New design of Identification between Friend or Foe antenna embedded in planar array antenna

This paper provides a new design of IFF(Identification between Friend or Foe) antenna based on monopole element for planar array antenna system, where the center frequency is f₀ with 9.5% bandwidth. The antenna is of maximal gain 4dB at the center frequency, 3 dB beamwidth of 100° in E-plane (phi=90 deg) and 152° in E-plane (phi = 0 deg). In antenna design, compactness and stability of the presented antenna are considered firstly, which are very important in practical airborne environment. Furthermore, one of the most excellent achievements is of low altitude with height less than 0.16 λ, sheet substrate with thickness 2.032 mm extremely and can be embedded in planar array with narrow slot.