Abstract: An antenna feed network for forming and steering a phased array antenna beam. The feed network includes a plurality of dual parallel microwave transmission paths for each array element. To form and steer the beam at the correct spatial angle each pair of paths is shorted at the appropriate location to provide a time delay for the wave traversing the path. Each signal of the plurality of signals drives a different element of the antenna array with the proper phase to form and steer a beam from the array. The feed network is linear and reciprocal and can therefore be used in a transmit or receive antenna array. A ferrite circulator can be used to generate the time delayed signals on the short circuited transmission line. However, this antenna is not reciprocal and must be adjusted for either a particular receive or transmit beam position.

Abstract: An electrically small, dual polarized, hemispherical coverage, multi-element adaptive array antenna exhibiting low VSWR and operational over an octave of bandwidth is flush-mounted with the airframe structure of high performance aircraft. The antenna is configured as a cavity type structure in the shape of a regular polygon and has a plurality of radiation elements mounted on an insulative support board, each of the elements being is connected to a respective output port for use in a multi-channel adaptive array system. The array provides broadband capability of nulling interfering sources having arbitrary polarization and spatial direction.

Abstract: An antenna configuration capable of providing either shaped conical or uniform hemispheric coverage to circularly polarized signals from a very thin or flush mounted radiation structure. For this purpose, the antenna is configured of an array of (N=three or more) radiation elements fed in phase rotation (i.e. 360.degree./N phase difference between elements) to provide circular polarization. These elements may be short asymmetrically top loaded stubs, unbalanced slots, "L" type stubs, "U" shaped slots or other types of unbalanced elements which provide null free coverage in a hemisphere. The shape of these elements and their position in the array control the desired shaping of the antenna pattern.The antenna elements are provided on a first printed circuit board that is spaced apart by a thin dielectric spacer from an impedance matching/phasing network such as from 90.degree. and 180.degree. hybrid networks formed on a second printed circuit board.

Abstract: A phased array antenna is disclosed including a central reference element. This is surrounded by a plurality of sub-elements which form the adaptive elements of the array and have no feed networks. Each adaptive element is essentially an "L" stub, with the adaptive elements oriented such that the "L" top loading is circumferential around the reference element. The plurality of adaptive elements, all with different orientations of the linear top loading allows the complex weights and adaptive nulling algorithm to generate any required polarization, and form an adaptive null to any arbitrary polarized interferring signal as required.