Development Of Frequency Hopping And Self-tuning Signal Processor

With the development of modern radar industry,there are more and more kinds of radar transmitters,magnetron transmitter is one of them.Although it has the advantages of high output power,high efficiency,small size,low working voltage,light weight and low cost,but it has a very serious disadvantage,that is,the frequency stability and phase stability are poor,if it is not processed,it will have a great impact on the back-end signal processing.In view of this,this paper studies the phenomenon of poor frequency stability of radar magnetron transmitter,and improves a high-precision instantaneous frequency measurement method based on phase estimation.In addition,how to quickly realize the frequency hopping function of magnetron transmitter is also studied.Finally,a frequency hopping self frequency adjusting signal processor is designed and developed based on the research results of these two points.It adopts the method of direct RF sampling,directly sampling the RF signal,and then uses the digital instantaneous frequency measurement method to realize the accurate measurement of the frequency of the magnetron transmitter,and drives the motor to implement the real-time accurate tracking in the tracking state.At the same time,the system parameter recovery is realized by using the circuit of low-power instantaneous power-off data recovery to save the abnormal power-off data.The design adopts FPGA hardware structure,which can better undertake the task of complex timing design and signal processing algorithm.A large number of practical tests on the whole radar show that the frequency hopping self-adjusting signal processing can effectively solve the problem of poor frequency stability of magnetron transmitter,and provide high-precision digital instantaneous frequency measurement function as well as fast and accurate frequency hopping function,the frequency measurement error is less than 5KHz under 40 d B signal-to-noise ratio,and the maximum frequency hopping time does not exceed 2 seconds.Under various complex environmental tests,the stability of the signal processor is verified,which shows that the content of this paper has good application?...