Forced Convection Cooling Antenna Array With Reduced Radar Cross Section

A prototype is proposed to integrate heat dissipation and low scattering in an active slot antenna array system. The antenna system consists of a liquid absorber and a 4 × 4 slot antenna array. A liquid metamaterial absorber composed of a 3-D transparent printed container and an alcohol solution is codesigned to achieve the dual functions of radar cross-section reduction (RCSR) and heat dissipation with minimal impact on the antenna's radiation performance. Two rows of metal vias parallel to the gap and connecting the radiant layer to the ground plate are used to provide a thermal flux path from the heat source at the bottom of the antenna to the liquid. The design process of the combination of absorber and antenna is described, and the thermal resistance model is introduced to analyze the heat transfer mechanism. The radiation efficiency of the antenna array is up to 73.4%, and the realized gain is reduced by 1 dB compared with the reference antenna. The simulation and test results show that the proposed integrated antenna array can achieve an average RCSR of about 14 dB at 2 GHz to 18 GHz and has a remarkable cooling effect. The proposed array prototype is expected to be used in high-power array antennas such as phased array antenna systems.