Attenuating Broadband Electromagnetic Waves in Dielectric-Barrier Discharge Plasmas

Aircraft stealth by avoiding radar detection relies on shape and materials, but these are ineffective in attenuating electromagnetic (EM) waves in the ultrahigh frequency (UHF) band. This article investigates broadband EM wave attenuation in dielectric-barrier discharge (DBD) plasmas. We used a simplified collisional-radiative model to determine the electron density distribution using 2-D emission spectra and found that the gas pressure has a great effect on electron density. An empirical relationship between the gas pressure and electron density is given. We introduce a parameter optimizing method for multilayer plasmas that combines the attenuation characteristics of EM waves in plasma. We also establish an ideal multilayer plasma model to calculate the EM wave attenuation in the UHF band. The results show that multilayer plasmas can effectively enlarge the effective attenuating frequency range of EM waves and also attenuate UHF EM waves. On the basis of the calculation results, we propose a single-layer plasma generator. A large-area and homogenous plasma under medium-to-high gas pressure can also be created by discharge with argon or a mixture of argon and helium.