A 0.18 μm CMOS low power ring VCO with 1 GHz tuning range for 3-5 GHz FM-UWB applications

A 0.18 mu m CMOS low power ring VCO for 3-5 GHz FM-UWB system applications is presented. In order to achieve a 1 GHz ultra-wide tuning range while retaining a low power consumption the conventional ring configuration is modified. A detailed analysis of the proposed VCO configuration is presented in terms of oscillating frequency, control performance and phase noise performance. During the design phase several tradeoffs were made between power consumption, phase noise and tuning range. Measurement shows that the proposed VCO configuration can provide a tuning range of 1.4 GHZ at 2.7-4.1 GHz while offering a -70dBc/Hz phase noise level at a 1 MHz frequency offset. The VCO furthermore shows a good tuning linearity. In total the circuit consumes 9.5 mW.