Research On High Performance Microstrip Antenna Technology Based On Planar Periodic Structure

With the rapid development of modern communication,antenna has been widely used in wireless communication,mobile communication,satellite communication,electronic warfare,radar and so on.Microstrip antenna has the characteristics of small volume,low profile and light weight,It can integrate with microwave RF circuits,making it more widely applied.This thesis combines the specific project indicators,focusing on the "broadband miniaturization" of the microstrip antenna,it can be used as UAV image transmission communication antenna,working in the 5GHz WIFI band.First of all,a full study has been conducted on various techniques for widening the antenna width and reducing the antenna size at home and abroad.The techniques for widening the antenna width include: increasing the thickness of the dielectric substrate,using a dielectric substrate with a low dielectric constant,using a dielectric substrate of a special material,adding an impedance matching network,short-circuit pin loading,using electromagnetic coupling feed,gap loading,and using multiple layers Structure,etc.However,these broadband technologies all have certain limitations,which will lead to an increase in antenna bandwidth but reduce other antenna performance indicators.Miniaturization technologies include: surface grooving,the use of special-shaped radiation patches,short-circuit loading,and the use of high dielectric constant dielectric substrates.Similarly,these miniaturization technologies also have certain limitations,and will also lead to an decrease in antenna size,but reduce other antenna performance indicators.In order to solve the difficulties faced by the current broadband miniaturized antennas,this thesis is based on the analysis of currently used broadband miniaturized antenna technologies at home and abroad,For the first time,the method of “loading parasitic patches” and “loading RIS impedance surfaces” is proposed to realize ultrawideband and miniaturization characteristics of microstrip antennas.Among them,the loaded parasitic patch can effectively improve the impedance bandwidth of the microstrip antenna and further increase the gain of the antenna.This is because the induced current on the parasitic patch also radiates electromagnetic energy to the outside.The loaded parasitic patches are arranged in a blank area around the main resonance unit of the antenna and do not increase the size of the antenna.The loading of the RIS impedance surface is mainly used to reduce the size of the microstrip antenna.Compared with the traditional antenna miniaturization method,the effective radiation aperture of the microstrip antenna is not reduced when the antenna is miniaturized using the impedance surface technology.Instead,the radiation gain is higher.This antenna can meet the user requirements,the antenna can work effectively in the 5GHz WIFI band,the transverse dimension of the antenna is only 32 mm ? 32 mm,the profile height is 2.037 mm,a small structural size.the voltage standing wave ratio in the entire working frequency band is less than 2,with higher gain and radiation front-to-back ratio,the antenna can carry out stable image information transmission.