An Excellent Phase-Linearity 3.1-10.6 GHz CMOS UWB LNA Using Standard 0.18 μm CMOS Technology Chang-Zhi Chen, Jen-How Lee, Chi-Chen Chen, and Yo-Sheng Lin Department of Electrical Engineering, National Chi Nan University, Puli, Taiwan, R.O.C. Tel: 886-4-92912198, Fax: 886-4-92917810, Email : stephenlin@ncnu.edu.tw Abstract- A 3.1-10.6 GHz ultra-wideband low-noise amplifier (UWB LNA) with excellent phase linearity property (group-delay-variation is only ±17.4 ps across the whole band) using standard 0.18 μm CMOS technology is reported. To achieve high and flat gain and small group-delay-variation at the same time, the inductive peaking technique is adopted in the output stage for bandwidth enhancement. The UWB LNA dissipates 22.7 mW power and achieves input return loss (S 11 ) of -9.7 ~ -19.9 dB, output return loss (S 22 ) of -8.4 ~ -22.5 dB, flat forward gain (S 21 ) of 11.4 ± 0.4 dB, reverse isolation (S 12 ) of - 40 ~ -48 dB, and noise figure (NF) of 4.12 ~ 5.16 dB over the 3.1-10.6 GHz band of interest. Good 1-dB compression point (P 1dB ) of -7.86 dBm and input third-order inter-modulation point (IIP3) of 0.72 dBm are achieved at 6.4 GHz. The chip area is only 681 μm × 657 μm excluding the test pads. Index Terms- CMOS, phase linearity, ultra-wideband (UWB), low-noise amplifier, noise figure I. INTRODUCTION Recently, ultra-wideband (UWB) systems have attracted a lot of attention because they are capable of high data-rate transmission with low power consumption. UWB LNA is a critical block in UWB receiver front-end design. To amplify the small radio-signals received from the whole UWB band (3.1-10.6 GHz) with a good signal-to-noise ratio property, high and flat power gain S 21 , good input impedance matching (i.e. low input return loss S 11 ), and good noise figure (NF) performances across the whole UWB band are required. Several UWB LNAs have been reported in recent works [1]- [8]. For an UWB LNA designed for OFDM systems [1], power linearity must meet a stringent requirement for the purpose of suppressing adjacent channel interferences, while this requirement is more relaxed in UWB pulse-radio systems [2]. In the latter, good phase linearity is required instead in order to keep the shape of the pulse when receiving RF-signals from an antenna. To demonstrate that good power and phase linearity performances can be achieved simultaneously for a CMOS UWB LNA, in this work, we demonstrates a high- performance 0.18 μm CMOS UWB LNA with good power and phase linearity performances, which is suitable for both OFDM and UWB pulse-radio system applications. Fig. 1 (a) Complete schematic, and (b) die photo of the 3.1- 10.6 GHz CMOS UWB LNA. RF IN RF OUT V G2 V D2 V D3 V G3 L G1 L D3 L G3 L D2 L S1 (a) (b) RF IN V D2 = 1.9 V ID2 = 8.21 mA VG3 = 0.745 V L G1 = 771.7 pH R F1 =192.9 Ohm R D2 = 70.2 Ohm LD2 = 1.912 nH C= 1.38pF R F3 = 230.7 Ohm CF3 = 159.2 fF Lg3= 1.28nH R G3 = 1999.7 Ohm VG2 = 1.49 V RG2 = 1999.7 Ohm CB1 = 4.76 pF 228/0.18 LS1 = 203.1 pH 228/0.18 RF OUT VD3 = 1 V I D3 = 7.12 mA L D3 = 2.47 nH 140/0.18 Proceedings of Asia-Pacific Microwave Conference 2007 1-4244-0749-4/07/$20.00 @2007 IEEE.