| In the field of radio technology, the antenna has been playing an irreplaceable role for the transmissions between different equipments. The microstrip antenna, as one special kind of antennas, has various characteristics including low section, performance diversification, small volume, light weight and ease of integration, thus it can be made into the multi-functional and conformal antennas. In recent years, with the continuous development of science and technology, as well as the wide utilization of the microwave band, the research of the microstrip antenna has been moved towards increasing sophistication. The paper mainly focuses on the research of the microstrip antenna with dual V-shaped slots and low power consumption, which is widely used for the interior short-distance transmissions. Its operating frequency is between 2.2 GHz to 2.4 GHz,with symmetric and bi-directional radiation direction. Furthermore, the paper analyzes and interprets the environmental adaptability and the radiant effects on human bodies of the microstrip antenna.First of all, the whole design idea of the microstrip antenna has been proposed according to the equivalent principle of microwave circuit and the performance requirements of the antenna. The size of the antenna has been determined on the basis of particular analysis and accurate calculation for the antenna equivalent circuit. Then the simulation model has been established with the utilization of XFDTD software,calculating and analyzing various performance parameters including the antenna gain,efficiency, directivity etc. Secondly, the research means to improve the radiation capability of the antenna by changing the structure of the slots and converting the distribution characteristics of the surface current, on the basis of the results for analyzing antenna performance parameters. Finally, the simulation has been applied for the enhanced antenna model, verifying that the optimization for the antenna can be achieved after improvement.The paper further interprets that the simulation for the interior transmission effect of the microstrip antenna with dual V-shaped slots has been conducted, analyzing the magnetic properties of two different indoor models with different concrete structures. Firstly, the two different indoor models have been established for analyzing the simulation magnetic results for the microstrip antenna operating in different indoor environments.Finally, it is noted that the dielectric-slab with the dielectric constant of 4.3 and thickness of 1.6 mm should be used to improve the transmission efficiency of the microstrip antenna with dual V-shaped slots operating in the interior environment.As the designed operating environment for the microstrip antenna with dual V-shaped slots locates in the interior water supply and drainage system, the paper makes a preliminary study for the adaptability of the antenna in the special environment. The writer analyzes the influence for the electromagnetic wave transmission of the microstrip antenna caused by the changing the layer spacing and environmental humidity. Electromagnetic simulation is applied for further discussion of the influence for the antenna caused by the layer spacing change. Also the humidity change can influence the dielectric constant of the concrete, then influencing the transmittivity of electromagnetic wave and the transmission performance for the antenna. Finally, the writer verifies that the design of the microstrip antenna with dual V-shaped slots can adapt to the operating environment and meet the design requirements.It is pointed out that as of the interior antenna design work, we should consider not only the various transmission performance of the antennas, but also their radiant influence on human bodies after long-term operation. The paper indicates that the electromagnetic simulation model of human body has been established by taking advantage of the selection models from Zubal human model system. When the microstrip antenna with dual V-shaped slots operates upon the human bodies, the writer uses XFDTD to calculate the distribution status of SAR value. After careful research of the SAR value status, analysis of the influence to human bodies by the antenna can be obtained. In summary, it is noted that the designed antenna has no harmful influence on human bodies, due to its low radiation in the interior operating environment. |
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