Radar cross-section reduction by tunable low-pressure gas discharge plasma

Abstract

In this experimental research, the effect of tunable low-pressure gas discharge plasma was examined on radar cross -section (RCS) reduction. A quintet array of plasma tubes (P Ar = 10 torr, P Hg ≈ 2-6 × 10 −3 torr, R in = 18 mm) next to each other was used to reduce the RCS of a planar metallic target. Plasma columns were optimized to have minimum axial and temporal inhomogeneity. The plasma electron density, plasma frequency, and collision frequency of the plasma tubes were measured by fast time-resolved microwave interferometry with simultaneous measurement of current and voltage. The influence of the discharge current (I rms = 50-1500 mA) as a regulator of the plasma parameters was investigated. RCS reduction changes were observed by tuning plasma parameters at a frequency range of 2-18 GHz for the normal and oblique incidence of TE and TM polarizations. The assembled plasma tubes depicted broadband RCS reduction (<−10 dB) in TM polarization for a 300 mA discharge current (42.5% total bandwidth) and in TE polarization for a 1400 mA discharge current (34% total bandwidth) for normal incidence. It was shown that the measurement is in good agreement with the simulation. It was concluded that by performing bistatic measurements, the plasma cylinders behave as a wave absorber and scattering object in the TE and TM polarizations, respectively.

Design of a wideband and tunable radar absorber

“…= ´Hz and 4.5 10 10 ´Hz [22,31,54]. The RAM sample, as shown in figure 3(a), was fabricated into toroidal shapes, and then tested using the coaxial-line method [7] with a vector network analyzer (CETC, AV3672C).…”

“…Due to the difficulty associated with generating and maintaining a certain density of plasma in a lowaltitude open environment [43,44] the plasma in the closed cavity with low gas pressure is used in this paper. High-purity argon is used to fill the closed cavity, which is made of glass with a thickness of t glass and a permittivity of 3.8 [31,45] and the thickness of plasma is denoted as t . plasma One of the most common methods for generating plasma is by applying an electric field to the neutral gas [38,46].…”

“…Consequently, extensive research efforts have been devoted to studying the interaction between electromagnetic and plasma [22,29]. The electromagnetic properties of plasma are influenced by plasma frequency and collision frequency [30,31], which can be effectively adjusted through external excitation. This characteristic makes plasma an ideal active material for manipulating electromagnetic wave.…”

Recent Progress on Plasmonic and Dielectric Chiral Metasurfaces: Fundamentals, Design Strategies, and Implementation

“…Owing to such limitations, researchers came up with algorithmic optimization approaches to ease the design process of metasurfaces. In general metasurface design, such approaches comprise genetic algorithms, [111][112][113] adjoint state method, [114,115] topology optimization, [115][116][117][118][119] etc. Later, these methods were improved to lower the simulation time and utilized in the design and optimization of metasurfaces.…”

Factors influencing the electromagnetic transmission of mercury vapor discharge plasma tube arrays

“…Low-pressure Mercury vapor discharge plasma has the advantages of low power consumption, large amount of generated plasma, long-term stable maintenance, mature technology, and low cost. Further, such plasma has been widely used in research focusing on the interaction between plasma and electromagnetic waves [17][18][19][20][21][22][23][24][25][26][27][28].…”