The X-band Radar Receiver For The Optimization Design Of The Key Components

With the fast development of ship industry, there must be a huge market for thenavigation electronic equipment on boat. According to a survey, Chinese marine radarcompany is still lacking of competitive power against the foreign company who ownsthe key of radar technology. Through the magnetron pulse radar has been widely used,it exposes some obvious weak points such as the frequency shifting, the receiverfront’s damage, the small dynamic range and the lower reliability. Focus on theseproblems, a line of research on radar receiver has been done in this paper, in order toimprove the system’s performance and make Chinese radar more competitive.Based on the principle of radar receiver, the method of optimizing and designingis introduced at first, and then the work frequency and super heterodyne structure areselected. After analyzing all of the action parameters, the goals of optimization havebeen determined. Further study continues while receiver being divided into three parts:RF front, IF signal processor and micro-control unit. To protect the front against thehigh transmit power, a TR switch and limiter hybrid circuit is designed. Meanwhile alow noise amplifier before mixer can help system control the noise and add the signalgain. Next there is a RF front performance test to indicate the function. Instead of sometraditional ways (AGC or STC) which can expand the dynamic range by cutting downthe detection ability, logarithm receiver is used here. Because of the magnetronfrequency shifting who affect the stability lot, an analog-digital AFC module controlledby a chip is also designed and its rest detuning is improved more from the commonAFC. Additionally, some codes for the serial port communication between receiver andDSP are completed to get the whole system connection possible.Besides, considering the experiment condition of high cost and large field, a radarback-wave generator has been made to replace the transmitter and antenna in receivertest. On the optimized test bench, the receiver designed in the dissertation is estimated.At last, all these work above are proved helpful to improve the performance of receiver,by analyzing the detection images of radar system which is fixed on the ship.