A 5-GHz low phase noise CMOS VCO for IEEE 802.11a WLAN

A fully integrated 5.3 GHz low phase noise CMOS VCO for WLAN application was presented and simulated. Based on the analysis of the phase noise theory, a p-tail complementary cross-coupled pairs structure was adopted, and a high performance inductor and the AMOS varactor were designed. Through the simulation in 0.18µm CMOS TSMC technology, the phase noise achieved is −120 dBc/Hz at 1MHz offset from the carrier frequency. The supply voltage is 1.8 V, and the power dissipation is 5.2 mW, while the tuning range is about 18%. The performance of the proposed VCO well achieves the requirements of the IEEE 802.11a standard.