On Maxwellian circuit in time domain

Abstract

Maxwellian Circuits is deduced from Maxwell¡¦s equation by professor K. K. Mei. With the theory of existence and uniqueness, the Maxwellian Circuits is invariant of termination conditions of thin wire structures and transmission lines. Through a heavy study, we found the broadband property of the circuit parameters of the Maxwellian Circuits in microstrip non-uniform transmission lines below 25 GHz. For more complicated cases, two important models that describe the connection and parallel coupling of multi-lines are also founded to be very broadband below 25 GHz. From the Maxwellian Circuits, the topic of this thesis is to develop a fast and little memory occupied time-domain simulation method for application in microstrip circuits, from basic uniform transmission line to complicated circuit such as low-pass filter, band-stop filter, branch and band-pass filter. Method of moment is used to extract the broadband circuit parameters of Maxwellian Circuits. And from the principle of the Finite-Difference Time-Domain method, using leapfrog in space and time, Mur¡¦s 1st order ABCs and time-domain Maxwellian Circuits, the new time-domain method we named ¡§On-line FDTD¡¨ is developed. This method is suitable to passive one-layer microstrip thin line structures with appropriate accuracy, little computer memory occupied and extreme fast simulation speed compared with 3-D FDTD method. And it has been preparatorily applied in the fields such as EMC and CAD and those experiments show its vitality. As the accuracy is concerned, the method cannot be as accurate as 3-D FDTD and MoM, but the accuracy of this method is sufficient to estimate the broadband performance and transient time-domain signal in almost real time.