Design And Research Of P-band Balance Limitter Amplifier

With the development of the international situation,the P band phased array radar system gets more and more applications.The microwave limited amplitude low noise amplifier(LNA)is an important part of the radar system receiving system.In the receiving state,the power limit of the leaked high-power signal can be limited and the output level is very small,which guarantees the limiter.The part of the LNA circuit will not burn down and the receiving system will not work.The limiting LNA module is the front-end device of the receiver system,and the sensitivity and dynamic range of the receiving system are mainly determined by its performance.In this paper,a high power P band limiting LNA is designed by using a balanced circuit structure.The basic principle of the limiting LNA is analyzed and the design process and the realization method of the practical circuit are given.The characteristics of PIN diode,which are used to make limiter of limiter LNA,are discussed.The heat effect of PIN tube and the method to solve the heat dissipation of PIN tube are introduced.The principle and circuit form of the limiter are discussed.Then the basic principle and design principle of the LNA of the receiving circuit of the LNA are studied and analyzed.The development process of a P band limiting LNA which can withstand 800 W power is mainly introduced.The realization scheme of the limiter amplifier is introduced in detail,and different schemes are analyzed and compared,and suitable circuit forms are selected.The selection method of PIN tube for designing limiter and the selection principle and simulation design process of LNA are presented in the paper.Finally,the assembly process and index test method of the whole circuit of the actual limiting amplifier module are introduced.This paper adopts the integrated design method,combines the limiter and the LNA index,uses the balanced circuit structure to carry on the circuit module design,greatly improves the power bearing capacity and the performance index of the component,making the design product with high stability and reliability.The P band 800 W limited amplitude LNA module designed in this paper has been put into batch production,and has the characteristics of high yield and good consistency,which has been assembled in a national defense radar system.After more than 1500 hours of field application,the module has been proved to be stable and reliable.