Electrodynamic properties of plane wire grids

The method of submillimetre BWT-spectroscopy is used to measure electrodynamic parameters of the grids wound from conductors with circular cross sections. The coefficients of transmission and reflection, reflected wave phase, and ohmic losses in conductors are measured in the range of small values of diffraction parameteræ=D/λ<1 (λ is the wavelength,D is the grid spacing) for the case where the wave vector E is directed along the conductors (E‖1). In the diffraction region (0.5<æ<2.2), transmission spectra of the grids are measured for both polarizations. The data obtained are compared to those of different theoretical methods for describing grid electrodynamics. In particular, the transmission spectra are shown to have some peculiarities in the vicinity of sliding pointsæ=1;2 (E⊥1), unpredicted by corresponding theories.