A Highly Linear LNA with Noise Cancellation for 5.8-10.6 GHz UWB Receivers

This paper presents a new ultra-wideband LNA which employs the complementary derivative superposition method in noise cancellation structure. A pMOS transistor in weak inversion region is utilized for simultaneous secondand third-order distortion cancellation. Source-degeneration technique and two shunt inductors are added to improve the performance at high frequencies. The degeneration inductor resonates at fT/2 and realizes a new input matching technique that widens the bandwidth with decreasing it’s quality factor and input capacitance, while flattens the input resistance and also improves the 1dB Compression Point. The shunt inductors resonate at the center frequency of the band and improve the effective bandwidth of noise/distortion cancellation technique. This LNA has been designed in a 0.18 μm CMOS process and consumes 8.3 mA from 1.8 V power supply. The chip area is 0.55 mm. The noise figure and voltage gain are 4.48-5.18 dB and 13 dB, respectively. S11 is lower than -13.5 dB over 5.8–10.6 GHz and IIP3 is 14.5– 17.5 dBm, IIP2 is 14–15.5 dBm. This technique improves IIP3 more than 9 dB.