Catalog of Baluns & Ununs Equivalent Circuits

When we simulate antennas, we model baluns and ununs as ideal transformers: their impedance transformation ratio is exactly equal to 1:N (or N:1) for any frequency and any load, and they do not introduce any power loss nor any phase shift. Such approach sometimes leads to noticeable disagreements between the simulation results and the real-world measurement results. I have experienced it myself.

So, what should we do? We should use a more complex equivalent circuit in which an ideal transformer is just one of the several components used.

I measured a number of baluns and ununs and calculated their equivalent circuits. I gathered this information in an Excel workbook, which you can freely download. You will need MS Excel version 2007 or later to open the catalog because it uses macros and has some code written in Visual Basic. Big thanks to Dan, AC6LA, for enhancing my simple workbook. The catalog user manual explains in detail how to add a balun/unun model to your AutoEZ antenna project file.

I keep adding new devices when I have time to construct and measure them. If the other hams contribute, this catalog will grow faster. How can you contribute? I explained it in the user manual that is included in the downloadable zip file.

Click here to download the latest version of the catalog and its user manual.