Research Of Multi-Conductor Transmission Lines Based On The Finite Difference Time Domain

With the growth of economic and technology, electronic technology is gradually full of people’s daily life and study. As people have more and more requirements to the electronic equipment, the circuit system is becoming smaller and high precision gradually. Because of the improvement of the clock frequency, the crosstalk and distortion on the transmission line is getting worse. The transmission line’s effect of the signal linked line to the signal performance must be considered, so the research of the signal’s propagation performance on the transmission line has become the main problem of the EMC design.First, the multi-conductor transmission line equations, phenomenon of signal crosstalk and reflection on the transmission line, and the calculation principles of the Finite-Difference-Time-Domain (FDTD) method is discussed in this paper. Three different types of the transmission line is modeled, the transient response’s iterative differential equations is derived using FDTD method, and each type of the transmission line’s transient response by simulation is analized. Then, the transient response algorithm of the unequal-length non-uniform’s transmission line with termination of nonlinear load is proposed based on FDTD method. The accuracy of the algorithm is demonstrated, the transmission line’s transient response with termination nonlinear load under the different excitations is analized based on this algorithm, and the transmission performance according to the transient response curves is discussed. Finally, the method to avoid the shake of waveform and to keep the signal integrity is proposed by researching the performance of transient response curves changing with the parameters, which provide a theoretical basis for the design of the transmission line.