Adaptive Compensation of Flexible Skin Antenna With Embedded Fiber Bragg Grating

Skin antenna can be installed in the structural surface of an aircraft, warship, or armored vehicle. The radiation pattern is inevitably degraded due to the antenna surface deformations caused by external loads in service. This paper proposes a new skin antenna named smart skin antenna that consists of an antenna array, a protective layer (facesheet and honeycomb core), and a sensing layer with fiber Bragg grating (FBG) sensors. The shape of a deformed skin antenna was calculated using a strain-displacement transformation according to the measured strains from limited FBG sensors. Moreover, a strain-electromagnetic coupling model between the phase compensation values and the measured strains was derived for the first time to adaptively compensate the deterioration of radiation patterns caused by various flexible deformations. An 8 × 4 skin antenna prototype at 5.8 GHz was fabricated, and some experiments were carried out. The measured results demonstrate that the proposed compensation method can effectively correct the deterioration of radiation patterns.