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farshad Sohbaztadeh Lonbar

farshad Sohbaztadeh Lonbar

Academic rank: Professor
ORCID:
Education: PhD.
ScopusId:
Faculty: Science
Address:
Phone: 9125155360

Research

Title
Radar cross-section reduction by tunable low-pressure gas discharge plasma
Type
JournalPaper
Keywords
Plasma-based Radar Cross Section Reduction (RCSR), plasma density, collision frequency, microwave interferometry, Naval Research Laboratory (NRL) Arch Reflectometry, low-pressure gas discharge, plasma stealth technology, plasma absorber, plasma scattering.
Year
2020
Journal Journal of Physics D: Applied Physics
DOI
Researchers hadi zakeri khatir ، Ebrahim Hajiebrahimi ، farshad Sohbaztadeh Lonbar

Abstract

Abstract. In this experimental research, the effect of the tunable low-pressure gas discharge plasma was examined on the Radar Cross Section (RCS) reduction. The quintet array of plasma tubes (PAr=10torr, PHg ≈ 2-6×10-3torr, Rin=18mm) next to each other was used to reduce the radar cross-section of a planar metallic target. Plasma columns were optimized to have minimum axial and temporal inhomogeneity. Plasma electron density, plasma frequency, and collision frequency of plasma tubes were measured by fast time-resolved microwave interferometry with simultaneous measurement of current and voltage. The influence of the discharge current (Irms=50-1500 mA) as a regulator of plasma parameters was investigated. RCS reduction changes were observed by versus plasma parameters at the 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 (<-10dB) in TM polarization for 300mA discharge current (42.5% total bandwidth) and in TE polarization for 1400mA 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.