Wide-Band Modeling On-Chip Spiral Inductors Using Frequency-Dependent Conformal ADI-FDTD Method

To analyze on-chip spiral inductors efficiently, an alternating direction implicit (ADI) finite difference time-domain (FDTD) method is proposed for general dispersive media. The time-domain recursive-convolution iteration equation can be used to calculate the Debye, cold Plasma, and Lorentz media in the same formula. A locally conformal technique, named medium parameters weighting method is proposed to modeling complex structure accurately. The spiral inductor integrated on the silicon substrate has been analyzed by using conformal ADI-FDTD method. And the simulation results are in agreement with the measured results. These data have been obtained over a wide frequency range from 0.1-20 GHz. The proposed method can easily be used as an accurate computer-aided design tool for radio-frequency integrated circuits.