Fm Doppler Fuze Signal Processing Technology

The bombing point of Frequency Modulation (FM) Doppler fuze is independent of the reflection characteristics of targets in electromagnetic waves. This fuze has perfect properties of distance selection and anti-interference, so it has been widely used in the application of the projectile fuzes.The FM Doppler fuze measures the distance between artillery shell and target by beat signals, and identifies the target by Doppler signals. On the basis of the analysis to the signals of the triangular modulated linear frequency-modulated Doppler fuze system, the principle of parameters selection is discussed in this thesis, and then the process of the beat signals during projectile target crossing and the capability of the circuit in aspect of suppressing jamming are presented with Matlab. In addition, a digital circuit for frequency measurement based on the software of Xilinx and the hardware of XC95144XL CPLD is designed, and then a series of frequency measurement logic simulations are carried out under different working conditions by means of ModelSim. Finally, the design and implementation of different circuits used for signal generation, beat signal processing, Doppler signal processing and large-signal blockage are proposed, and then all the circuits are tested in the RF signal processing platform of NI. At the same time, some experiences in the process of designing and implementing hardware which is based on CPLD are summarized at the last part of this thesis.