Determination of Cavity Fields Excited by an Electromagnetic Pulse through an Aperture.
Interim rept., 1 May 76-31 Oct 77,
SYRACUSE UNIV NY DEPT OF ELECTRICAL AND COMPUTER SCIENCE
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The state-space technique is used to formulate the transient electromagnetic problem of excitation of a rectangular cavity through an aperture. Depending on whether the E- or the H-formulation is used, the effect of the aperture can be accounted for by a magnetic current in invoking the induction theorem or by an electric current in invoking the equivalence theorem. The governing second-order differential equation is converted into a set of first-order state equations by defining three new state variables in addition to an appropriate vector potential. These state equations are solved by the method of moments. Two cases are considered parallel polarization and perpendicular polarization. Some significant singularities for the parallel-polarization case are found and the electric intensities as functions of time at two locations in the cavity are computed for a step excitation. An alternative approach of expanding the cavity fields in terms of TM and TE cavity modes is developed to reduce the dimension of the system matrix. Numerical difficulties are encountered and possible contributing causes are discussed. Author
- Electricity and Magnetism