The design of a 6.0-10.6 GHz UWB CMOS power amplifier (PA) for ultra-wideband (UWB) transmitters in TSMC 0.18-μm CMOS technology is presented. The UWB PA proposed in this paper employing a common gate (CG) amplifier as the input stage for wideband matching and the current-reused technique is used to save the power consumption and to enhance gain at the higher frequency. The shunt peaking inductors were used to improve gain flatness and to increase the total bandwidth of the circuit. The post-layout simulation results show that the input return loss (S11) was less than -8 dB, output return loss (S22) was less than -10 dBm, and average gain was approximately 11 dB over the frequencies ranges of interest. The input and output 1-dB compression point is -12 dBm and 0 dBm, respectively. Moreover, an excellent phase linearity property (group delay) of ±55.8 ps across the whole band was obtained with power consumption of 18 mW. The chip area is 0.77 mm 2.