Showing papers on "Rise time published in 2010"

Broadband Ground-Motion Simulation Using a Hybrid Approach

Abstract: This paper describes refinements to the hybrid broadband ground-motion simulation methodology of Graves and Pitarka (2004), which combines a deterministic approach at low frequencies ( f 1 Hz). In our approach, fault rupture is represented kinematically and incorporates spatial heterogeneity in slip, rupture speed, and rise time. The prescribed slip distribution is constrained to follow an inverse wavenumber-squared fall-off and the average rupture speed is set at 80% of the local shear-wave velocity, which is then adjusted such that the rupture propagates faster in regions of high slip and slower in regions of low slip. We use a Kostrov-like slip-rate function having a rise time proportional to the square root of slip, with the average rise time across the entire fault constrained empirically. Recent observations from large surface rupturing earthquakes indicate a reduction of rupture propagation speed and lengthening of rise time in the near surface, which we model by applying a 70% reduction of the rupture speed and increasing the rise time by a factor of 2 in a zone extending from the surface to a depth of 5 km. We demonstrate the fidelity of the technique by modeling the strong-motion recordings from the Imperial Valley, Loma Prieta, Landers, and Northridge earthquakes.

Submillisecond Gray-Level Response Time of a Polymer-Stabilized Blue-Phase Liquid Crystal

Abstract: The gray-to-gray response time of a polymer-stabilized blue-phase liquid crystal is investigated. As the voltage increases, rise time decreases gradually but decay time remains unchanged. A set of analytical equations is used to fit the measured results, and an acceptable agreement is obtained.

70% Efficient Relativistic Magnetron With Axial Extraction of Radiation Through a Horn Antenna

Abstract: At the Nagaoka University of Technology (Japan), Daimon and Jiang used particle-in-cell (PIC) code simulations to demonstrate that the electronic efficiency of the A6 magnetron with axial extraction can be increased from 3% up to 37% applying different diffraction outputs, from tapered cavities in a conical horn antenna to modified expanded ones that improve magnetron matching with the antenna. This paper presents PIC code simulation results for the modified magnetron design using a transparent cathode, in contrast with Daimon and Jiang's simulations that used a solid explosive emission cathode. Furthermore, by further optimizing the magnetron parameters, we demonstrate an efficiency approaching 70% with gigawatt radiation power for an applied voltage of 400 kV. By maintaining a synchronous interaction of electrons with the operating wave, we found that the radiation power increases as the square of the diode voltage up to a diode voltage of 800 kV with short rise time that does not exceed 20 ns. In addition, we show that using a transparent cathode promotes avoiding the regime of hard excitation of magnetrons.

Influence of the voltage‐time derivative in X‐ray emission from laboratory sparks

Abstract: X-ray produced by laboratory sparks in air at atmospheric pressure for rod-rod and rod-plane configurations were observed. A total of 585 sparks were applied with both polarities. The paper shows the effects of the voltage rise time and the peak voltage in the generation of x-rays. It is found here that shorter rise times and high peak voltages tend to produce more x-rays emissions with higher energies than longer front waveforms or lower peak voltages. In a similar way, higher voltage variations produce more energetic emissions. This finding suggests that the variation of the electric field before the breakdown can play a fundamental role in the x-ray production. The results are similar with the observations of x-rays produced in natural lightning where detections have been associated to leader steps before the return stroke.

Influence of rise time on partial discharge extinction voltage at semi-square voltage waveforms

Abstract: This work presents measurements of the partial discharge (PD) extinction voltage in three different types of test objects, using semi-square voltages with 2 ?s and 100 ?s rise time. A needle creating corona discharges, a twisted pair specimen commonly used for testing motor insulation and a paper/oil test object modelling the turn-to-turn insulation of a transformer winding were investigated, presenting extinction voltages between approximately 1 kV and 8 kV. For the twisted pair specimen the PD extinction voltage was significantly lower at the shorter rise time, whereas for the other test objects, just a small or no difference could be detected. The conclusion is that depending on what range of rise times and what insulation system that are studied, there may be an influence of the rise time of the applied voltage on the PD extinction voltage.

