Design And Implementation Of OFDM Radar RF Transceiver In X-band

With the rapid development of electronic technology and navigation industry,radar is widely used in navigation,transportation and exploration.Radar based on Orthogonal Frequency Division Multiplexing(OFDM)system has become a research hotspot due to its advantages of flexible waveform design,high range resolution,high doppler resolution,multiple carrier frequencies,high frequency band utilization,robust ability to resist multipath interference and the convenience to integrate.One of the most typical applications of OFDM radar in the civilian field is ship navigation.Ship navigation radars have the functions of narrow-gauging piloting,positioning,vessel avoidance,and night navigation,effectively guaranteeing the safety of ships navigation.In order to meet the demand of near-target detection for navigation operations,this thesis studies the OFDM navigation radar,analyzes the basic principles of OFDM navigation radar,and proposes an overall design scheme for an OFDM navigation radar with an X-band(9.3GHz-9.4GHz)75MHz bandwidth,and then,completes hardware implementation and experimental verification.The main work of this article is listed as follows:First of all,the basic principle of OFDM radar is analyzed.According to the application scenario and related performance requirements of OFDM navigation radar,the RF front-end performance index of the system is proposed and the overall scheme of the system is designed.The main application chip selection is completed according to the system scheme.The feasibility analysis of the major modules is conducted.Secondly,the design of hardware circuit and implementation of the RF front-end of OFDM navigation radar are carried out.According to the idea of modularization,the entire system is divided into five modules: power module,control module,clock module,transmit link and receive link,including digital-to-analog conversion,IF filtering,IF amplification,up-conversion,and RF amplification.Radio frequency filtering in the transmit link and RF filtering,low-noise amplification,down-conversion,and intermediate-frequency filter amplification in the receive link.Each sub-function module are designed and implemented respectively,and then the welding and hardware debugging is completed.Finally,functional tests were performed on the OFDM radar RF front-end,and clock signals,local oscillator frequency source signals,target emission signals,and system tests were performed.The test results show that this design scheme basically meets the design requirements of the RF front end of OFDM navigation radar.