Efficient synthesis technique of time-domain models for interconnects having 3-D structures based on FDTD method

This paper describes a novel method to simulate transient responses of interconnects having 3-dimensional structure. First, the impulse responses between any pair of terminals of lines are obtained by the finite-difference time-domain (FDTD) method. In this calculation, the characteristic impedance of the interconnect is imposed at every terminal in order to converge quickly the transient waveforms. Next, the frequency responses are obtained by the Fourier transform of these transient waveforms. Then, the time-domain models are synthesized from the frequency responses by using the least square approximation and the complex frequency hopping technique. Finally, with this model, the transient responses are rapidly simulated by the conventional circuit simulators. In conclusion the validity of this method is verified by comparison with the time-consuming FDTD simulation