The Effect of Mutual Inductance and Mutual Capacitance on the Transient Response of Braided-Shield Coaxial Cables

A quantitative comparison is made of the importance of mutual inductance and mutual capacitance in the leakage of transient signals through the braid of a coaxial cable. The difference between mutual inductance and mutual capacitance coupling is vividly exhibited in the transient predictions. Comparisons of predictions to measurements made on a length of RG-214 test cable are also included.     

Analysis of the Shielding Characteristics of Saturable Ferromagnetic Cable Shields

A numerical technique is developed that may be used to analyze the shielding characteristics of a cable with a saturable ferromagnetic outer sheath in an intense low-frequency environment. The solution relates the center conductor current to the total current exciting a coaxial cable with a ferromagnetic sheath. Several examples are given to illustrate how saturation effects the shielding properties of a ferromagnetic sheath.     

Design of Shielded Cables Using Saturable Ferromagnetic Materials

Previously, a numerical solution was evolved that may be used to analyze the effect of material saturation on the low frequency shielding characteristics of a thin ferromagnetic cable shield. Numerical solutions are difficult to employ in design problems and so a simplified theory has also been developed. This supplemental theory, described here, yields simple equations useful in the design of ferromagnetic cable shields to provide protection against some anticipated intense low frequency environment.     

Transient Currents Induced on a Metallic Body of Revolution by an Electromagnetic Pulse

A numerical technique is presented that may be used to predict the current induced on a thin metallic body of revolution excited by an electromagnetic pulse. Examples are given. Introduced here is the use of the radiation condition in a finite difference solution. This development alleviates the requirement that finite difference techniques be applied to a bounded region of space.     

Finite-Difference Analysis of EM Fields Inside Complex Cavities Driven by Large Apertures

This paper is an application of the equivalence principle to the problem of predicting the fields inside aperture-driven cavities. This approach allows the prediction of the fields penetrating large apertures into complex cavities using the finite-difference analysis procedure.     

Receiving Properties of the Small Annular-Slot Antenna

An analytical formula for the effective height of an annularslot antenna is determined using the reciprocity theorem. This result generalizes the previously available single-frequency steady-state result and yields an equivalent circuit valid for computing the transient response of the small annular-slot antenna. the theory has application in calibrating near-zone field strength instrumentation and in determining the response of an unsheathed coaxial cable connector mounted flush with the skin of a missile to intense plane-wave electromagnetic field pulses.     

Electromagnetic Pulse Transmission Through a Thin Sheet of Saturable Ferromagnetic Material of Infinite Surface Area

A numerical solution is presented for determining the shielding properties of a thin sheet of saturable ferromagnetic material of infinite surface area. Several examples are given to indicate the behavior of ferromagnetic shields in an intense electromagnetic environment. These examples illustrate that only a few numerical results are required to determine the electric field transmitted through the material for a given incident pulse of any amplitude.