The Applications Of Transmission Line Theory In Switching Circuits

With the rapid development of technology in communications and power electronics, theeffects of the transmission line in these areas are apparent increasingly. So the research aboutthe transmission line has been paid much more attention in recent years, the articles referredto transmission line theory and applications emerge in large numbers in domestic and foreignjournals, but the research results about the analytical solution of transmission line equations isstill few. The reason is that the voltage or current of the transmission line is a superposition ofmultiple reflected waves and incident waves，and it is difficult to solve the equations.Meanwhile, the propagation velocity of the electrical signal on the transmission line is closeto the speed of light，so that it is very difficult for us to research the transmission line based onexperiments. Fortunately, with the function of the computer simulation softwares growingpowerful, it is convenient to use computer simulation to study the theory and application ofthe transmission line in switching circuits.The main content of this paper is divided into the following several parts:1） Deduce the transmission line equations based on Maxwell’s equations, expoundingthe transmission line equations from the "field theory"; Deduce transmission line equationbased on Kirchhoff’s law from the "road theory", building the transmission line model oflumped circuit.2） Get the analytical solution of the transmission line equations, and analyse thetransient response and steady-state response of the transmission line equations.3） Do time-domain simulation and S-parameter simulation about the transmission line,making theoretical analysis and interpretation to the simulation results, describing thecharacteristics of the transmission line by simulation.4） Study the applications of the transmission line in switching circuit. On the one hand，analyse the circuit signal on the transmission lines; The other hand, build the switching circuitmodel by transmission line model method.