I have a very narrow band filter at 915MHz with a 26MHz band pass. Its rejection at 930MHz is more than 30dB!!!!. I think it is a dielectric resonator filter but I am not sure about it. The photo is attached. Please help me to find the type of this filter and the part number of resonator.
These are Coaxial Resonators and they can be inqiured from-for instance- http://www.trans-techinc.com/index.asp
There are other Advanced Dielectric Materials manufacturer, search google.
the way that board is laid out is NOT the way to do it. You want the resonator heads to all be at one side, close together. Too much line length between resonators.