Wideband RCS reduction of slot antenna array by using reflectarrays

According to the principle of reflectarray, this paper presents a new way which disperses the scattered energy into different directions to reduce the RCS of the slot antenna array, preserving its radiating performance at the same time. Four reflectarrays are designed using double square ring elements of variable size, and they are loaded onto the patch side of the slot antenna array by region. The reflectarrays disperse the scattering field into different directions, which makes a significant reduction of monostatic RCS in a wide frequency band including in-band and out-band. The backward RCS of the slot antenna array with reflectarrays can be reduced as much as 20dBsm compared to that of the conventional antenna array.