| In recent years, with the rapid development of science and technology, various communication applications are widely used in people’s life. Based on the inherent advantages of bigger frequency range and wide bandwidth, as well as the available of power source within the bandwidth, millimeter wave has gradually been applied in wireless communication, target alarm equipment, environmental monitoring device, remote sensing system, and so on. However, the use of various high-tech products has changed the environment in our life, and produced some positive or negative influence to the health of human or other organisms. Therefore, millimeter wave is widely used in bio-electricity magnetic application research, such as medical treatment of cornea doses and skin cancer detection. In this paper, we adopt the dosimetry of millimeter-wave in vitro on cells. The paper has finished the following three parts:(1)A cell culture model diameter of 35 mm with meniscus surface specification is constructed by using of XFDTD software. Based on the availability of computer resources, 0.125 mm grid resolution is chosen. Take the common communication frequencies of 42.3 GHz and 61.2GHz for examples and simulating the Petri-dish. We make use of the odd-even symmetry of the incident wave in E plane and H plane, optimize the problem space with two symmetrical boundary for a quarter of the original size, and adjust the location and rotation parameters of the antenna. It is concluded that the 0.125 mm resolution can provide suitable and high precision.(2) With the millimeter wave frequency of 60.5GHz and amplitude of 1V/m, the Petri-dish is simulated and calculated upon the radiation of plane wave and antenna. We take the SAR distribution of cells for research and analysis the SAR distribution of cells under different propagation direction and polarization direction. Consider of irradiation uniformity and radiation efficiency of cells, the exposure with the upward wave is confirmed for the optimization exposure. By simulation and calculation the SAR distribution of cells is obtained.Next, according to the scattering theory of incident wave on the boundary of different materials, we conclude that the main reason of exposure inhomogeneity is the scattered waves on the interface between base panel and air, and the interface between base panel and cell culture.(3) For the suppression of stair-stepped error in SAR of cells on the boundary of cells and air,the polarization direction of incident wave and the grid resolution-two main factors which influences the stair- stepped error, are adjusted to the optimum. We design algorithm of area compensation and method of local model optimum for the correction of stair-stepped error.For the algorithm of area compensation, the grids of cells and air are classified to three types respectively. Based on the location range of each cell type, we take area compensation in the form of each own type and make the coefficient correction table range ofoo900- under the resolution of 0.125 mm. For the method of local model optimum, we take the center of error corrected cell grid as the original and obtain the local model size of ××1633 under resolution of ××1633. Under the same irradiation system, the resolution of local model is 0.014 mm.By simulation and calculation,we take the SAR value of the center grid of 0.014 mm model as the accurate value. The stair-stepped error is corrected effectively. |
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