Ultrawideband tightly coupled array for multiband communications at S-X frequencies

In satellite-borne platforms where the reduction of size, weight and power are very critical design factors. To pursuing to this goal, we present a design for ultrawideband tightly coupled antenna array (TCDA) with wide angle scanning and low cross polarization. Although TCDAs possess the merit of wideband, wide-scanning performance, they need a balanced feeding structure which introduces several practical challenges. In this paper, we demonstrate a low-cost wideband integrated balun to incorporate with array and increase overall bandwidth. The final array is capable of working simultaneously on numerous communication bands, including S, C, and lower-X bands (2-10GHz). Besides, the array shows ±45° scanning in all planes, and less than - 15dB cross-polarization. To validate the design, an 8 × 8 TCDA prototype is fabricated and measured.