Performance Analysis of RF Spiral Inductor with Gradually Changed Metal Width and Space

To decrease the metal losses of RF spiral inductor,a novel layout structure with gradually reduced metal line width and space from outside to inside is presented.This gradual changed inductor has less eddy-current effect than the conventional inductor of fixed metal width and space.So the series resistance can be reduced and the quality (Q) factor of the inductor relating to metal losses is increased.The obtained experimental results corroborate the validity of the proposed method.For a 6nH inductor on high-resistivity silicon at 2.46GHz,Q factor of 14.25 is 11.3% higher than the conventional inductor with the same layout size.This inductor can be integrated with radio frequency integrated circuits to gain better performance in RF front end of a wireless communication system.