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Dipole Moments of Weak, Electrically Small Emitters from TEM-Cell Measurements



David A. Hill, Kenneth H. Cavcey


This report presents a new method for determining the equivalent electric and magnetic dipole moments of an electrically small emitter from TEM-cell measurements. The electric dipole moments are determined from open-circuit measurements, and the magnetic dipole moments are determined from short-circuit measurements. The method has the advantages of simplicity in separating the electric and magnetic dipole emissions and increased sensitivity resulting from the in-phase reflection from the open- or short-circuited port. The method has been used on two commercial electronic timers, and in both cases the electric dipole moment was measurable, but the magnetic dipole response was below the noise floor. These results have practical application to the problem of detection of electronic bomb detonators.
NIST Interagency/Internal Report (NISTIR) - 5079
Report Number


capacitance, dipole moment, electrically small emitter, electric dipole, inductance, magnetic dipole, quasi-static fields, reciprocity, TEM cell


Hill, D. and Cavcey, K. (1998), Dipole Moments of Weak, Electrically Small Emitters from TEM-Cell Measurements, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD (Accessed April 19, 2024)
Created December 1, 1998, Updated February 19, 2017