Review of integrated millimeter wave tapered slot antennas and arrays

Progress toward the development of endfire antenna elements of the tapered slot antenna (TSA) type is discussed. The elements used both as single elements and in arrays. TSAs utilize a tapered slot in the metalization on a thin dielectric substrate to radiate in the endfire direction. The special case of air dielectric is investigated. Some distinctive advantages of the TSA elements are: (1) the 3 dB beamwidth can be varied over a wide range, down to about 15 degrees; (2) ease of fabrication by photoetching, and integration with active elements; (3) high packing density when used in arrays; and (4) high efficiency in phased arrays even with element spacings greater than 1 lambda . Applications include multibeam systems, quasi-optical power-combining, and scanned arrays for tracking systems. The author reviews the status of the theoretical understanding of TSA elements and arrays and gives examples of typical applications.<>