Electromagnetic Field Propagation Characteristics of a Contactless Setting of Fuze

摘要

The electromagnetic field propagation characteristics of a contactless setting of fuze are proposed. Its typical scheme that includes two coils, an insulated resin cylinder and a metal hemisphere shell, is set up. Firstly, the near field is non-uniform spherical waves. Secondly, the electric field intensity vector E is parallel to xOy plane, while the magnetic field intensity vector H exists in arbitrary direction; the vector E only has a transverse component, which is perpendicular to its propagation direction, while the vector H has both transverse and radial ones. Thirdly, the amplitude of vector E is inversely proportional to the square of distance, while the amplitude of vector H inversely proportional to the cube of distance; both vectors E and H are directional. Fourthly, when latitude angle θ is equal to 90~0, the amplitude of E is maximal, and it is zero as θ is equal to 0~0; when latitude angle θ is equal to 0~0, the amplitude of H is maximal, and it is minimal as θ is equal to 90~0. For E-plane, the beam width 2θ~0 between zero power points is 180~0, while the beam width 2θ_(0.5) between half power points is 90~0; for H-plane, the beam width 2θ~0 does not exist; the beam width 2θ_(0.5) is 2arcsin[(2/3)~(0.5)]. Fifthly, there are reflection waves on the surface of both the insulated resin cylinder and the metal hemisphere shell that produce a full reflection phenomenon; it is possible to produce full transmission phenomenon on the surface of the cylinder. An experimental example is presented for verifying these theoretical predictions.