Design of Low-RCS Antenna Using Antenna Array

Abstract

In this paper, we develop an antenna array-based method to reduce the radar cross section (RCS) of the antenna. A $2 \times 2$ antenna subarray with polarization rotation characteristic is first designed. By translating the $2\times 2$ subarray, an array with polarization rotation characteristic is generated to transform the copolarization component of the antenna RCS into the cross-polarization one. With the simultaneous rotation and translation manipulations of the designed $2\times 2$ subarray, an array used to reduce the antenna RCS for both co- and cross-polarization components is developed. Following these two design ideas, a novel $2\times 2$ 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 $3.55\lambda _{0} \times 3.55\lambda _{0}$ , the new design is of compact size of $1.5\lambda _{0} \times 1.5\lambda _{0}$ 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.