Broadband Reflectarrays Antenna

Reflectarray antenna has the advantages of small size, light weight, good radiation performance, and easy feed network, suitable for satellite communication. But it also has drawback of narrow bandwidth, can’t carry out large capacity data transmission. The focus of this paper is to improve the bandwidth of reflectarray antenna.Firstly, the broadband reflectarray element is studied, including the radiation principle of the reflectarray element and the method of extracting the phase shift curve using HFSS. On this basis, we design three forms broadband microstrip reflectarray antenna which are multi-resonant structure, respectively, wafer + ring structure, ring + ring structure, ring + monopole structure, the multi resonant structure can not only get smooth phase shift curve, but also can optimize broadband radiation characteristics.Then, we design reflectarray antenna, including the phase compensation method and the specific design process of antenna. Three kinds of broadband reflectarray antenna are designed based on three kinds of broadband reflectarray element. The working bandwidth of the antenna is two times higher than ordinary reflectarray antenna. The antenna tests were carried out on the wafer + ring antenna which results show that this form of reflectarray antenna has broadband radiation characteristics.At last, a broadband dielectric reflectarray which reflectarray element is dielectric is designed. The results of the simulation show that the dielectric reflectarray has a wide working bandwidth and can achieve broadband radiation.