Design and electromagnetic properties of conformal single-patch microstrip antennas integrated into three-dimensional orthogonal woven fabrics

As one of the efficient structures for soft body armor, the three-dimensional (3D) woven structure has relatively good properties. In this study, the concept of conformal microstrip antennas integrated into the 3D woven structure is proposed, which is anticipated for application in the modern wireless communication. For comparison, the microstrip antennas with the copper foil patch and copper yarn patch are both fabricated. The return losses of the antennas show that both of the antennas have adequate values with the resonant frequencies in the L band range. The main beam level and the gain of the copper yarn patch antenna are lower than those of the copper foil patch antenna, mainly due to the relatively low electrical conductivity of the patch. Under certain curvatures, the return loss and radiation pattern of the curved antenna are not significantly different from those of the planar one, indicating good conformability of this type of antenna.