Study On Fixed Beam High Gain Multiple Resonant Sector Patch Antenna Array

For the antenna applied in wireless communication systems such as base stations,radars,and microwave remote transmission,it is generally expected that the antenna only transmit and receive electromagnetic waves in a direction.While in other directions,it is expected that less electromagnetic waves transmitted and received by the antenna.Hence,high directional and gain antenna is extremely important in the modern wireless communication system.The antenna array can effectively achieve a high gain characteristic,but the gain for four-element antenna array is generally 14±2 d Bi,and the array usually has a high profile and complicated structure.In this thesis,a sector patch antenna with simple structure is employed to implement high gain antenna arrays.The main content of this thesis is organized as follows:1.According to the eigenmode theory,dual-resonant wideband sector patch antennas with flared angles of 270° and 300° are designed.Then antenna elements are employed to implement fourelement high gain fixed-beam E-plane and H-plane arrays.An improved zigzag topology is employed in the arrays.Ansoft HFSS simulation software is used to analysis the element spacing.Finally,antenna array prototypes with an operating frequency of 3.25 GHz are fabricated.Four-way Wilkinson power dividers serve as the feeding networks for all arrays.All feeding networks are fabricated on F4 B substrate with the relative dielectric constant of 2.65.The array prototypes are measured by employing an Agilent's N5230 A vector network analyzer and a Satimo's Starlab near-field antenna measurement system.The simulated and measured results agree well,which proves the high gain characteristic of the antenna arrays.2.The patch antenna element with a flared angle of 270° is employed to implement a fourelement planar antenna array,a diamond topology is employed to reduce the sidelobe level.MATLAB simulation software is used to determine the relationship between the grating lobe level and the element spacing,then an appropriate element spacing is selected.Other parameters of the antenna arrays are optimized by HFSS software.Finally,the antenna array is fabricated and measured,the measured results are in good agreement with the simulation results.This high gain four-element planar antenna array with extremely low profile further proves that the dual-resonant sector patch antenna element is proper for implementing antenna array.3.On the basis of the four-element linear array antenna,the antenna array with beam scanning characteristic is further researched.A four-element linear beam scanning antenna array is designed.HFSS software is used to simulate the discrete scanning.The maximum scanning angle can reach to 55-degree.The effectiveness of antenna array implemented by sector antenna element is fully verified.