Abstract: An ultrawide bandwidth z-axis interconnect which has a z-axis lap joint structure with embedded ground planes that self compensate for the interface misalignment and impedance mismatch. The structure acts as a low pass filter that can be tailored to meet performance requirements from DC to in excess of 100 GHz. The area required for the interface is reduced while increasing the alignment tolerance range. The interconnect structure is easily modeled as a multi-element low pass filter with interfacing transmission lines (microstrip or stripline) to allow for rapid design efforts and reduction in cycle time for a program.