| In recent years,multiple-input multiple-output(MIMO)radar is a hot research topic.Based on MIMO radar,the concept of MIMO fuze is presented by introducing MIMO technology into the radio fuze.Through array antenna technology,MIMO fuze can achieve the target angle estimation.The antenna elements emit orthogonal signals,which can not be superimposed in the space,and form a low-gain wide beam to achieve a full range of target detection.MIMO fuze has good abilities of anti-interception and anti-interference.By using the characteristics of waveform diversity,it has advantages in the target detection and parameter estimation.In this paper,the principle of MIMO fuze is researched.The PSK signal and its signal models in the fuze are analyzed.This paper designs the MIMO fuze system of four antennas and completes the design of its whole circuits.A national defense invention patent has been applied.The RF circuits in the MIMO fuze system are designed.Two papers are published.The main research works include:(1)The effect of microstrip discontinuity on the transmission characteristics is studied.The arc and 45°out miter bend are analyzed,and the optimal chamfering rate is obtained by optimizing the design.(2)A 2.4GHz modulation circuit of the MIMO fuze is designed with the quadrature modulation chip AD8346,amplifier AD8132 and so on.(3)A low-pass filter is designed.With the same order,the Chebyshev filter is better by comparison and analysis.The impedance matching circuit is designed to realize the matching between the filter and the front circuit.(4)To ensure that the signal after demodulation will not lose its phase information,adapting the method of orthogonal demodulation,a 2.4GHz demodulating circuit is designed whith the quadrature demodulation AD8347.A VCO that the system requires is designed with the chip MAX2750.(5)With the laser direct write technology,the PCB board is completed by stripping excess conductive layer and leaving a circuit pattern.Test the circuits to achieve the function designed.After joint debugging,they will form a complete modulation and demodulation circuit of the MIMO fuze. |
