Radiation Resistance of Resonant Impedance Monopole Placed on Metal Square Screen

Abstract

The asymptotical solution of the 3-D vector problem of diffraction of the field of the monopole with the uniform distributed surface impedance, placed on the ideally conducting rectangular screen with the sides sizes L and $W$ is obtained. Within the frame of the uniform geometrical theory of diffraction the radiation field in a far zone is represented as the sum of the geometric optics field from an impedance monopole placed on infinite screen, and the diffracted fields from the rectangular screen edges. The radiation resistances are calculated by the Poynting vector method as the functions of the monopole's surface impedance and the sizes of monopole and screen. The input impedances of the same monopoles on the square screens have calculated using commercial software too. It is shown that at all surface impedances and monopole's lengths the radiation and input resistances reach maximum at L=W=0.9of wavelength.