A low phase noise LC-VCO with a high-Q inductor fabricated by wafer level package technology

This paper presents a CMOS voltage controlled oscillator (VCO) with a high-Q inductor fabricated by using a commercial wafer-level-package (WLP) technology. A new topology suitable for CMOS VCOs with high-Q WLP inductors is proposed. Measured Q of a WLP inductor is 40 in differential mode at around 1.9 GHz. A phase noise is −134.4 dBc/Hz at a 1MHz offset for 1.9GHz carrier frequency, and a FoM is −193 dBc/Hz. The VCO with the WLP inductor improves a phase noise of 6.4 dB as compared to VCOs with conventional on-chip inductors.