X band design considerations

Dear all,

please help me out with the design considerationsfor an X band upconverter application.
also please tell me how to choose a PCB for the application in case of and Airborne system,
is there any calcuations for selecting a PCB material?

As far as I know, the choice of PCB material for microwave circuits entails dielectric constant and loss tangent which result in different size and Q. Maybe airborne system has to take other properties like temperature variations and mechanical strengths as well.

Hope this helps.