Mesh-based antenna with broadband transparency for dual-band shared-aperture array

Abstract

Mesh-based antenna with broadband transparency for a dual-band shared-aperture array is proposed in this design. The low-radar cross section (RCS) frequency selective surface (FSS) cell is obtained firstly by combining the capacitive and inductive strips. It can be found that the electromagnetic (EM) transparent bandwidth across the high band (HB: n77) of the FSS can be enhanced by increasing in the number of strips. Then the low band (LB) antenna composed of low-RCS mesh-based elements is constructed. Remarkably, the EM transparent characteristic and the LB working performance can be individually controlled, avoiding time-consuming optimization. Subsequently, the LB transparent antenna is introduced into the array to eliminate the blockage effect on the HB antenna. The radiation patterns of the HB antenna are recovered well across the entire HB. Finally, the array prototype is fabricated and measured results show that the array covers a dual band of 1.7–2.7 GHz (45%) and 3.3–4.2 GHz (24%), showing stable radiation patterns in both LB and HB antennas. The average gains of the LB and HB antennas are 8.64 dBi and 8.58 dBi, respectively. The results verify that the proposed broadband transparent mesh-based antenna is attractive in the shared-aperture array.