OPTIMIZATION OF A SCATTERED SIGNATURE

The optimization of electromagnetic devices governed by the Poisson eq uation is now well established. This paper extends the methodology to scattering problems. In particular, the permittivity and permeability of the coating on an aircraft fuselage and its thickness are computed so as to minimize the scattered signature. It is shown that the reflec tion coefficient has multiple minima and maxima as the thickness of th e coating is varied, thereby making search techniques superior to the usually efficient gradient methods. On the other hand, as the permeabi lity and permittivity are varied, the reflection coefficient varies gr adually to its one minimum, except for a few local minima, thereby mak ing gradient techniques very powerful.