Design and characterization for a high-temperature dual-band radome wall structure for airborne applications

Modern aircraft have reached higher and higher flight speed, resulting in the urgent demand of design and characterization for high-temperature airborne radomes, especially for those with dual-band or multi-band properties. In this paper, an A-sandwich radome wall structure made of quartz is designed for both centimeter and millimeter wave applications at high temperatures. Its transmission performance in the 4-40 GHz frequency range at ambient temperature to 800 degrees C is characterized by a broadband free-space microwave measurement system, which is mainly composed of a vector network analyzer, spot-focusing lens horn antennas, and a furnace for heating sample. A calibration method is proposed to eliminate the temperature-dependent distortion of microwave signals by the microwave-transparent walls of the furnace, and the errors caused by the wall position variations as well. Transmission measurements show that the radome wall structure is feasible for dual-band applications in the 4-10 GHz and 24-40 GHz frequency spans with the transmission efficiency higher than 70% at temperatures up to 800 degrees C, and demonstrate the effectiveness of the design method. It can be expected that the free-space microwave measurement system in conjunction with the proposed calibration method is capable of damage detection for aerospace structures under high-temperature conditions. (C) 2016 Elsevier Ltd. All rights reserved.National Natural Science Foundation of China [11522214, 1191216301, 11227801, 11232001, 11602087]; Beijing NOVA Program [Z151100000315041]; China Postdoctoral Science Foundation [2016M602457]; Natural Science Foundation of Guangdong Province [2015A030311046, 2015B010131009]SCI(E)ARTICLE264-27011