Analysis And Research Of The Two-dimensional Multi-beam Antenna Based On Rotman Lens

Multi-beam antenna array is widely applied in military and civil fields,such as radar,electronic countermeasure,electronic surveillance,high data rate wireless communications,local point-to-multipoint mobile communications,millimeter-wave imaging and so on.At present,multi-beam forming network feeding array antenna and phased array system are two main ways to form multi-beam array antenna.However,phased array system requires a large number of transmitter and receiver modules,which are high cost;multi-beam forming network has the remarkable advantages of low cost while achieving multi-beam antenna.As one of the most commonly used multi-beam forming network,Rotman lens has the advantages of wide band,low cost and so on.Therefore,Rotman lens has caused many researchers at home and abroad researching interests.To achieve two-dimensional multi-beam scanning is the increasingly strong demand of a vast number in practical applications,but the study about two-dimensional multi-beam array antenna based on Rotman lens is few.Therefore,the theory,structure design and experimental research of the two-dimensional multi-beam antenna based on Rotman lens is now become essential and urgent.At the same time,in order to realize compact structure,the miniaturization of Rotman lens is also an important research field.The main contents of this paper are as follows:Firstly,the basic principle and background of array antenna and multi-beam array antenna are introduced in detail,and the main types of multi-beam forming network and their corresponding advantages and disadvantages are elaborated.Then,the current research status and practical application of one-dimensional and two-dimensional Rotman lens are respectively expounded in detail,and the extensive research and practical application of Rotman lens as multi-beam forming network are demonstrated.Secondly,since the two-dimensional lens multi-beam network designed in this paper is based on one-dimensional Rotman lens and R-kR lens(a special kind of Rotman lens),and therefore the basic principles,formula derivation and design method of Rotman lens and R-kR lens are respectively introduced.At the same time,the principle,advantages and disadvantages of the three methods of two-dimensional Rotman lens multi-beam forming network are described.By comparative analysis,the stacked lens is selected.Then,based on the design and analysis of two-dimensional substrate integrated waveguide stacked Rotman lens,one-dimensional substrate integrated waveguide Rotman lens and R-kR lens are designed.What's more,two ways of transformation connection structure of the two-dimensional stacked lens are studied;the microstrip and the parallel two-wire structure are designed respectively,and the latter works better by the comparison of simulation and measured results.The two-dimensional stacked Rotman lens multi-beam array antenna is manufactured,tested,and the experimental results is analyzed.Finally,carrying out the miniaturization of microstrip Rotman lens,because the transmission phase-shift line of the traditional microstrip Rotman lens is too long.In order to realize the miniaturization,the composite right and left hand transmission line(CRLH-TLs)is used to carry out the phase shifting.Compared the performance of the Rotman lens based on the CRLH-TLs with the original lens,it is proved that the miniaturization of the microstrip Rotman lens can be effectively realized by this method within the certain bandwidth.