Research On Key Technologies Of Missile-borne Detection Based On RF Reconstruction

In view of the complex electromagnetic environment of battlefield and the serious threat of enemy active jamming to RF.A reconfigurable RF front-end is used to adaptively select the working frequency band by perceiving the electromagnetic information of the working environment,thus to greatly improving its anti-interference ability.The main work is summarized as follows:(1)Through the analysis of several reconfigurable RF front-end implementation methods,this paper adopts multi-channel integration method to complete the design of missile-borne detector based on RF reconfiguration technology,and expounds the specific functions of each part.This paper focuses on RF single-pole-double-throw switch,electro-tuning filter and FPGA-based down-conversion technology.(2)One of the key components for implementing RF reconfiguration in a multi-channel form is the RF switch.In this paper,RF MEMS is used to realize the SPDT switch in combination with the requirements of the small space and the working frequency band(X and Ka band).A series-parallel RF MEMS single-pole-double-throw switch is designed.After simulation,the isolation of the cut-off switch in the system operating frequency range is lower than-25dB,the insertion loss of the on-state switch is better than-0.1dB,the return loss is better than-20dB,which thus verify the correctness of this design.(3)In order to save space resources,this paper uses the same IF processing circuit after mixing the RF signal.Electrically tuned filter is the key component of the the two choices of IF signal frequency.This paper uses microstrip line to load the varactor diode to realize the electric tuning filter,and finish the simulation design work according to the first IF frequency setting.The result shows that the tunable range can meet the requirements,and the insertion loss is better than-3dB.(4)In order to reduce the signal processing chip pressure,this paper applies to the digital down conversion technology between ADC and signal processing chip.NCO(numerical control oscillator),CIC filter,HB filter and FIR filter based on distributed cordic algorithm are simulated in FPGA simulation software.Matlab simulation results verify the correctness of the module design.