Research And Implementation Of Phased Array Fuze Detection Technology

The current world situation is changing rapidly.Local conflicts and wars are always taking place.Unlike the “Human Wave Tactics” used in conventional wars,precision strikes have become the main form of modern warfare.Fuzes,as the key to maximize the effectiveness of weapon damage through precise guidance,are attracting more and more attention from countries.Most of the conventional fuzes use omnidirectional antenna,with low antenna gain,thus the detection range is generally close.Fuzes with phased array antenna have higher antenna gain and improved transmission power,which can meet the demand of long-distance detection mission.But the generated beam of phased array antenna is narrow.In order to have the instantaneous omnidirectional detection capability,a corresponding detection technique is needed to control the beam for spatial scanning.Based on phased array fuze,research on detection technology is carried out in this thesis.The main work contents and innovations are as follows:1)Based on the narrow beam characteristics of phased array fuze,a kind of search and tracking strategy based on beam scanning is proposed.Through the analysis of the fuze workflow,combined with the characteristic of fast beam scanning for phased array antenna,a beam scanning method for search and tracking mode is designed and basis of target judgement in two working modes is illustrated.Compared with the conventional fuze detection method,the technology can achieve capability of perigee detection with measurement of the distance between target and the beam position where the target exists.Therefore,the target detection mission can be completed by using only one single channel,which can simplify the structure of the fuze's signal channel and save hardware resources.2)In order to verify the fuze detection technology,an echo simulation method suitable for phased array fuze is proposed.The influence of the relative distance and illumination area change on the echo intensity during fuze operation is analyzed.Based on the established antenna model,an antenna pattern modulation function for the method is designed.Characteristics of the ground clutter are analyzed and its amplitude and power spectrum distribution model are established.The simulated echo signals are generated with the clutter sequences and Doppler shift.The echo simulation method is based on the moving fuze flatform and antenna scanning process,which is closer to the actual working scene of the fuze.3)In order to make the fuze have long-distance detection capability,the chirp signal is used as the transmission signal of the fuze detector to design the signal processing system.The blind zone is reduced as much as possible and the signal-to-noise ratio is improved by pulse compression and pulse accumulation to enlarge fuze's effective detection range.The envelope walking phenomenon caused by the Doppler effect caused by high-speed motion between missile and target is analyzed.The motion compensation for Doppler effect is realized by the velocity estimation.After the constant false alarm detection,the relative distance from the target is obtained.4)Based on the FPGA hardware platform,adopting the modular design idea and according to the theory of signal processing algorithm,the modules are designed and programmed.Processing methods such as parallel,pipeline architecture and time-sharing multiplexing are used to increase the calculation speed while reducing the consumption of hardware resources.The feasibility of the detection technology scheme is verified by hardware simulation.