Equivalent circuit representation of stripline step discontinuity for multilayer MMIC applications

Multilayer realization of three-dimensional (3D) MMIC has been applied to reduce the cost and size of microwave circuits for commercial applications. The lack of computationally efficient and accurate models for basic microwave components makes the circuit optimization difficult and inefficient. An equivalent circuit representation for the step discontinuity in an inhomogeneous multilayered structure is presented. Based on the curve-fitting technique, the circuit representation is valid over a wide range of parameters covering most practical cases. The accuracy of the circuit representation makes a powerful tool when used in combination with other circuit based optimization programs.