Through the wide need of wireless communication systems, the transmission data quota is continuously promoted. For the carrier frequency 5.2GHz, the ISM (Industrial, Scientific and Medical) band specification for the IEEE 802.11a in wireless LAN standard was adopted. In the past, the 802.11b proposed a wide range of applications with 2.4GHz carrier frequency. Due to the need of higher transmission rate, 802.11b with 11Mbit/s is obviously inferior to 802.11a as an amendment to the IEEE 802.11 specification that added a higher data rate of up to 54 Mbit/s using the 5.2GHz band. In wireless communication systems, the LNA plays an important role as the first stage amplification in receiver such as signal amplification and noise immunity affecting the post amplifier.