Design Of Wave-absorbers With LHM And RHM Structures And Its Properties' Stimulation

As an effective way to improve the weapon's ability of survival, attack and defense, the absorbing material has been developed by every country in this world. It also has many civil applications such as information propagation, electronic instrument and defense for microwave radiation. Thus, it is very important to investigate the absorption ability of the new materials.In 1968, Ex-Soviet Physicist Veselago analyzed the conditions for the realization of the medium with both negative permittivity and permeability by applying the Electronic Dynamics theory. He also proved that the electromagnetic wave will represent many strange properties when it propagates in this medium, such as negative refraction, reversed Doppler Effect and reversed Cherenkov radiation. Meanwhile, the electric field vector, the magnetic field vector and the wave vector form a left-handed system. Therefore, this material is named as left-handed material. In 2001, this theory was experimentally verified by D.R. Smith, etc. The research of this material becomes a hot topic due to its many strange properties.Based on existed research result of the absorbing materials, in the condition of oblique incidence, the selection principle of the electromagnetic parameters is induced in this paper for the single and double layer absorbers (six kinds in total) which made of the left-handed material (LRM) or right-handed material (RHM) respectively, and the structure of the absorber is optimized employing Genetic Algorithm method and computer stimulation. The absorption ability of these absorbers is investigated and stimulated in the frequency range from 2GHz to 18GHz. According to the stimulation result, the influences of the electromagnetic parameters, the thickness of the medium, and the incident angle on the absorption ability are analyzed.The result of research shows that, in certain frequency band, there is only one absorption peak in the absorbers made with the RHM, but there are several absorption peaks in the absorbers which include the LHM. And in these six kinds of absorber, the average absorption loss of the absorber made with RHM-LHM is largest, the absorption ability of the absorber made with LHM-LHM in the low frequency band is best.Presently, in the condition of oblique incidence, the report about the selection principle of the electromagnetic parameters for the single and double layer absorber when the reflectivity is Zero is not found, and the investigation for the influence of the structure parameters on the absorber made with LHM is also seldom reported. It is expected that this paper might be some references for the researchers working in the LHM or wave-absorbing materials fields.