Abstract: A phased array includes a first plurality of radiators having a first polarization and a second plurality of radiators having a second polarization, different from said first polarization. The phased array is constructed such that radiating patterns of the first and second plurality of radiators are congruent. The radiators are constructed so that they radiating apertures thereof can occupy virtually the same space, i.e., the spacing of the radiating elements is less than a wavelength. Other features provided allow this compactness to be achieved. Impedance matching features are integrated into the radiators themselves. The elevation assemblies of the radiators are mated together, and then are coupled across to their respective azimuth assemblies. Two azimuth assemblies for either type of polarization may be provided when monopulse operation is required.

Abstract: A freqency selective surface for passing electromagnetic wave energy and the selected frequency band is described. The device includes a conductive apertured substrate having apertures formed therein which are sized and arranged in a predetermined patern. The apertures each form a waveguide segment for electromagnetic energy. In one embodiment dielectric loading material is moldably formed directly into the apertures. In a bipolar arrangement, conductive patches are located on opposite sides of the dielectric coaxially with each waveguide for establishing a capacitive load in accordance with the area of the patches. Dielectric matching material on opposite surfaces of the substrate is employed to match the surface with external media for efficient electromagnetic wave propagation. Other arrangements employ notched patches and air dielectrics.