Design Of Dual-Polarized Array Antenna For Ocean Salinity Detection

In recent years, with the widespread applications of the wireless communication systems in various fields, the information technology is also developing rapidly. As the key components in the systems, the performance of the antennas is directly related to the quality of the whole system. Therefore, a higher demand of designing antenna is put forward. The development of the antennas is mainly towards ultra-wideband,miniaturization, multi-polarization. Due to the advantages of polarization diversity,frequency multiplexing and transceiver integration, the design of the dual-polarized antennas becomes a hot topic now. Based on the requirements of the satellite which is used for the detection of ocean salinity, a dual-polarized antenna is produced in the paper, and according to the project demands the antenna array simulation and optimization is also discussed. This paper includes following several aspects of the work:1. According to technical requirements two kind of dual-polarized antenna units are introduced in the thesis. The first kind is an H-shaped aperture-coupled microstrip antenna of which operating band is effectively broadened by adding a parasitic patch. With the help of the high-frequency electromagnetic simulation software Ansoft HFSS, we simulated the antenna and a 50 d B greater isolation is obtained within the bandwidth, and meanwhile the level of the cross-polarization is less than-25 d B, which meets the design requirements;The second is a cup-like microstrip antenna. The radiation patch is fed by a 1to 2Wilkinson equal amplitude inverting network, of which the level of the cross-polarization is limited effectively. After simulation a 48.5d B greater isolation is achieved, while the antenna unit prototype is fabricated. The measured and simulated results show good agreements.2. Taking into accounts the factors including temperature, humidity etc. which have significance influence on the performance of antennas, so the air microstrip antenna is selected as the radiation element of the array antenna. The array is simulated and optimized under the whole system. Then considering the influence of the performance of the antenna carrying metal plate, especially the influence on the radiation pattern of the unit, several solutions are taken to improve the performance by adding ridges based on the results which meet the project requirements.3. According to the designed array, the antenna is processed and tested, test results are in good agreements with the simulation results, which verifies the correctness of the design.At last, the full text is summarized, the deficiencies in this paper are pointed out and the direction for the next step of work is also indicated.