Tutorial: Circular Waveguide


 * Download the latest matlab file using gitweb: Circ_Waveguide.m
 * Simulation Time: ~ 7 min for a 2m long waveguide

We will cover in this tutorial:
 * setting up a cylindrical mesh
 * setup a mode profile excitation
 * create voltage and current probes using the mode profile
 * calculate the waveguide impedance and S-Parameter

First Steps

 * Install and verify your openEMS installation: Tutorial: First Steps
 * You may have a look at the rectangular waveguide example which is mostly identical to this tutorial

Matlab Simulation Script

 * Start the script within an empty environment:


 * Setup the simulation parameters


 * Set cylindrical FDTD parameters and the Gaussian excitation pulse


 * Define the cylindrical homogeneous mesh


 * Apply waveguide ports


 * Define a dump box using the HDF5 file format


 * Save & Run the simulation

Post-Processing

 * Calculate s-parameters and waveguide impedance


 * Plot S-Parameters


 * Compare analytic and numerical wave-impedance

Modifications

 * Try different/multiple modes for excitation/detection
 * Add an unsymmetrical dielectric material load to see a mode-conversion (multiple mode detection necessary)
 * Try adding a periodic dielectric material to see a frequency selective reflection (Bragg reflections)