EM Design and Analysis of FSS based Low Observable Antenna

Frequency selective characteristics of printed patterns are employed for the structural RCS reduction of planar antennas, in view of stealth applications. A high impedance FSS based electromagnetic absorber, which exhibits its absorber characteristics in Ku-K band is incorporated with an X-band patch array. Thus, this configuration can act as an absorber in the high frequency region. Further, a low pass FSS is included in the ground plane to deal with the RCS reduction in the low frequency region. A 1×4 linear patch array is designed at 8.84 GHz with cross dipole FSS-RAS elements on the substrate, along with a hybrid ground plane. This composite structure shows a maximum out-of-band structural RCS, −12.85 dBsm and −2.83 dBsm in-band structural RCS reduction without any adverse effects on the radiation performance of the reference antenna array.