Dual-Polarized Tapered Slot-Line Antenna Array Fed by Rotman Lens Air-Filled Ridge-Port Design

A novel ridge-port Rotman-lens is described, which operates as a lens with tapered slot-line ports. The lens parallel-plates mirror the ridge-ports to tapered slot-line ports. The lens height is half the height of the antenna array row, and two lenses can be stacked and feed one dual-polarized antenna array row, thus yielding a compact antenna system. The lens is air-filled, so it is easy to manufacture and repeatable in performance with no dielectric tolerances and losses, and it is lightweight compared to a dielectric lens. The lens with elongated tapered ports operates down to the antenna array low frequency, thus utilizing the large antenna bandwidth. These features make the ridge-port air-filled lens more useful than a conventional microstrip Rotman lens.