Abstract
This letter presents a wideband, low phase noise, quadrature voltage controlled oscillator (QVCO) implemented in 0.18 $\mu{\rm m}$ CMOS. In order to improve the phase noise while provide high efficient oscillation, the cooperation of a Class-C operation with a bulk-coupled structure are adopted into a PMOS-only VCO. With high fundamental current amplitude generated and the frequency offset of the QVCO alleviated, the phase noise is improved significantly. The measurement shows 2–8 dB phase noise improvement with a minimum value of $-124 ~{\rm dBc}/{\rm Hz}$ at 1 MHz offset. Wide tuning range of 22.6% is realized by four-bit switched-capacitor-array ranging from 5.6 to 6.9 GHz. The quadrature accuracy of the proposed QVCO is evaluated by the measured results of an image-rejection mixer (IR-mixer), which exhibits a peak image rejection ratio (IRR) of 40 dBc, indicating low amplitude and phase errors simultaneously.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
