Ring-Based Triple-Push VCOs With Wide Continuous Tuning Ranges

This paper proposes a new ring-based triple-push voltage-controlled oscillator (VCO) architecture to achieve a wide tuning range and high operating frequencies. Two ring-based triple-push VCOs, one with a continuous frequency tuning range of 0.2–34 GHz, fabricated in 0.13- $\mu {\hbox{m}}$ CMOS, and the other with a range of 0.1–65.8 GHz, fabricated in 90-nm CMOS, are presented in this paper. These two VCOs demonstrate that the proposed VCO architecture can achieve a very wide continuous tuning range, up to millimeter-wave frequencies, without any device-switching operations. In addition to the wide tuning range, the chip area of the proposed VCO is very small, allowing integration into a phase-locked loop. The power consumptions of the 0.2–34- and 0.1–65.8-GHz VCOs are 2–70 mW from a 2-V supply voltage, and 1.2–26.4 mW from a 1.2-V supply voltage, respectively. The fundamental and second harmonic rejections are better than 15 dB for both VCOs.