Design And Implemetation Of High Integration Digital Receiver

With the rapid development of monolithic microwave integrated circuit,micro-assembly technology,AD sampling circuit,large-scale programmable logic circuit and multi-channel digital receiving technology,digital receivers have almost completely replaced analog receivers and become the main direction of current receiver technology development.In recent years,the development of phased array radar technology in China is also changing with each passing day.Especially the digital array technology is becoming more and more mature.Multichannel receivers have strict requirements on inter-channel characteristics such as channel isolation,multi-channel amplitude and phase characteristics,multi-channel synchronization,etc.With the rapid increase of the number of receiver equipment,the requirement for the volume and cost of receiver system is becoming more and more stringent.Based on the literature,this paper analyses and summarizes the development status of multi-channel digital receiver from the working principle,replaceable RF module,multi-channel reconfigurable IF sampling receiver and so on.In this paper,a high integration digital receiver based on MMIC and FPGA technology is designed to meet the requirements of phased array radar system.The research work of this subject is mainly divided into the following two aspects:(1)The design of the hardware circuit of the system is carried out.The hardware circuit includes the analysis and design of secondary mixer circuit,local oscillator power divider circuit,VGA,AD sampling circuit,FPGA,power supply,clock circuit and so on.The RF circuit design based on microwave monolithic chip and the digital down conversion design based on FPGA are adopted,which greatly improves the system integration.(2)The design of system software was carried out.Parametric design can change FIR filter coefficients,data extraction rate and whether to use CIC filter according to different working modes.It can dynamically control the frequency and phase of NCO.When realizing FIR,the method of increasing working frequency and multiplexing DSP is adopted to reduce the usage of DSP multiplier.Aiming at the problem of multi-channel synchronization,the automatic anti-collision edge of clock synchronization is designed in the software.In this paper,aiming at the performance index of multi-channel digital receiver and the characteristics of multi-channel and multi-frequency points,an automatic test platform is designed,and the technical index of digital receiver is tested and verified in detail,which meets the design requirements.