A Wide-Tuning Range Low Phase Noise LC-VCO with a High Q Switched Capacitor Array

A fully-integrated inductance-capacitance (LC) voltage-controlled oscillator (VCO) with a wide tuning range and low phase noise was designed and demonstrated in 130 nm CMOS technology process. To achieve a higher quality factor (Q) value, a proposed switched capacitor array (SCA) combining 4-bit switched capacitors with large capacitance and 3-bit switched capacitors with small capacitance is adopted, which occupies a small area at the same time. In addition, a varactor array and a tail resistor array are used to provide flexibly dynamic VCO gain adjustment and power consumption adjustment, separately. The measurement shows a continuous tuning range of 48% from 1.9 to 3.1 GHz and consumes 8 mW of DC power from a 1.2 V supply voltage (excluding buffers). Furthermore, this design displays the phase noise of 125.63 dBc/Hz at 1 MHz offset from its 2.5 GHz oscillation frequency. The proposed VCO's measured figure-of-mer it including the tuning range (FoM ������) is-197.39 dBc/Hz at a carrier frequency of 2.5 GHz, which demonstrates the potential of the proposed VCO for application in integrated circuits.