Transverse probe antenna element embedded in a flared notch array

Abstract

Low frequency radiating elements are embedded in a flared notch array. The flared notch array forms a series of parallel troughs in which absorptive loads are placed to reduce the antenna radar cross section. The low frequency radiating elements are embedded in the array transverse to the troughs at or below the level of the absorptive loads, and excite several troughs. The absorptive load material is absorptive in the operating band of the flared notch array, but appears as a relatively low loss dielectric at the lower frequencies of operation of the low frequency radiating elements. The low frequency radiating elements can perform Identify Friend or Foe functions in the UHF and L-band regions of the spectrum, while the flared notch array operates at X-band.