Dielectric-loaded waveguide

Updated November 20, 2007

Click here to go to our main page on waveguide

Click here to go to our main page on waveguide loss

New for December 2007! Rectangular waveguide is most often filled with air, sometimes pressurized in high-power application. Why would you want to fill it with a dielectric? One reason is to shrink the dimensions. Sometimes you might want to load the waveguide with a ferrite material, perhaps to make a circulator.

While we're waiting for this page to emerge from the fog, go to the download area and get the latest waveguide loss spreadsheet, it now includes the ability to account for dielectric loading!

The waveguide can be partially loaded, or completely loaded with a dielectric material. For now, the analysis on this page only considers the fully loaded case. It's easier to analyze, OK?

For reference, we used Pozar's Microwave Engineering, which you can find on our book page. Launch from there into Amazon and order yourself a copy.

Let's start with the easiest calculation, the wave number at cutoff. Let's also concentrate on the TE10 mode, which is what 99.99% of time all we care about in rectangular waveguide.

Now let's consider the wavenumber, k. In waveguide the wavenumber is reduced below what it would be for TEM media, especially as you get close to cut-off:

Here's a new page on wave number.

More to come!