This paper presents an optimized design and preliminary test result of a high-power input coupler. The design is motivated by five-cell Petra-type cavities operating in the Southern Advanced Photon Sources booster. We optimize the design of the high-power input coupler from the prototype. including the window geometry redesign and multipacting analysis to meet a 250 kW operation power... https://goodvibesbadhabiters.shop/product-category/stripper-pole/