Epoxy material for MWS ?
You should look for material properties in the specs of your PCB supplier. (permittivity, permeability, conductivity, dispersion, substrate loss ...)
Hi Irfan and All
I may sound stupid but what is MWS......Microwave Studio?
DeeJay
There are so many types of epoxy. You can ask the manufacturer. But usually only data for low frequency is given. If you are interested in high frequency, you make test structure to characterize it (e.g. CPW).
Diel Const of FR4 can vary from 4.3-4.8 from batch to batch. And is temperature sensitive as well. Loss Tangent can vary between 0.018-0.030, depending on number of layers, board thickness, etc.
Using FR4 as substrate for microwave circuits, requires tolerance analyses of the FR4 parameters in a microwave design program, to predict spread in performance of the finished design.
thank you very much. this data has been very usefull :)