We developed a mantle-cloak antenna by controlling the surface reactance of a dielectric-loaded dipole antenna. First, a mantle-cloak antenna with an assumed ideal metasurface sheet was designed, and band rejection characteristics were obtained by controlling the surface reactance of the mantle cloak. The variable range of the frequency spacing between the operating and stopband frequencies of the antenna was clarified by changing the value of the surface reactance. Next, a mantle-cloak antenna that uses vertical strip conductors was designed to clarify the characteristics and operating principle of the antenna. It was confirmed that the stopband frequency was 1130MHz, and the proposed antenna had a 36.3% bandwidth (|S11| ≤ -10dB) from 700 to 1010MHz. By comparing the |S11| characteristics and the input impedance characteristics of the proposed antenna with those of the dielectric-loaded antenna, the effect of the mantle cloak was confirmed. Finally, a prototype of the mantle-cloak antenna that uses vertical strip conductors was developed and measured to validate the simulation results. The measurement results were consistent with the simulation results.

An accurate numerical solution is presented for the electromagnetic scattering from infinite strip gratings attached to both sides of a dielectric slab. This structure is a model of polarization discriminating devices. The period of the strips is common to both planes, but the widths and the axes may be different. The direction of propagation and the polarization of an incident plane wave are arbitray. We derive a set of singular integral equations and solve it by the moment method, where the Chebyshev polynomials are successfully used as the basis and the testing functions. This method is accurate and effective owing to the incorporation of the edge condition and the decomposition of the kernel functions into the singular and the regular parts. Numerical calculations are carried out for the purpose of designing polarization discriminators, and it is shown that the band width is widened by decreasing the permittivity of the slab. The cross-polarization characteristics at skew incidence are also discussed.