AADE Filter Design is FREE for download

Version 4.0 added two new types of SSB crystal ladder filters described in an article " Modern Network Theory Design of Single-Sideband Crystal Ladder Filters, M. Dishal, Proceedings of the IEEE December 1963" 

Version 4.11 adds the ability to store up to six sets of crystal parameters from your collection of crystals.

That way you don't have to re-enter them everytime you want to design a crystal filter.

Adds a little more to the crystal filter tutorial in the HELP file.

4.2 adds the ability for odd order Elliptic filters to have user specified input / output impedances that are different.

4.3 is an update to the HELP file.  update is optional.

4.4 adds a "troubleshooting installation" item to the HELP menu  No change to program so if yours works you don't need this.

Since nobody seems to read the web troubleshooting information I have put it in the program as well.

TROUBLESHOOTING those rare problems

For Windows XP, Some functions of Filter Design may not work when the program is launched from the START menu or desktop icon. 

If so, delete the desktop icon and remove the program from the start menu.
Browse to the program, C:\program files\filter\filter.exe, right click on it, create a shortcut and put it on the desk top. 
Also you can right click on the desktop shortcut and PIN it to the start menu.
HLink is no longer required for new downloads so this problem will not exist.
If, after installing filter.exe, you get the error message
"componet hlink.ocx or one of this dependencies not correctly registered: a file is missing or invalid"
If that does not fix it then goto START then RUN and manually register it.
HLInk_fix.jpg (9877 bytes)
if the file is not found then
download HLink.zip  unzip it into C:\window\system32 
After that you should see a message that the file was registered successfully.
You try to open the help file and notice a weird error message Cannot open the file:Mk:@MSITStore:\Filter\fdhelp.chm.

The problem is caused by the file hhctrl.ocx located in your System32 folder  and most likely has been overwritten by an application with an incompatible version.
download a working version : hhctrl.zip
When you have it on your computer, just unzip it into your c:\windows\system32\    folder  and overwrite the old version.
Then, go to your start Menu and select Run and manually register it.:

regsvr32 c:\windows\system32\hhctrl.ocx
After that you should see a message that the file was registered successfully.

Related links:


This problem may appear when installing in Windows VISTA.
If, after installing filter.exe, you get an error message regarding the registration of Comdlg32.ocx
first check to make sure comdlg32.ocx is in the C:\WINDOWS\system32\ directory.
go to START / RUN and manually register it.
comdlg_fix.jpg (9233 bytes)
After that you should see a message that the file was registered successfully.

version.jpg (9306 bytes)

If your version number is less than the current version then install fdupdate.exe (12.1Mbytes)

AADE Filter Design is now FREEWARE.

My apologies to those who paid for it earlier.

Click here to view some of the added features

Download and Installation Instructions.

Download fdinstall.exe (14.3Mbytes) which, with IE shows the following, (Netscape has a similar function)

file download.jpg (11351 bytes)

and select to either open.jpg (1046 bytes) which will download the file and then run it to install.


select to save.jpg (1386 bytes) which will save the file to your specified location and then you should RUN the fdinstall.exe to install.

Program works best at 1024 X 768 resolution or greater, its nice at 800 X 600, barely usable at 640 X 480

AADE Filter Design version 4.x is greatly enhanced over the previous version.

It offers several new features.


It designs TOROID and AIRWOUND inductors.

It designs resistive ATTENUATORS.

It has several powerful TRANSFORMATIONS
that enable you to modify component values to make the filter easier to build and align.

It also has a giant HELP system
which is far more than just how to use the program. It is a tutorial in filter design and analysis.