A while back, one of the local microwavers was looking for an up to date version of the WGFIL program by Dennis Sweeney WA4LPR. This, and INTRFIL, were available in various forms across the net, including old .com binaries, and in source form (Pascal), which compiled and ran perfectly with the Free Pascal Compiler (fpc) on Linux.
I contacted the author and asked about putting the source into a GitHub repo so it would be easy to find in the future and he was happy for me to do that. The code is licensed under the GPL.
So, here is the repo: https://github.com/xjamesmorris/wa4lpr_filters
Included alongside the sources are papers on each app:
- WGFIL v1-3 Waveguide Band-Pass Filter Program, Dennis Sweeney WA4LPR, April 2021 (Revised 02/04/2023). (pdf)
- Design and Construction of Round Rod Interdigitated Filters, Dennis Sweeney WA4LPR, August 2021 (Revised 01/09/2022). (pdf)
There are also some excellent papers on microwave filters and using WGFIL at Paul Wade W1GHZ’s site: QEX articles by W1GHZ.
Many thanks to Dennis for making the code available! It has proven useful to many folks over the years.