Abstract: In a log-periodic monopole antenna array of the type described in U.S. Pat. No. 3,286,268, each antenna of the array having active elements spaced over the top surface of a ground structure and grounded parasitic elements interspersed between the active elements, the improvement of means for mechanically and electrically connecting the parasitic elements to a non-solderable ground structure comprising an elongated block compressed into a correspondingly shaped groove in the structure. Screw means threadedly engage the ground structure in a direction transversely of the top surface thereof and abut against the block. The lower strip portion of the parasitic elements is disposed in the groove between the block and a groove side wall and is compressed therebetween when the screw means is tightened into the structure and against the block.

Abstract: A multilayer antenna aperture polarizer comprises a single continuous electrically conductive trace on a flexible thin dielectric strip, the trace being formed into a plurality of arrays of grid lines with adjacent arrays interconnected by shorting leads and with a ground lead connected to the last or end array. The strip and shorting leads are folded at the locations of the shorting leads to form a stack of plane parallel polarizer panels, each comprising an array on the strip, adjacent panels in the stack being spaced apart in a direction transversely of the planes of the panels by insulator spacers, respectively. The polarizer is inserted in front of the aperture of the antenna and the ground lead is electrically connected to the antenna frame for grounding the several arrays. The shorting and ground leads are located at the corners of the stack in the neutral or minimum field zone of the antenna.

Abstract: A broadband (8-18 GHz) radomed horn antenna system comprises a conical horn having broadband slots on the inner surface and a radome having a frusto-conical side wall and a spherically shaped transverse wall inserted into the horn. The radome wall is thin relative to operating wavelength. The radome side wall fits snugly against the inner surface of the horn wall so that transverse wall is proximate to the horn feed port with its convex side facing toward the horn aperture. The cylindrical feed guide contains a higher order hybrid mode suppressor which maintains a substantially uniform radiation pattern over the operating band with an acceptable insertion loss.