Research Of Microstrip Antenna Array For Short-range Radar

As for the design of Electronic Ticket Checking(ETC)system,a telecommunication antenna between vehicles and toll-gates should be designed in the first place.This communication antenna includes single transmitting-dual receiving antenna used to toll-gates and transmitting-receiving antenna used to vehicles.This paper centers on the research and design of the above two antenna arrays in the following aspects:Firstly,suitable dielectric substrate is determined,based on the analysis of the relation among the frequency bandwidth,radiation efficiency and dielectric substrate parameters of the microstrip patch.Then,the paper designs the embedded rectangle microstrip patch as the antenna array unit by HFSS.Secondly,in order to realize the directional diagram shape,this paper analyzes Chebyshev synthetic method,Villeneuve synthetic method and Variable scale optimization algorithm.This paper analyzes the features of the output port phase difference of the T-type microstrip power divider and then applies the features to unequal-spaced array factors.At last,the paper sets the unequal-spaced array factors as the objective function of variable scale optimization algorithm to do the beam forming.Thirdly,under limited space,transmitting-receiving array adopts loading bulkhead on both sides of the antenna to squeeze the half-power beam width of the antenna on E plane.Fourthly,fully uses of the above excitation amplitude phase distribution,three kinds of feed networks are designed.Feed network unit adopts the T-type form.In transmitting-receiving antenna array,the spaces among different output ports are set as g? so as to realize equal phase distribution,and lower the size of feed network in space.In single transmitting-dual receiving antenna array,through the control of the spaces among various output port to realize the output phases of various ports,the feed network required in microstrip beam forming array is designed.In the end,the feed network and antenna are cascaded,integrated simulation is optimized and the whole design meets the indexes of the microstrip antenna array.Lastly,the designed two microstrip antenna arrays are processed and tested.The test result shows that the microstrip antenna array designed in the paper meets the indexes.