Terminator3
Advanced Member level 3
Recently i found out that such problem still exists. I searched this board and found this old thread: https://www.edaboard.com/threads/49614/ , that suggests to
and also4. Use a more expensive fabrication method that has lower etching tolerances or use thinner metal (which will decrease the chemical etching time and undercutting) and then plate the thickness up.
Any news in this area? I read about ring resonators are good for overetching, because only it's inner and outer radius is affected, but mean radius remains at designed frequency lambda. The other way is to make filter for a little higher frequency and always tune it by adding high dielectric material on top, or some conductive paint to make lambda a little longer. If any cheap proccess available to make tighten tolerances, i would be happy to hear.3. Try some other filter topology that might be less sensitive to the dimensions. I cannot think of any, but other board members may know of them.