The Study Of Tightly Coupled Antenna Array

Untra-wideband phased array antenna is widely used in communication systems.The traditional way of designing a phased array antenna needs a broadband antenna unit and the coupling effects among the array elements is greatly influenced the band of array.According to the traditional designing idea is difficult to expand the antenna array bandwidth.This paper introduce a way based on tight coupling theory for designing array antenna.This method uses the strong coupling between cells and breaks the limitations of the inter-unit coupling for array bandwidth.First,this paper introduces the main forms of traditional broadband antenna.Second,the development history and research results of tightly coupling antenna array are introduced.Finally,based on the theory of antenna array,combined with the literature,the ultra-wideband tightly coupled antenna array is designed.The thesis mainly contains design,simulation and processing of ultra-Wideband tightly coupled antenna arrays.The design process includes periodic units,feed balun,tightly coupled antenna arrays.First of all,a unit with 10:1 bandwidth is designed,the unit successfully uses the resistive frequency select surface to eliminate the short circuit caused by the reflection of the floor.Secondly,According to the equivalent circuit of balun,the balun can work well in the working band of the antenna,using the branch match to achieve the impedance of balun and antenna matching.The units are arranged in 8 × 8 array with short circuit units.Considering the truncation effect,the short-circuiting units are added an the edge of the array.The simulation results show that the array has 10:1 bandwidth,and in the ?? 45 range of airspace to achieve beam scanning.However,due to the large size of the vertical,the grating lobe appears at the maximum scanning angle point.The antenna array processing into a physical,RFSS materials are conductive glass.In this paper,we use the differential phase delay line as the phase system,using the coaxial line with different length to realize the phase difference.the final measured results and simulation results are basically the same.At the end of this thesis,a dipole form is proposed which increases the coupling area between the units,and coaxial feed is used to obtain the 15.4:1 bandwidth.