Abstract: A combined antenna system mounted in a nose randome of an aircraft for both radar and ESM signals. A flat plate waveguide antenna, a twist panel, a selective reflector, and a feed are aligned along a longitudinal axis in the randome. The polarized electromagnetic energy is twisted 45 degrees; and the selective reflector passes the twisted electromagnetic energy and reflects energy polarized in planes substantially different than the twisted plane.

Abstract: Disclosed herein is a radar jammer which utilizes an electronically agile, sparsely populated, phase controlled antenna array of pseudo-randomly spaced radiating elements to form a high gain, single narrow beam of radiation directed at a detected threat radar, but containing only a small fraction of the available transmitting power, while providing simultaneously therewith effective jamming radiation over a wide coverage region. Preferably, the plurality of radiating elements are sparsely disposed pseudo-randomly over an area surface to form an antenna array, the number of radiating elements in the array being less than the value of the surface area divided by the transmitting carrier wavelength (.lambda.) squared.