Abstract: In order to resolve the fracture failures of power splitter-coupler assembly mounting lugs of an airborne conformal antenna aperture during random vibration, failure mechanism analysis of the fault phenomenon was conducted.The validity of the identified mechanism was rigorously verified through numerical simulation and experimental testing.Based on the failure mechanism,structural and process optimizations designs were implemented for the power splitter-coupler assembly.The strength safety margin of the optimized mounting lugs and fastening screws under random vibration conditions was evaluated using a combined approach of numerical simulation and theoretical calculations.Finally,the effectiveness of the optimization measures was conclusively validated through qualification testing. The conclusions indicate:Flatness and perpendicularity mismatches in over-constrained multi-plane installations necessitate mounting clesrances reduction via shimming spacers.In structural design for airborne equipmengt,extended mounting lugs are strongly discouraged.If unavoidable under design constraints,the strength safety margin should be maximized while ensuring weight requirements are met.