Design Of Multi-Frequency Antenna For Satellite Navigation System

With the development of satellite navigation, many countries have had their own satellite navigation. Because of the limitation of the independence system satellite constellation, service precision, reliability, security and availability provided by the system can not be guaranteed, the research of the multi-mode satellite navigation system is attached importance to. Antenna is a very important unit of the satellite navigation system. The performance of the receiver is affected by it partly. The antenna with the character of circularly polarized, working at multi-frequency and wide band is paid attention to for the multi-mode satellite navigation system. In this paper, the single frequency antennas, dual-frequency antennas and multi-frequency antenna are designed for the multi-mode working at multi-frequency. These antennas are simulated and optimized by applying the numerical method of electromagnetic field. The details of this paper can be introduced as follows:Quadrifilar helix antenna (QHA) and microstrip antenna are widely used in satellite navigation system. The academic methods of these antennas are introduced firstly. Secondly, the single frequency, dual-frequency and multi-frequency circularly polarized (CP) microstrip antennas are designed according to the theory. In order to make the single frequency microstrip antennas have the character of CP, the methods of single feed and dual feeds are applied. And the multi-frequency CP microstrip antennas are fed by dual signals. The air-gap layer between two patches is get rid of in order to make the antenna compact and easy to fabricate. Lastly, the single frequency QHA, the dual frequency closed QHA and multi-arm QHA are designed according to the theory. Simultaneously, the feeding networks of the single frequency and dual frequency QHAs are designed, too. These antennas are simulated and optimized by the software of ANSOFT HFSS that is based on the Finite Element Method (FEM). The single frequency CP microstrip antennas and QHAs working at 1.27GHz and 1.575GHz respectively are designed. And the dual frequency CP microstrip antennas and QHAs working at above- mentioned frequency are designed, too. In this paper, the triple-frequency CP microstrip antenna works at 1.27GHz, 1.575GHz and 2.5GHz. These antennas could be used in the satellite navigation system.