Robust design of absorbers using genetic algorithms and the finite element-boundary integral method

Properly designed anechoic chambers are crucial to the experimental characterization of antennas and scatterers. The walls of an anechoic chamber are lined with lossy material to simulate a free space environment. The front surface of the absorber is often a periodic structure that reduces reflection from the air-absorber interfaces. This paper presents a method to design high performance periodic absorbers backed with a perfect electric conductors (PEC) using genetic algorithms (GAs). Genetic algorithms (GAs) have become very popular in electromagnetic design due to their robustness, capacity to search without gradient information, and ability to operate on discrete and continuous parameters simultaneously. The objective function optimized by the GA is derived from the finite element-boundary integral (FE/BI) method, which has a relatively simple formulation and is thus attractive for simulating complex inhomogeneous lossy or penetrable structures with conductors of arbitrary cross section.