As some of you have generously pointed out there is a bug in Couplings Designer 1.3 that was introduced with the iOS 7.1 release a couple of weeks ago. The bug introduces a crash whenever one is performing any of the following actions:
- Crashes when synthesizing a new design. A temporary solution is to return back to the newly created design which will now work normally since this bug only appears for newly created designs.
- Crash on design export (via email). Also seems to corrupt the selected design’s data, use this feature with caution.
Please comment below if you are experiencing issues with the app! I will update the software as soon as possible to support iOS 7 better, it will most likely be an iOS 7-only release since Apple has introduced a lot of changes to the SDK since the release of iOS 5 in 2011. The plan is to have these bugs resolved in 1-2 weeks time.
Thank you for your understanding and support, I am sorry for the inconvenience!
Edit (April 10): update 1.4 has been submitted to Apple for approval, which usually takes a week until it ends up in the AppStore. In addition to the bug fixes there are a couple of new features added and a fresh new interface.
Edit: Couplings Designer 1.4 now available on the AppStore.
An aluminum coaxial re-entrant resonator is designed for high Q to meet specifications on insertion loss. High rejection is achieved with a symmetrical pair of transmission zeros implemented using an electric probe. The filter is implemented with the well known folded topology which is fairly insensitive to manufacturing tolerances. Port tuning is introduced which cuts simulation time and makes the connection to the synthesized coupling matrix transparent.
In this tutorial we will learn how to synthesize and implement a chebyshev response with a combline cavity topology using Couplings Designer. Couplings are extracted and linked to physical dimensions and then combined to realize the final filter layout. It will be shown that unintended couplings may distort the passband and stopband performance. These coupling are analyzed by Couplings Designer with a new coupling matrix that takes them into account and the final physical dimensions are tuned to reflect the change, finally retreiving the chebyshev response.
Currently looking for beta testers of a new filter synthesis tool, similar to Couplings Designer, for windows. I will select a number of testers that will be rewarded with the end product when released. You need to be familiar with coupling matrices and have experience designing filters using them, otherwise your feedback will not be as helpful. Let me know which version of windows you are running too. Sounds like an interesting deal? Write a comment or send me an email and I’ll come back to you.
Learn how to turn your synthesized coupling matrix into lumped elements for low frequency applications where waveguide and planar implementations wouldn’t make sense. It is also interesting reading for those doing miniature filters on thin film or MMIC at higher frequencies.