Design of Low-RCS Antenna Using Antenna Array

In this paper, we develop an antenna array-based method to reduce the radar cross section (RCS) of the antenna. A 2×2 antenna subarray with polarization rotation characteristic is first designed. By translating the 2×2 subarray, an array with polarization rotation characteristic is generated to transform the copolarization component of the antenna RCS into the crosspolarization one. With the simultaneous rotation and translation manipulations of the designed 2×2 subarray, an array used to reduce the antenna RCS for both coand cross-polarization components is developed. Following these two design ideas, a novel 2×2 antenna array is designed and directly integrated with the antenna to achieve the low-RCS characteristic. Compared with the two above arrays having the electrical sizes of 3.55λ
₀
×3.55λ
₀
, the new design is of compact size of 1.5λ
₀
×1.5λ
₀
and gives rise to the gain improvement of 0.8 dB. The proposed antenna with low RCS is fabricated and the measured results validate the proposed design.