Development Of Measurement Equipment Of Nanosecond Pulse Based On Virtual Instrument

At the beginning of 60's in 20 centuries, due to the development of physics, the research of nanosecond pulse became an important problem to resolve. Seen from time domain, the rising edge of nanosecond pulse is very steep. Meanwhile the band-width of nanosecond pulse is very wide in frequency domain. So, the measurement system of nanosecond pulse owns some new features. First, the rising time of nanosecond pulse is just several nanoseconds, sometimes sub-nanosecond. So, it is very harsh for the measurement system. Secondly, we must insure that the measured signal can stand for the real signal we want. But due to the insufficient bandwidth of general measurement system, the signal we get is always distorted. So we must think out a method to regulate the signal we get in order to acquire the real signal. Finally we must prevent the noise from outside, so the shield must be designed to measurement system. It is very necessary to study further based on these.For this, a lot of researchers have been thinking some ways to resolve the problem. Some researchers just pay attention to the improvement of the hardware in order to get real signal, but some limits exist. So, the software is used to make up the shortage of hardware. Here, a resistance voltage divider is designed to measure high voltage nanosecond pulse. Due to the capacitance to the earth and its own inductance, the signal we get is distorted. To make up the shortage of the voltage divider, the software of LabVIEW is used to solve the problem. With LabVIEW, we can recognize the measurement system and regulating the distorted signal.LabVIEW is the most representative graphical development terrace of American NI Company. It is a graphical language (G language).It is mainly applied to the field of instrument control, data acquisition, data analysis and data display etc, and it's common to many different operating system. After the hardware terrace and I/O interfaces are fixed to the computer, we can program different software to carry out different function in stead of changing the hardware to satisfy different needs. The Virtual Instrument breaks the restrictions of traditional instrument, such as: data processing, data displaying, data delivering and data saving. It is inimitable for traditional equipment. Here, LabVIEW is used to measure the nanosecond pulse, and it makes great sense in the field of system recognize and signal reconstruction.In this paper, a program is made with LabVIEW to recognize the measurement system and signal reconstruction based on the data we get. If we can get the input and output signal data of the measurement system, then input these data to the program, we will get the mathematic model. Next, we can easily reconstruction the real nanosecond pulse. Difference formula and digital filter model can be used to measurement system. But the mathematic model can not stand for the real inner structure of real measurement system. They are just the same from outside. System recognizing and signal reconstruction is the key point of this paper.Through the experiment verification, the software can recognize the system and reconstruct the signal well. It achieves the expected purpose.