A series tee splitter comprises a primary electromagnetic transmission line and a secondary electromagnetic transmission line that is placed in a series path with the primary electromagnetic transmission line, wherein a load is attached to the end of the secondary electromagnetic transmission line and a network analyzer is connected to opposite ends of the primary electromagnetic transmission line to measure a load impedance. This configuration increases the high impedance measurement limit of the network analyzer normally seen for reflection measurements. The series tee splitter can be electrically small to provide broadband impedance information.