An S/X Dual-Band Shared-Aperture Phased Array Antenna

This paper proposes an ultra-low profile S/X dual-band shared-aperture phased array antenna (SAPAA), which can achieve 2-Dementional (2-D) wide beam coverage in both S and X bands. A novel stacked metamaterial-based mushroom structure is proposed to ensure the 2-D wide beam coverage in both bands. Meanwhile, structure reuse technology is employed to reduce the entire profile significantly. The antenna described in this paper consists of a triangular array with 11 S-band metamaterial elements and a grid array with 8x16 X-band patch elements. To reduce the array spacing of the two bands, a metamaterial-based mushroom structure for S-band is stacked by an X-band patch antenna. This novel stacked mushroom structure ensure the array spacing is about 0.5 lambda(0) in both two bands to support the wide beam coverage. Moreover, the structure reuse technology, where the shorting pin of mushroom structure for S-band is the feeding pin of the patch antenna for X-band, simplifies the structure to reduce the profile significantly. Finally, a prototype is fabricated through the multi-layer printed circuit board (PCB) manufacturing process to validate this shared-aperture design. Experimental results shows that the 2-D wide beam coverage up to 50 degrees in S and X bands are achieved with the entire profile is lower than 0.05 lambda(L0).