Design and test of a W-band photonic bandgap extended interaction Klystron amplifier

This report summarizes the progress of experimental efforts for the development a 94 GHz extended interaction klystron (EIK) with a photonic bandgap (PBG) based interaction structure. Input return loss measurements of the interaction structure are presented, demonstrating the successful fabrication of the input and output cavities of the EIK. Additionally, input return loss and insertion loss measurements of microwave-vacuum feedthrough windows are also presented. Finally, a review of the complete W-band experimental apparatus is given. Hot test experimental efforts for this study are expected to be completed by the 2018IVEC meeting.