A highly attenuative CMOS LNA at 5-6 GHz using negative G_M circuit for UWB applications

This paper presents a UWB low noise amplifier (LNA) for 3.1-10.6 GHz applications, with an excellent attenuation at 5-6 GHz for rejecting the wireless local area network (WLAN) interference. A method of canceling the on-chip inductive resistance has been employed in this work to make the inductor an extremely low loss inductor with a very high quality factor. The fully integrated UWB LNA is designed in the CMOS 0.18 μm Taiwan Semiconductor Manufacturing Company (TSMC) technology. Measurement results show that the LNA achieves attenuation of up to 39 dB at 5.4 GHz, while the 1 dB power gain is 10 dB. The measured return losses (S₁₁ and S₂₂) are better than -7.4 dB while the noise figure is 5-6.1 dB in the range of operation. The measured input P_1dB and IIP₃ measured at 6.5 GHz are -12.2 and 2 dBm, respectively. The designed LNA occupies an area of 1.105 × 0.68 mm².