This manuscript describe optimization of LNA using PSO algorithms. The proposed LNA consist of two stage cascading. In the first stage current reused technique has been used using complementary MOS. Both the MOS use the common biasing current, henceforth saving a lot of power. While second stage is the cascading of two NMOS transistors, to increase the overall gain. Since traditional method of impedance matching is not sufficient to reduce the Noise Figure(NF). Therefore, an approach aiming to minimize high band noise has been used at the cost of increase in NF minimum. All the passive elements and aspect ratio are optimized through PSO in which objective function consist of NF and voltage gain term. Number of iterations used in PSO algorithm is 1500. LNA is simulated in 45 nm CMOS Technology for a wide range of frequency from 1GHz to 20GHz. Simulation show minimum NF of 1.89 Db, power gain(S21) and input reflection coefficient(S11) 16.8dB and − 19.2dB. Process corner simulation for robust ness of LNA has been done and depicted ten percent variation around the typical value of LNA. The power consumption of 32 mW and chip area order of 2.2mm × 1.6mm with core area is 650 µm in layout design.