Investigation Of Plasma Antenna And RF Properties With FDTD

Of the three methods of predicting electromagnetic effects—experiment, analysis, and computation—computation is the newest and fastest-growing approach. Of the many approaches to electromagnetic computation, including method of moments, finite difference time domain, finite element, geometric theory diffraction, and physical optics, the finite difference time domain (FDTD) technique is applicable to the widest range of problems.Researchers have presented the proposal of using high-density plasma (approximately 10¹²/cm³) as the conductor in an RF antenna and have paid attention to the concept of plasma antenna for years. Characteristics of the plasma antenna largely depend on the behavior of an electromagnetic wave propagating in plasma. However, few analytical solutions of the plasma antenna have been carried out because the permittivity of plasma varies significantly with frequency. With rapid growth of computation speed, the FDTD method offers an accurate way for simulating the interactions between plasma medium and radio wave, also predicting the characteristics of such antenna. According to the numerical results of antenna's input impedance, radiation pattern and efficiency, in contrast to the conventional copper antenna, the plasma antenna has the advantages of broadband, dynamically reconfigurable characteristics.FDTD method is also effective in investigating the problems of Plasma mirror based radar antenna and Re-entry communication blackout. Reflectivity and transmissivity are computed with the variations of plasma parameters, including plasma frequency, collision frequency and plasma density distribution, which make the theoretical guidance of further experiments and applications.