Fabrication and characterization of large free-standing polarizer grids for millimeter waves

Construction of large aperture free-standing metal wire grids is demonstrat ed for the lower end of the millimeter wave spectral region. For the constr ucted two grids the co-polarized and cross-polarized components of transmit ted power were measured at 45 degrees oblique incidence. The measurements w ere performed as a function of wire orientation angle and in more detail at selected angles. The results are in good agreement with the theoretical re sults presented in the literature. In order to save time and costs the cons truction apparatus was simplified from those reported previously by other a uthors. It was shown that for this frequency range the grid characteristics are not degraded when such an apparatus is applied. One of the constructed grids will be used in a calibration system of the Helsinki University of T echnology (HUT) polarimetric radiometer.