| 5G(fifth-generation)mobile networks will use millimeter wave(mm Wave)bands for wireless communications,to provide unprecedented connectivity with high data rates,low latency and high device density.As an important pole of the wireless communication system,many researches have been conducted for mm Wave antenna,and gradually developed to the direction of low profile,integration and miniaturization.Among them,phased array antenna technology has attracted extensive attention due to its high directivity,wide bandwidth,wide Angle beam scanning and other characteristics.In order to achieve high-density interconnection(HDI)with RF modules,designing phased array antenna by multi-layer printed circuit board(PCB)is a good solution,especially in recent years more popular Antenna-in-Package(Ai P)technology.But when using multi-layer PCB to design antenna or to build Ai P model,there are a series of electromagnetic interference(EMI)problems,which are worth studying.In addition,there will be very strong coupling between the antenna units,which will directly affect the performance of the antenna and bring large electromagnetic interference to the radiation of the antenna.The main research contents of this dissertation have the following two aspects.(1)The research of plate level electromagnetic compatibility for multilayer millimeter wave antenna.The microstrip antenna unit with operating frequency between 25 GHz and 27 GHz is designed,and the influence of multilayer PCB on the antenna is pointed out.An equivalent circuit is established for EMC analysis,and a SICL structure is further proposed to load the substrate in the multi-layer structure antenna,so that the antenna can maintain good characteristics in any layer of PCB.Finally,the four-layer plate antenna and eight-layer plate antenna are designed,and the simulation results and the measured results after plate making are obtained,and a good match is obtained,which proves the feasibility of SICL in practical engineering application.(2)Design of high isolation millimeter wave antenna based on SICL structure.The coupling between array elements of MMW patch antenna is studied and analyzed,including the antenna of different plate layers.By introducing the Friis transmission formula of the two-dimensional surface wave transmission equation,the coupling characteristics between the two elements of the microstrip patch antenna array in the low frequency band and the millimeter wave band were simulated and analyzed,and the mutual coupling effect was studied qualitatively and quantitatively,so as to provide reference and standard for the design of the millimeter wave antenna with high isolation degree.Then,the influence of SICL structure loading on the isolation degree of array elements of the multilayer antenna was given,and the beam scanning pattern characteristics of different antenna layers were studied and analyzed,and the role of SICL structure in the multilayer antenna was comprehensively analyzed. |
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