3.1–10.6 GHz high linearity, excellent gain flatness CMOS power amplifier for UWB applications using stagger tuning technique

In this paper, an Ultra-Wide-Band (UWB) RF power amplifier (PA) which provides some great features such as high and flat gain, low power, small group delay variation and a greater stability across the entire spectrum from 3.1GHz to 10.6 GHz is proposed. The UWB PA that it is implemented in 0.18μm CMOS technology employs stagger tuning technique which incorporates two stage amplifier connected in cascode configuration to establish a wider bandwidth. Low power consumption is decreased by employing the current-reuse topology and high linearity is achieved by using the self-biased circuit. The simulation results show that the proposed UWB PA has an excellent gain flatness of 18±0.2 dB and flat and low noise figure (NF) of 2.63±0.29 over the frequency band of interest. The PA design realizes a good phase linearity property (group-delay-variation) of ±25 ps over the whole band, so it is unconditionally stable. An input return loss (S11) inferior to -10dB, output return loss (S22) smaller than -8.4dB and an excellent reverse isolation S12 less than -30 dB. The input third-order intermodulation point (IIP3) is 2.25 dBm at 7 GHz to ensure more linearity.