Thz Photonic Crystal Design Of The Antenna And Thz Wave Attenuation Characteristics In Plasma Research

Becase THz wave is between visible light and microwave; it has particular characteristics in many aspects. Besides its wavelength is short, the size is designed small, and it is suitable to security detection, Satellite Communications, medical research.When the aircraft flies with high speed, it will produce plasma on its surface, because the air and heat resistant material are ionized. Therefore, the electromagnetic wave is serious attenuation or cannot pass when getting through it, and it cannot communicate. This phenomenon is called blackout. According to its dispersion characteristics, the high frequency electromagnetic wave is easier to get through. The frequency of THz wave is higher compared with that of microwave, so it penetrates the plasma easier. We mainly consider using the THz wave to solve the problems of blackout.In this article, the causes of the blackout are introduced, and some solutions are analyzed. And we propose to solve the blackout by increasing the frequency of electromagnetic wave and developing the THz wave. Thereafter, the concept of photonic crystals is introduced, photonic bandgap theory is analyzed. We solved the radiation field of ordinary horn antenna and designed a horn antenna (f=300GHz). The power of Terahertz Sources is very small, so we improve gain of antenna and attain a better direction of antenna as best as we can. We can restrain surface wave by using the bandgap of photonic crystals, improving the performances of the antenna. The horn antenna is designed by using the photonic crystals, and it is simulated by using CST software. The frequency of THz antenna is 300GHz, and the gain of THz antenna gain is 17.6dB. Compared with the traditional antenna, the gain is increased, main lobe narrowed, antical lobe weakened, and the directivity improved. Finally, the Principle of interaction between electromagnetic wave and plasma is analyzed. By using the numerical analysis and simulation, we research the attenuation of THz wave in the plasma. Establish a physical model about interaction between THz wave and plasma. The results proved that THz wave is feasible to solve the problem of blackout.