A Metamaterial-Based $S/X$ -Band Shared-Aperture Phased-Array Antenna With Wide Beam Scanning Coverage
Chun Xu Bai, Yu Jian Cheng, Yan Ding, Jin Fan Zhang
Abstract
This article proposes an ultralow profile S/X-band shared-aperture phased-array antenna (SAPAA), which can achieve wide beam scanning coverage in both the Sand X-bands. The SAPAA consists of an S-band array with a triangular placement that has 11 elements and a grid array with 8 × 16 X-band elements. To avoid grating lobes in wide beam scanning coverage, a metamaterial-based stacked mushroom structure is proposed to reduce the array spacing of the two bands, where an X-band patch antenna is stacked on a traditional mushroom structure. A 4 × 4 subarray of the stacked mushroom structure operates as a single antenna element in S-band. Consequently, each S-band element corresponds to a 4 × 4 subarray of the X-band element. Because a triangular arrangement in the S-band array and a square arrangement in the X-band array are employed, the array spacing of the two bands is 0.54λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L0</sub> and 0.51λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H0</sub> , respectively, which is suitable for wide beam scanning coverage. Moreover, the shorting pin of the mushroom structure is also the feeding pin of the X-band patch. This structure reuse technology reduces the whole profile to less than 0.04λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> . To verify this design, a prototype is fabricated through the multilayer printed circuit board process. It realizes ±50° beam coverage in both the Sand X-bands.