Investigation of current crowding effect on spiral inductors

High-Q inductors are the important elements for RF circuit design, especially in the cellular and PCS bands, where they are difficult to be realized. We discuss and explain the current crowding effect, which degrades the Q of the spiral inductor, as the number of turns increases. Both the method of moment (MOM) and the finite-difference time-domain (FDTD) technique are applied to this analysis.