A 5–5.47GHz LC-VCO using varactor configuration in 0.18um CMOS technology

In this work we have presented two varactor configurations for implementing LC-VCO, is demonstrating an improved phase noise performance. The LC-VCO is implemented in 0.18μm CMOS technology. The varactor configurations used in this work are I MOS and DSB, their schematic is simulated and analyzed in cadence virtuoso tool. We emphasis on the importance of VCO operating in GHz range and its integration in monolithic IC. The operating frequencies used for I MOS and DSB are 5-5.47 GHz, the phase noise obtained @ 1MHz offset -115dBc/Hz and -100.5dBc/Hz and FOM are -211.98 and -198.26 respectively. VCO design techniques and design trade-offs are highlights in this work.