Double-delay and short open calibration (SOC) deembedding are both useful for deembedding the results of a gap voltage source excited electromagnetic analysis. Previously, each approach has been viewed as distinct, each with its own advantages and disadvantages. This paper describes a unifying theory, showing that double delay and SOC are each special cases of an extended SOC technique. Results related to the characteristic impedance as determined by this extended SOC deembedding are also presented.