Research And Application Of Optically Transparent Directional Radiation Antenna

With the development of modern communication systems, wireless communications systems put forward higher requirements on the antenna performance, such as multi-band, miniaturization, optically transparency,directional radiation, aesthetics and so on. In order to meet these design requirements, the design of antenna becomes more difficult. The study of multi-band and miniaturization are already mature, but the study of directional radiation characteristics of the optically transparent antenna is still in its infancy. Optically transparent directional radiation antenna can be used in the terminal antenna, vehicle antenna, satellite antenna and many other communication scenarios, it achieves the directional radiation performance of the antenna and is able to get good aesthetics and stealth performance at the same time. it is a very promising antenna type.The main purpose of this paper is to design an optically transparent directional radiation antenna, which can be integrated with the automotive grade glass for the vehicle networking scene (frequency band during 5725-5850MHz ). In this paper, the research status and significance of the optical transparent antenna are introduced firstly, and the prospect and advantage of the optical transparent antenna are introduced too. Then, a brief introduction is given to the show the radiation characteristics of the antenna, and two schemes are proposed to realize the directional radiation performance of the optical transparent antenna: the electric dipole and magnetic dipole directional radiation antenna structure and the microstrip directional radiation antenna structure, Electric dipole and magnetic dipole are both made of Indium Tin Oxide film, and are placed in the same plane, when they are excited at the same time, the directional radiation performance are achieved. The radiational pattern of the electric dipoles and magnetic dipoles in the E-and H-plane are complementary (The E-plane pattern of electric dipole is 8 type, H-plane pattern is 0 type, and the E-plane pattern of magnetic dipole is 0 type, H-plane pattern is 8 type ), So that they are compensate to each other in the E-plane and H-plane. The directional radiation direction of this antenna structure is parallel to the plane where the antenna is located, which limits the application of this antenna structure.Therefore, this paper proposes a directional radiation antenna based on microstrip antenna structure. The patch of this antenna are made of Indium Tin Oxide film, and the substrate is low dielectric constant borosilicate glass which is transparent too, so the antenna are optically transparent. The band-stop frequency selective surface can totally reflect the electromagnetic wave which frequency is in the stop-band of frequency selective surface. So using the band stop frequency selective surface to replace the ground of microstrip antenna can achieve both transparency and can directional radiation, and radiation direction of the antenna is perpendicular to the plane where the antenna is located, and the radiation performance of this antenna structure is good.In this paper, two types of directional radiation transparent antenna are simulated in the CST electromagnetic simulation software, and the best results are obtained. Then, the two antennas are fabricated and tested.Optically transparency and directional radiation characteristics are achieved.