimized. The noise figure (NF)