Development Of Wideband Reconnaissance Receiver Front End

The electromagnetic information in modern electronic warfare becomes more and more complicated.In the electronic warfare between the enemy and the enemy,the reconnaissance and anti-reconnaissance of the electromagnetic spectrum is becoming increasingly fierce.The receiver in the electronic warfare as a core part is changing,and it is constantly moving toward complexity,miniaturization,and digitization.In order to meet the needs of the military,the technical indicators of the reconnaissance receiver in the electronic warfare are also oriented towards the development of broadband,high sensitivity,large dynamic range,and high real-time performance.This article firstly introduces the related research background and domestic development trends at home and abroad.;then it briefly explains the basic structure and main indicators of the receiver,and analyzes the structure of commonly used receivers;Then the overall general design scheme of the receiver is given,at the same time,the design and implementation of the receiver are introduced in detail,mainly includes the radio frequency front end,host computer and slave computer,and digital frequency spectrum analysis.Finally,the entire receiver is tested and analyzed.The RF front-end part mainly introduces the design of some key modules,including switching circuits,pre-selection and amplification circuits,gain control circuits,local oscillator circuits,up-conversion circuits,demodulation circuits,baseband amplification and filter circuits,etc.,and then gives detailed analysis on the basis of design schematics.The control part mainly includes the FPGA control circuit of the slave computer and host computer.The part of FPGA control circuit mainly designs serial communication modules and related chip control modules,such as phase-locked loop control modules,attenuator modules,and baseband control modules.The host computer is mainly designed to realize better human-computer interaction.The Visual Basic language is used to design the receiver's control interface.The host computer can control the radio frequency hardware in real time.The digital part mainly performs spectrum analysis on the signal and obtains the frequency information of the reconnaissance signal.The test result is: The signal in the 30MHz~3600MHz frequency band can be realized and the noise coefficient is about 2~3.5dB.When the IF output is 100 kHz,IQ amplitude imbalance is 48.5mV,phase unbalance is 2.88°;When the IF output is 1MHz,IQ amplitude imbalance is 10 mV,phase unbalance is 1.44°;When the IF output is 5MHz,IQ amplitude The degree of unbalance is 20 mV,and the degree of phase imbalance is 1.8°.The IF output bandwidth is adjustable from 1 to 30 MHz and steps to 1 MHz.At the same time,frequency analysis is performed on the signal through the FPGA,and the frequency resolution is 39 kHz.