K-band Eight-beam Active Phased Array Receiver Component Design

With the continuous development of science and technology,active phased array plays an important role in many military fields,such as satellite,shipborne and airborne.Among them,RF receiving component is the core part of active phased array,and broadband and multi beam are becoming the important development direction of receiving components.In this paper,the design and implementation of the K-band eight beam active phased array receiving component is completed by using the technology of microwave multi chip module(MMCM),combined with microwave monolithic integrated circuit(MMIC)and microwave multilayer board technology.Firstly,this paper summarizes the development status of multi beam phased array receiver at home and abroad by fully investigating the relevant literature at home and abroad.The theory and technology of the eight beam receiver module designed in this paper are introduced in detail,including the theory of active phased array and microwave multi chip module technology.At the same time,by comparing the microwave multilayer board technology and LTCC technology,and after understanding the microwave multilayer board processing technology and specifications,we choose it as the board of this circuit design.Secondly,after analyzing the design index,this paper makes a detailed scheme design for the K-band eight beam phased array receiver module,including single channel link design and level allocation,and uses ADS simulation software to simulate and evaluate some important parameters of the receiver module,including link gain,noise figure and P1 d B.On the basis of microwave multi-layer board,considering the performance and cost factors of different boards,the hybrid structure of Rogers4350 and FR4 is determined.At the same time,the microstrip line,vertical interconnection structure and bonding alloy wire are modeled and analyzed in HFSS simulation software based on the laminated structure,which makes them have good transmission characteristics in K-band.For the important vertical interconnection structure,the vertical strip structure and two kinds of vertical through-hole transition structure are modeled and simulated respectively.After comparing the simulation results,the vertical through-hole transition structure with larger return loss and wider bandwidth is selected.The test results show that the insertion loss is less than 2.5d B and the return loss is less than 25 d B in the range of 19-21 GHz.Based on the analysis of the above transition structure,and considering the complex routing and cross transmission problems of the eight beam synthesis network,the whole eight beam synthesis network is gradually modeled and simulated by unit simulation,the whole eight beam synthesis network is modeled and simulated by unit simulation.Within 19-21 GHz,the insertion loss of each port is less than 0.5d B,the return loss is more than 20 d B,and the isolation of each port is more than 35 d B.Finally,according to the system design scheme,the layout design of the RF circuit and beam control circuit of the eight beam active phased array receiver module and the structure design of the whole machine are completed.The whole machine is assembled through the micro assembly process,and the final size of the whole machine is about 176mm×72mm×19mm.The test results show that in the 19-21 GHz frequency band,the phase-shifting accuracy is within 4°,the channel gain is greater than 53 d B,the gain flatness is within ±1d B,the attenuation accuracy is within 0.24 d B,and the noise figure is within 3.4d B,which meets the index requirements.