Design considerations for extremely high-Q integrated inductors and their application in CMOS RF power amplifier

An extremely high-Q monolithic inductor (Q>2000) on silicon substrate was reported by Pehlke, Burstein and Chang (see Proceedings of the IEEE International Electron Device Meeting, pp. 63-6, 1997). The reported Q is 3 order of magnitude higher than a previously reported monolithic inductor. Such high quality factor may greatly improve the performance of monolithic RF circuits. Both 1-port (one terminal at ground) and 2-port (no terminal at ground) scattering parameters of the high-Q inductor were compared to examine any possible differences in device characteristics. A broadband physical model of the active inductor on silicon are presented to illustrate the improvement of quality factor. A design space with a range of gain and phase difference of current in the coils of the active inductor is reported. A typical application of the active inductor in CMOS RF power amplifier design is shown to illustrate the feasibility of applying the active inductor in RF circuits design.