A 5-GHz-band highly linear frequency tuning voltage-controlled oscillator (VCO) using 0.35 µm SiGe BiCMOS technology is presented. The highly linear VCO has a novel resonant circuit that includes two spiral inductors, p-n junction diode varactor units and a voltage-level- shift circuit. The fabricated VCO exhibits a VCO gain from 224 to 341 MHz/V, giving a Kvco ratio of 1.5, which is less than one-half of that of a conventional VCO. The measured phase noise is -116 dBc/Hz at 1 MHz offset at an oscillation frequency of 5.5 GHz. The tuning range is from 5.45 to 5.95 GHz. The dc current consumption is 3.4 mA at a supply voltage of 3.0 V.

A novel resonant circuit consisting of transformer-based switched variable inductors and switched accumulation MOS (AMOS) varactors is proposed to realize an ultrawide tuning range voltage-controlled-oscillator (VCO). The VCO IC is designed and fabricated using 0.11 µm CMOS technology and fully evaluated on-wafer. The VCO exhibits a frequency tuning range as high as 92.6% spanning from 1.20 GHz to 3.27 GHz at an operation voltage of 1.5 V. The measured phase noise of -120 dBc/Hz at 1 MHz offset from the 3.1 GHz carrier is obtained.

A fully integrated voltage controlled oscillator (VCO) MMIC for millimeter-wave applications has been designed and implemented in InGaP/GaAs heterojunction bipolar transistor (HBT) technology. To achieve a fully integrated VCO, a base-emitter diode is employed as the tuning varactor, and microstrip lines are employed for the transmission lines. The fabricated VCO MMIC chip size is 0.86 mm 1.34 mm and delivers an output power of 5.1 dBm at 28.7 GHz and a free-running phase noise of -118 dBc/Hz at 1 MHz offset. The dc current consumption is only 20 mA.