Numerical study of the homogeneous and inhomogeneous magnetic field effects on the plasma‐based radar cross‐section reduction

A numerical method based on the recursive convolution finite difference time domain was used to calculate the radar cross‐section (RCS) of a square target under different conditions. The results indicate that for electron number density below 10 16m − 3 , unmagnetised plasma provides better RCS reduction compared to magnetised plasma. For this range of electron density, the wave bending plays an important role and its effect is stronger than the resonant and non‐resonant absorption. For densities higher than 2 × 10 16m − 3 , and for collision frequencies less than plasma frequency, magnetised plasma causes greater RCS reduction compared to unmagnetised plasma due to strong resonant absorption. In this situation, the inhomogeneous magnetic field is preferred because of its broader bandwidth. The enhanced bandwidth is due to multi‐resonance absorption of the inhomogeneous magnetic field. For collision frequencies above the plasma frequency, resonance absorption weakens and non‐resonance absorption prevails. Then in this range of plasma parameters, the unmagnetised plasma is the proper choice for optimum RCS reduction.