The Designs And Trials Of VHF-band Lightning Signal Simulator

The main content of this research mainly focus on the design and trail of a VHFband random waveform signal source, to which assist the experiments that estimated thesources positioning accuracy of the WuHan three-dimensional lightning location network(3D-LLDN). Specific design for airborne equipment or balloons equipped withequipment to complete the specified test, combined with Wuhan3D LLDN positioningaccuracy of the estimated field test requirements for specific functional design, theanalog VHF band natural lightning radiation properties of random waveform signalsource. The VHF lightning random waveform signal source hardware design includingFPGA digital circuit design and VHF acoustic wave filter circuit design, frequencyadjustable in analog-to-digital signals mixed circuit design, analog high-power amplifierdesign. Specifically related to FPGA-based software radio technology; random waveformsignal generator theory; digital phase-locked loop technology; digital and analog filterdesign theory. In the VHF analog lightning random waveform signal source design, fromchip selection to the printed circuit board layout and other aspects have to do a carefulconsideration; the Verilog language programming FPGA chip controllable source chipunified configuration; signal source working status query, maintenance and programupgrades via RS232serial port and ISP interface; in order to facilitate future sourceextensions, reserved plenty of on-chip FPGA chip internal resources; redundant hardwaredesign with programmable software design combined with enhanced flexibility andscalability of the signal source. The subject also designed and implemented a simulationmodel based on MATLAB language, motion characteristics sounding balloons carryingthe signal source to the sky and landed process simulation, the simulation results of thetrials of important guiding significance. Before the trials, the waveform of the VHFanalog lightning random waveform signal source, radiated power, amplitude-frequencycharacteristics, noise figure and gain of the indicators were fully tested, given thedetailed test results; test results show that the source indicators meet the designrequirements. The VHF analog lightning random waveform signal source in Wuhan3D-LLDN carry out the accuracy of the estimated trials of the test, the time differenceand positioning accuracy estimated test various types play an important role, and alsofully validated the correctness of the signal source design and practical significance.