Design of CMOS voltage controlled oscillators using package inductor

This paper presents three different types of CMOS Voltage-Controlled-Oscillators (VCO) with the integration of embedded inductors in a multi-layer package. A high quality (Q) inductor, pertinent to creating an efficient VCO, is easily made with a thick wiring line in a multi-layer package, The embedded inductors are designed with two different packaging technologies. One is a Fine Pitch Ball Grid Array Packaging (FBGA) technology and the other is a Wafer Level Packaging (WLP) technology. The FBGA inductor showed a Q-factor about 60 at the frequency of 2GHz and that of a WLP inductor was about 25 while at 2GHz. The performances of VCOs using embedded inductors were compared with the control, a VCO designed with conventional on-chip inductors. The use of FBGA and WLP created numerous advantages. The Total Figure-Of-Merit (FOM) was enhanced due to not only reduced phase-noises, but also to improved efficiency and tuning range.