In this paper, design consideration of the cascode configuration in low-noise amplifiers (LNA) using 0.13-μm CMOS technology is presented. Performance factors of LNAs such as signal power gain, noise factor, and power consumption are analytically expressed in device parameters from its small-signal equivalent circuit. The effect of the common-gate transistor in each performance factor is evaluated at the target frequency of 17-GHz ISM band. At this frequency, power gain and noise factor are degraded, which result from the common-gate transistor. Figure of merit of LNAs is also optimized.