Design Of Omni-directional Broadband Antenna Array And Directional Dualband Antenna For WLAN

In recent years,with the development of wireless communication,wireless local area networks(WLAN)is widely used,the antenna working in WLAN band are also caused widespread research.And as the communication system becomes more complex,the requirements of the antenna are also increasing,so designing the antenna according to different application environment and which can save the spectrum has a certain theoretical value and practical significance.Therefore,this thesis presents two antennas that are applied in different directions of WLAN with broadband and multi-frequency characteristics.Firstly,this thesis presents an omni-directional broadband antenna array used in the 2.4 GHz band of WLAN.The unit antenna of the array uses microstrip printed structure with small size and can be easily to integrate.The patches are two sets of symmetrical oscillator that can achieve better broadband characteristics and the omni-directional radiation.The feed mode is coaxial,and the two vibrator arms of each group are printed on different sides of the dielectric substrate,avoiding the complicated feeding structures such as air jumper,which further reduces the size of the antenna.On this basis,an antenna array is designed and it is feeded by a four-part Wilkinson network.Then,this thesis also proposes an antenna working in the 2.4GHz and 5.8GHz bands of WLAN.The antenna uses the gap structure to achieve the characteristics of multi-frequency,and the feed mode is also using coaxial feed.At the same time,an annular slot strip line is introduced between the two feed points of the antenna,and the port isolation of the antenna can be better increased by optimizing the width and position of the annular gap.The antenna uses the floor as a reflector,realizing directional radiation,and the gain of the antenna is also improved.In this thesis,the theoretical design and simulation software optimization design are combined well.First of all,the HFSS software is used for modeling and simulation,and then the antenna's parameters were optimized and selected.Finally,the antennas are made according to the optimization results and the characters are measured.The test results show that the design of the two antennas basically meet the actual application requirements.