Electromagnetic Shielding in the near Field

This paper presents a general engineering technique by which the shielding effectiveness of solid single-layer shields may be analytically evaluated. Shielding equations applicable to any homogeneous isotropic material are developed using the transmission-line approach of Schelkunoff. Corresponding limitations are discussed. Necessary information regarding near-field wave impedance is presented in normalized graphs. A useful computer program (FORTRAN IV) is given, together with application information. Calculated results are compared with corresponding test data.