Low power design of CMOS 5-GHz voltage-controlled oscillator from narrowband to wideband with switching capacitor module

In this study, we demonstrated low power and low phase noise of the complementary cross-coupled voltage-controlled oscillators (VCOs). Two chips are implemented by TSMC standard 0.18-mum complementary metal-oxide semiconductor (CMOS) process. The first one that employed a memory reduction tail transistor technique is operated from 5.17 to 5.85 GHz at a supply voltage of 1.2 V whereas its tuning range is 12.3%. The power consumption is 1.8 mW whereas the measured phase noise is -126.6 dBc/Hz at 1-MHz frequency offset from 5.17 GHz. The other employed switching capacitor modules to achieve wide tuning range and minimise phase noise, it operated from 3.64 to 5.37 GHz with 38% tuning range. The power consumption is 13.7 mW by a 1.8 V supply voltage and the measured phase noise in all tuning ranges is less than -122 dBc/Hz at 1-MHz frequency offset.