Layout of a broadband circular waveguide to coaxial transition

[[abstract]]Broadband coupling of higher order cavity modes to an external load is one way to suppress multibunch instabilities in electron storage rings. A numerical study is presented on the transmission properties of a waveguide to coaxial transition which features a double-ridged waveguide with circular cross section. Optimization using the HFSS program results in a design configuration with broadband RF transmission. Such a transition combined with a broadband coaxial vacuum window allows the rf-absorbing material to be placed outside the vacuum.[[fileno]]2010126010073[[department]]物理