ENG–DPS paired metamaterial structure to alleviate RF blackout of reentry spacecraft

A hypersonic spacecraft entering the atmosphere experiences radio frequency (RF) blackout resulting from the attenuation of RF signals due to the plasma sheath formed around it, and thus, alleviating such RF blackout is of great significance for ensuring the stability of real-time communications of the spacecrafts. In this paper, a novel metamaterial-based electromagnetic method for alleviating RF blackout is proposed and theoretically studied. A pair of epsilon-negative (ENG) and double-positive (DPS) materials matches well with a thick plasma layer at certain frequencies, significantly alleviating the attenuation of RF signals within the frequency band. We first analytically determined the optimal performance of an ENG–DPS–plasma layered structure using transfer matrix method-based MATLAB optimization code and then designed a realistic metamaterial structure corresponding to the optimal ENG–DPS pair. Simulation results verify that the proposed ENG–DPS paired metamaterial structure is very useful for alleviating RF blackout during the reentry of hypersonic spacecraft.