The left figure shows an animation of a wave on a transmission line. The right figure shows the terminal voltages after the simulation has finished.
At the left side is a generator with series resistance Rgen, generating a signal with amplitude 1.0. A sine generator has a configurable period, a pulse generator has configurable period and rise time. At the right side is a load with resistance Rload or capacitance Cload.
Fill in the different parameters, and click the button to start an animation of a wave going back and forth between generator and load.
The simulation time step is exactly the Courant limit. It depends only on parameters l, v, and nx, not on load capacitance or generator period. Increase the number of segments if the simulation time step is too small compared to the time constant of the load, Z0 x Cload, or the generator period and rise time.
| Parameter | Value | Description |
|---|---|---|
| l | {{ lUnit.toFixed(1) }} µH/m | Inductance per unit length |
| c | {{ cUnit.toFixed(1) }} nF/m | Capacitance per unit length |
| Tprop | {{ tProp.toFixed(2) }} ns | Propagation time of transmission line |
| Tstep | {{ tStep.toFixed(0) }} ps | Time step for simulation (Courant limit) |
| Nstep | {{ nStep.toFixed(0) }} | No of steps in simulation |
| ρgen | {{ rhoGen.toFixed(2) }} | Reflection coefficient at generator |
| ρload | {{ rhoLoad.toFixed(2) }} | Reflection coefficient at load |
This simulation uses the finite-difference time-domain method (FDTD). References:
Source code: https://github.com/renaatd/transmission-line