Research On C-band Pulse Modulated Signal Source

With the development of the barrel gun technology and practical use requirements,the intelligent requirements for barrel gun ammunition are getting higher and higher.How to accurately obtain the muzzle velocity of the projectile and how to efficiently transmit the signal about the bombing information to the projectile fuze control module has become a hot issue in the research of intelligent ammunition in various countries.This paper investigates how to carry out high-speed transmission of the burst instructions in the barrel gun to the projectile and real-time acquisition of interior ballistic speed information.According to the specific barrel gun type and the electromagnetic field’s structure of transmission mode in the metal circular waveguide,the paper presents a high speed command transmission and projectile ballistic velocity information acquisition scheme based on the circular waveguide TE₀₁ mode.The main work of this paper is as follows:1.Proposed a method about high-speed command transmission and projectile interior ballistic information acquisition.Fisrtly,according to the size of the specific gun type,calculated the corresponding circular waveguide TE₀₁ mode cutoff frequency,worked out the appropriate pulse modulation signal carrier frequency;Secondly,considered the TE₀₁ mode field structure characteristics,using the coaxial TEM model through the rectangular waveguide coupled and stimulated the TE₀₁ model in the metal circular tube.Finally,according to the working frequency range and high speed modulation requirements,designed the pulse modulation signal source system of PLL frequency synthesis and modulation switch based on pulse modulation signal as a transmission frame,echo signal mixed with the signal source carrier through the ring and carryed out the IF conditioning system.2.Developed a pulse modulation module for instruction modulation.Firstly,the low-phase noise frequency source module is designed by the phase-locked frequency synthesis method.The phase noise is-92.33 dBc / Hz @ 1kHz and-103.5dBc @ 10 kHz at the frequency of 4.15 GHz.Secondly,the instruction signal level is TTL level and High modulation rate requirements,the use of switch modulation mode pulse modulation function module design and production.Its modulation rate high to 16 MHz,the modulation isolation is 27 dB.3.Developed a miniaturized bomb command signal demodulation module.According to the principle of microwave detection,used the HSMS-286 K Schottky diode to design C-band high-speed detection circuit,which has achieved the 16 MHz modulation rate pulse modulation signal demodulation.4.Developed the module for exciting circular waveguide TE₀₁ mode,which include the excitation waveguide and one to four narrow band power splitter.5.Built an experimental system to simulate the experiment.The experimental results showed that the pulse modulated source and the miniaturized high-speed detection circuit can realize the high-speed modulation and demodulation of the instruction.The signal conditioning of the Doppler echo signal channel is tested by using the simulated ballistic signal.