Commun. Comput. Phys., 15 (2014), pp. 895-910. |
Radar Cross Section Reduction of a Cavity in the Ground Plane Gang Bao ^{1*}, Jun Lai ^{2} 1 Department of Mathematics, Zhejiang University, Hangzhou 310027, Zhejiang, China; Department of Mathematics, Michigan State University, East Lansing, MI 48824, USA.2 Department of Mathematics, Michigan State University, East Lansing, MI 48824, USA. Received 9 April 2013; Accepted (in revised version) 13 September 2013 Available online 21 January 2014 doi:10.4208/cicp.090413.130913s Abstract This paper investigates the reduction of backscatter radar cross section (RCS) for a rectangular cavity embedded in the ground plane. The bottom of the cavity is coated by a thin, multilayered radar absorbing material (RAM) with possibly different permittivities. The objective is to minimize the backscatter RCS by the incidence of a plane wave over a single or a set of incident angles. By formulating the scattering problem as a Helmholtz equation with artificial boundary condition, the gradient with respect to the material permittivities is determined efficiently by the adjoint state method, which is integrated into a nonlinear optimization scheme. Numerical example shows the RCS may be significantly reduced. AMS subject classifications: 35Q93, 35J05Notice: Undefined variable: pac in /var/www/html/readabs.php on line 165 Key words: Optimal design, RCS reduction, adjoint method, radar absorbing materials. *Corresponding author. Email: bao@math.msu.edu (G. Bao), laijun@msu.edu (J. Lai) |