Simulation of radiation characteristics of antenna array under the influence of ablation

When aircraft re-enters atmosphere at high speed, the plasma emerged in the high temperature flow will have a certain influence on the transmission characteristics of electromagnetic(EM) waves, and even cause the blackout phenomenon. In this paper, the impedance matching characteristics and radiation characteristics of microstrip array antenna coated by inhomogeneous plasma are simulated with the coupling of the ablation effect. The variations in return loss and gain of the antenna array are calculated and compared with numerical WKB method, and an analysis is conducted to evaluate the influence of four different high temperature gas models.The radiation characteristics of the antenna array are also obtained under three different rotating angles (10°, 15°, 30°). The results show that at an altitude of 25km, the transmission attenuation of EM wave is most severe, the influence of ablation products and alkali metal impurity on the transmission attenuation of EM wave are both significant. The presence of plasma distort the antenna array’s radiation pattern significantly, which degrades the radiation performance in the desired direction. Increasing the rotation angle leads to a reduction of the HPBW of the antenna array, which results in a better directionality. This paper provides an effective approach for solving the blackout problem with the consideration of the ablation effect during the reentry stage of high-speed aircraft.