Abstract: A method for characterization of fixture utilizes a mirror symmetric THRU structure and either a HALF-THRU with a LOAD shunted to ground or a THRU with a LOAD shunted to ground located at the mirror reference plane. The method extracts the short, open, and thru measurements from the THRU structure due to the mirror symmetry. The HALF-THRU with a LOAD or the THRU with a LOAD shunted to ground located at the mirror reference plane provides the independent measurement to fully characterize the fixture. The resultant impedance or scattering parameter HALF-THRU model may be used in de-embedding a Device-Under-Test, a calibration routine, or computational simulations. The parameters of a HALF-THRU model may be stored in a memory storage circuit affixed to the associated HALF-THRU fixture. Some embodiments may include at least one memory storage circuit that attaches to the HALF-THRU fixture body affixed to an interposing matable connector.