The comparison and combination of CMOS inductor Q-enhancement techniques

Much emphasis and blame has been placed on integrated silicon inductors and their poor Q values, leading to degradation in circuit performance, especially at RF and microwave frequencies. This is no more evident than in WLAN applications at 5.25 GHz where poor Q values can induce increased noise figure, power consumption and linearity deterioration. This paper will present a concise comparison of non-invasive Q-enhancement techniques using patterned ground shields, stacked metal, thick copper and differential inductors. A differential stacked metal inductor with patterned ground shield will also be demonstrated for its effectiveness.