Wide Tuning Range X-Band LC-VCO Designed in 90 nm CMOS Technology

This paper presents a wide tuning range LC-VCO with additional power down and differential-to-single circuits designed in 90 nm CMOS technology. Designed LC-VCO generates signal in widely used X-band frequency range. Post-layout simulated frequency is $7.97-11.53 \mathrm{GHz}$ reaching 36.44% frequency tuning range. Achieved simulated phase noise of ${- 1 1 1. 0 8 ~ d B c / H z}$ at 1 MHz offset from 7.976 GHz carrier frequency. The proposed VCO achieves FOM<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</inf> of -183.07 dBc/Hz.