Wei Guanghui

EMP energy transfer function on EED

The hazards of electromagnetic radiation to ordnance (HERO) program has extensively tested the detonating device, called electro-explosive device (EED), which heats up and initiates detonation via current flow. EED accidents can occur due to the action of an electromagnetic pulse (EMP). Any kind of system can be considered as an antenna to receive EMP energy and this energy may couple to the EED. The EED and its related problems are introduced and heat flow equations are studied. The amount and type of current induced in wires to an EED depends on the type of receiving antenna. Three basic types of antenna are discussed, loop antenna, dipole antenna and top-loaded antenna.

Effect of two emission antennas on field uniformity in a reverberation chamber

The simulation models of reverberation chamber excited by two antennas and single antenna are constructed. The field uniformity at 80MHz and 120MHz are obtained when single antenna and two antennas are utilized respectively. Compared with single emission antenna, the field uniformity is improved using two emission antennas. The mechanism of field uniformity improved is analyzed. Besides, using two antennas could lower the requirement of power amplifier than one when same field strength is desired. So reverberation chamber using two antennas could decline the cost of electromagnetic compatibility test.

FDTD evaluation of transmission characteristic in GTEM cells

The finite difference time domain (FDTD) technique is used to analyze the transmission characteristic in GTEM cells in a polar coordinate system. To simulate the propagation of the wave at the terminal section a first order absorption boundary condition was implemented. The scattering coefficient and characteristic impedance are calculated. The analysis has been carried out in the frequency domain response with pulse source by means of a discrete Fourier transform.

Research on electromagnetic environment effects for typical shortwave communication equipment

The UWB and CW irradiation effects on typical communication equipment were researched in this paper. The UWB experiments indicate that when the irradiation E-field intensity is larger than 50kV/m, the display panel fault of shortwave communication station appears. The coupling channel is the display panel of the station. When the irradiation E-field intensity is larger than 150kV/m, the effect of display panel fault, break down, restart and voice stoppage appears. The main coupling channel is the power supply cord of communication station. The continuous wave experiments indicate that when the interference frequency is close to the station working frequency, it has the best interference effect. When the frequency variation Δf is smaller than 15kHz, the interference effect could be preferable, and the communication station interference is sensitive to E-field intensity. The research conclusions above provide technology reference to further study electromagnetic environment effects for shortwave communication equipment.

Effects of propagation on the return stroke radiation fields

In this paper, we discuss the effects of the height of channel, the return stroke speed and the permittivity of ground on the return stroke radiation fields based on TL, MTLE, TCS and BG model. We assume a common current wave shape at the channel base and then calculate the electromagnetic field under different conditions. Some useful conclusions have been made in the paper.

Study on ESD characteristics and its effect mechanism

Based on experimental study on microcircuit and electric explosive device (EED) applied by electrostatic discharge (ESD), the characteristics and its electric conduction law of ESD are introduced. And it is shown that the generally accepted Ohms law is not followed at times under very high electrostatic field. In another words, ESD discharge curve is not an exponential decay one. ESD may form a hazard to microcircuit and EED. And its effect mechanism includes thermal effect of adiabatic process, electromagnetic interference from broadband electromagnetic radiation, overstress in high potential electrostatic field and field-caused breakdown effect etc. The failure rate may reach about 50% for unprotected MOS circuits and 10% for bipolar circuits due to general ESD hazards. The electrostatic ignition energy of EED is smaller with 2-3th power than that of the EED which is ignited through electrifying.

Development and application of LEMP-simulating device

In this paper, a device is presented which is used to simulate a remote lightning electromagnetic environment. The device is composed of a set of surge generators and a set of parallel plate transverse electromagnetic wave cells (PPTCs). The field in the PPTCs is uniform so as to test the immunity of EUT. Experiments have been performed to testify its efficiency and feasibility. The results show that the device can work well.

Test Research on UWB Effects and Mechanism of Radio Fuze

This research indicates that the fuzes EED itself and the nonworking status fuze are safe in the radiation of UWB. Because of the SCR (silicon controlled rectifier) in fuze mistakenly turning from off status to on status, the fuzes under test all explode when the peak-peak E-field of the UWB is 106 kV/m

Research on Electrostatic Discharge Radiation Field Simulating Technology

Publisher Summary This chapter presents a study of an electrostatic discharge (ESD) radiating field simulator, which is composed of pulse voltage generator, transmission cell, and matched load resistance, on the basis of analyzing characteristics of ESD electromagnetic pulse (EMP). The influences to the output waveform are discussed, such as pulse voltage generators capacity, discharge switch, circuit loop inductance, and charging voltage. Because of ESD pulse with a rise time 0.7-1ns, it is faster than high-altitude electromagnetic pulse (HEMP). So, simulating is more difficult. To simulate ESD radiation field, the chapter adopts Pspice simulating and numeric value calculating to analyze the important parameter of high-voltage pulse power influence to ESD waveform. With the development of science and technology, density of integrated circuit of semiconductor is increasingly improved, but power consumption is lower and lower. Working frequency of circuit is advanced. The loss resulted from EMP is growing year by year. To reduce these damages, a mechanism of action of EMP to microelectronic device is presented.

A NEW TEST METHOD AND DEVICE OF FRICTIONAL VOLTAGE DECAYING FOR FABRICS

Abstract On basis of experimental study and consideration about the two ways of charge dissipation — corona discharge and electrostatic conduction, a test method of frictional voltage decaying which can evaluate the electrostatic properties of fabrics is presented, and the frictional voltage decaying test device for fabrics is developed. Experimental data show that this method and device can evaluate the electrostatic properties of fabrics overall.