High-performance 2-GHz CMOS LC VCO with high-Q embedded inductors using wiring metal layer in a package

This paper focuses on high-performance LC CMOS voltage-controlled oscillator (VCO) design at 2 GHz with high-Q inductors realized using wiring metal lines in advanced packages. Those inductors are used in the resonator of the VCO to achieve low phase noise, low power consumption, and a wide frequency tuning range. A fine-pitch ball-grid array (FBGA) package and a wafer-level package (WLP) are incorporated to realize the high-Q inductor. The Q-factors of inductors embedded in packages are compared with a Si on-chip inductor. The effects of the high Q-factor on the VCO performance are investigated. In addition, the dominant loss factor in an LC-tank is analyzed from the phase noise perspective. The VCOs using three different inductor technologies are presented. The performance of VCOs using the embedded inductor in a FBGA and a WLP is compared with that of a VCO using the on-chip inductor. The VCO design is optimized from the high-Q perspective to enhance performance. Through this optimization, less phase noise, lower power consumption, and a wider frequency tuning range are obtained simultaneously.