An analytic input matching technique for low noise amplifiers (LNA) has been presented. This method has been developed to design of cascode LNA for millimeter wave applications in modern CMOS technologies. Unlike the conventional analytic matching [1], the accurate transistor model used in our analysis, leads to acceptable accuracy in this frequency range. The analysis results have been used in design of a 30GHz LNA for STMicroelectronics 90nm digital CMOS process. Simulation in foundry design kit shows excellent accuracy of proposed method in comparison with the conventional method. The designed LNA have 10dB power gain with 5mW DC power consumption.