High Efficiency Transmitarray Antenna Research

As rapid developing of modern Radar, wireless communication and electronic countermeasure and continuously upgrading of electronic equipment, the desire for high performance antenna becomes higher than before. Transmitarray antenna have many advantages such as low profile, light weight, simple feed, flexible and easy control of beam and low cost, etc, has attracted more and more attention and became an important research direction of antenna domain. The dissertation mainly makes research on transmitarray antenna and transmission characteristic of transmission element, analytical expression of transmitarray radiation field is derived base on array theory, and transmission characteristic of single layer and multilayer transmission elements is theoretical calculated and analyzed by microwave network theory, some research work is accomplished with the goal of high efficiency and terahertz transmitarray, the main contributions of this work are listed as follows:1. Transmission characteristic of single layer and multilayer transmission elements with different permittivity and different separations between layers is theoretical calculated by microwave network theory, the relationships between transmission phase and transmission magnitude are analyzed and reached the following conclusion: for vertical incidence, at certain transmission magnitude, the maximum transmission phase range is determined based on the number of layers, substrate permittivity, and layer separations. Single layer and multilayer elements with different shapes are simulated and the simulation results are compared to theoretical calculated results to confirm the conclusion.2. A novel double split rings slot element with low transmission loss and insensitivity to the incidence angle of electric field is presented, and a transmitarray antenna composed of the elements is designed, manufactured and tested at Ku band. The measured radiation efficiency and aperture efficiency are higher than the other types of transmitarray antenna, is a high efficiency transmitarray antenna. Because the transmitarray is manufactured by conductor layers, which can bear changes in extreme outer space temperature compared with the dielectric substrates, is very suitable for aerospace application.3. A phase compensation method base on real phase of the feed radiation field is presented, which could efficiently reduce the phase error introduced by the instability of horn’s phase center.4. A fabrication process of terahertz transmitarray antenna is presented base on UV-LIGA and DRIE techniques. A terahertz transmitarray antenna working at 340 GHz is designed and fabricated. The measured results show that the radiation pattern of terahertz transmitarray prototype could be well defined with narrow beam, low sidelobe, and very good agreement of the main beam between E-plane and H-plane, indicate that is very suitable for terahertz technology.