Analysis and design of ultra‐wideband low noise amplifier using complementary structure with series inductive peaking technique and shunt feedback

Summary In this paper, an ultra‐wideband low noise amplifier (LNA) is presented using 0.18‐μm RF CMOS technology. A complementary structure with series inductive peaking technique is introduced by using two inductor‐loops to achieve flat gain. In the first and third stages, two complementary structures are utilized to achieve a high and flat gain, a wideband input impedance matching and a low noise figure. In addition, a shunt feedback is utilized to increase input impedance matching and stability. In the second stage, a common source structure is used as interstage, which increases the −3 dB bandwidth. The designed LNA presents a high and flat gain of 15.6–16.5 dB, an excellent input return loss better than −11 dB and a good NF of 2.2–3 dB in the frequency range of 3.1–10.6 GHz. Also, the proposed structure consumes 6.8 mW from a 0.8‐V supply voltage and has an IIP3 of −4 dBm at 6.5 GHz. The proposed structure only occupies 0.59 mm 2 .