High-speed interconnect systems for connecting two or more electrical elements are provided. Interconnect system has the means, which could reduce the microwave loss induced due to the dielectrics. Reducing the effective loss tangent of the dielectrics reduces the microwave loss. With optimize design of the interconnects, the speed of the electrical signal can be made to closer to the speed of the light. The interconnect systems consists of the electrical signal line, inhomogeneous dielectric systems and the ground line, wherein inhomogeneous dielectric system consisting of the opened-trenches into the dielectric substrate or comb-shaped dielectrics to reduce the microwave loss. Alternatively dielectric structure can have the structure based on the fully electronic or electromagnetic crystal or quasi crystal with the line defect. Alternatively, dielectric structure can be made to comb-shaped structure with teethes having thickness and space making the air pocket to reduce the microwave loss. The interconnect system, can be made in rigid or flex board for off-chip interconnects for IC packages, connectors and cables, where conventional manufacturing technology can be used and yet to increase the bandwidth of the interconnects.