Research Of Communication Antenna Arrays And Feed Networks At S Band

At the beginning of the 21 st century,tremendous changes have taken place in science and technology.The wireless communication,which is closely related to people's life,has developed rapidly in recent years.At present,the wireless communication has become one of the most promising and active fields and the antenna plays an important role in the system.In the early stage of development,due to the lack of the theory of electromagnetic wave and antenna,the antenna commonly worked in a single form and single polarization mode.With further studying by researchers,more and more forms of antenna are proposed.In particularly,the circularly polarized antenna has been paid more attention for good performances.Moreover,with the development of array antennas' theory,array antennas have drawn more attention from public.Now,array antennas are widely used in the communication system due to their special features such as high gain,anti-interference,high direction and electronic beam scanning.As an important part of the feeding network,power dividers also occupy an important position in the antenna system.Based on the theory of array antennas and power dividers,several array antennas and a power divider are researched and designed in this paper.The main contents are as follows:1.A linear array antenna with four elements in S band is designed.The planar spiral antenna is used as an element.The element rotation technique is used to reduce the axial ratio of the array.Considering improving the gain of the array,sidelobe suppressing,reducing the coupling and the size,the unit spacing and overall size are simulated and optimized.The antenna is produced and test results basically meet all requirements.2.A planar array antenna with four elements in S band is designed.The planar spiral antenna is used as an element.The element rotates around the center of the plane as 90 degrees.This structure has the advantage of reducing axial ratio.By optimizing elements spacing to meet all requirements,the antenna is produced.Test results basically meet the requirements and the axial ratio of this planar array is better than the above linear array.3.A linear array antenna with four elements in UHF band is designed.The antenna element is a circular polarization antenna.The vacuum is used as the substrate of the antenna. Through the adjustment and optimization of the array,higher antenna gain is achieved and the axial ratio is well.4.A power divider in S band is designed.The power divider is cascaded by a coupler and a power divider.The approach of cascading can not only increase the power divider's working bandwidth but also increase the width of the microstrip.The power divider is manufactured and the test results meet all requirements.