Optimization of LC-VCO tuning range under different inductor/varactor losses limitations

This paper presents the main challenges in the design of wide tuning range LC voltage controlled oscillators (LC-VCOs) in CMOS technologies. Design trade-offs such as tank losses, phase noise, and power consumption are discussed and analyzed. A VCO that has a wide tuning range that covers frequencies from 5.5 GHz to 10.2 GHz was designed and fabricated in a 65 nm CMOS process. The worst case measured phase noise is -83 dBc/Hz at 1 MHz frequency offset from the carrier. The design occupies 0.125 mm² silicon area, and dissipates 11 mW (excluding the buffers).