Key Technology Of Protection For RF Circuit From High Power Microwave

A research about the damage effect and protection for high power microwave ispresented in this thesis.Firstly, a research about the effect of active circuit under high power and itsprotection from high power microwave is carried out. This paper takes the low noiseamplifier, which is the key and vulnerable component in a receiver, as an example tocarry on the research. Based on a proposed experimental platform for the front doorinjection, the damage threshold of the low noise amplifier is obtained according to theperformance variation of low noise amplifier. In order to protect the low noise amplifierfrom high power microwave, a novel high power microwave limiter is designed usingPIN diode, which has low insertion loss、high power durability and low limiting level,and the effectiveness of front door protection is validated through experiment. Based onthe dual band dual path coupling method, a high power measurement platform isestablished in the purpose of measuring the performance of the designed limiter.Besides, a dual channel limiting duplexer is designed, which is used to ensure thecommunication when the receiver is under attack by HPM. Furthermore, the shieldingeffectiveness of incomplete shielded enclosure is analyzed using simulation softwareHFSS. After that, the method of hybrid analysis technique is used to study the highpower microwave effect of back door injection to a low noise amplifier under anincomplete shielded enclosure.Novel method and theoretical analysis is introduced in the design of passivecircuits for high power application. A novel Gysel power divider based on the patchtype structure is presented, which possesses broad bandwidth、small physical occupationand arbitrary power division. No narrow microstrip line is used in the power divider,which makes it possible for high power application. Finally, based on a theoreticalanalysis, a high power divider with low insertion loss is designed. Its unequal powersplitting can be realized just change the electrical length without using high impendenceline, which makes it convenient for the design and application.The research methods as well as the conclusions and achievements obtained in thisthesis can not only be useful in the research about the effect of high power microwave,but also be a reference to the application of high power microwave.