A low-power, small area quadrature LC-VCO using miniature 3D solenoid shaped inductor

A low-power, small area quadrature 5GHz LC-VCO includes 20GHz oscillator and 1/4 divider has been fabricated using a miniature 3D solenoid shaped inductor in 90nm CMOS. Owing to a small area and a small magnetic energy of the 3D inductor, a chip area of 2597μm 2 which is 1/10 of the reported smallest LC-VCOs and 2.8mW power consumption including the divider have been achieved without degrading a figure of merit (FOM). The phase noise was −103dBc/Hz (@1MHz offset) and the phase error was ≪1.3°. The PLL using this LC-VCO achieved 1.2ps rms jitter with the chip area as small as that of ring oscillators. This small area LC-VCO is suitable for low-power, low-cost wireless transceivers and high speed communication systems.