High-Power Pulse Generator With Flexible Output Pattern

Abstract: This paper presents a high-voltage bipolar rectangular pulse generator using a solid-state boosting front-end and an H-bridge output stage. The topology generates rectangular pulses with fast enough rise time and allows easy step-up input voltage. In addition, the circuit is able to adjust positive or negative pulsewidth, dead time between two pulses, and operating frequency. The topology can also be controlled to produce unipolar pulses and other pulse patterns without changing its configuration. With an appropriate dc source, the output voltage can also be adjusted to requirements of different applications. The intended application for such a circuit is algal cell membrane rupture for oil extraction, although additional applications, include biotechnology and plasma sciences, medicine, and food industry. A 1 kV/200 A bipolar solid-state pulse generator was fabricated to validate the theoretical analysis presented in this paper. In addition, to validate the analysis with simulations and prototype tests, biological test were conducted in order to examine the technical value of the proposed circuit. These evaluations seem to suggest that oil production rate from bipolar pulses may double that of an equivalent process with unipolar pulses.

High-voltage pulsed generator for dynamic fragmentation of rocks

Abstract: A portable high-voltage (HV) pulsed generator has been designed for rock fragmentation experiments. The generator can be used also for other technological applications. The installation consists of low voltage block, HV block, coaxial transmission line, fragmentation chamber, and control system block. Low voltage block of the generator, consisting of a primary capacitor bank (300 μF) and a thyristor switch, stores pulse energy and transfers it to the HV block. The primary capacitor bank stores energy of 600 J at the maximum charging voltage of 2 kV. HV block includes HV pulsed step up transformer, HV capacitive storage, and two electrode gas switch. The following technical parameters of the generator were achieved: output voltage up to 300 kV, voltage rise time of ∼50 ns, current amplitude of ∼6 kA with the 40 Ω active load, and ∼20 kA in a rock fragmentation regime (with discharge in a rock-water mixture). Typical operation regime is a burst of 1000 pulses with a frequency of 10 Hz. The operation process...

Design of a Fractional Order Phase Shaper for Iso-Damped Control of a PHWR Under Step-Back Condition

Abstract: Phase shaping using fractional order (FO) phase shapers has been proposed by many contemporary researchers as a means of producing systems with iso-damped closed loop response due to a stepped variation in input. Such systems, with the closed loop damping remaining invariant to gain changes can be used to produce dead-beat step response with only rise time varying with gain. This technique is used to achieve an active step-back in a Pressurized Heavy Water Reactor (PHWR) where it is desired to change the reactor power to a pre-determined value within a short interval keeping the power undershoot as low as possible. This paper puts forward an approach as an alternative for the present day practice of a passive step-back mechanism where the control rods are allowed to drop during a step-back action by gravity, with release of electromagnetic clutches. The reactor under a step-back condition is identified as a system using practical test data and a suitable Proportional plus Integral plus Derivative (PID) controller is designed for it. Then the combined plant is augmented with a phase shaper to achieve a dead-beat response in terms of power drop. The fact that the identified static gain of the system depends on the initial power level at which a step-back is initiated, makes this application particularly suited for using a FO phase shaper. In this paper, a model of a nuclear reactor is developed for a control rod drop scenario involving rapid power reduction in a 500 MWe Canadian Deuterium Uranium (CANDU) reactor using AutoRegressive Exogenous (ARX) algorithm. The system identification and reduced order modeling are developed from practical test data. For closed loop active control of the identified reactor model, the fractional order phase shaper along with a PID controller is shown to perform better than the present Reactor Regulating System (RRS) due to its iso-damped nature.

A feasibility study of photosensor charge signal transmission to preamplifier using long cable for development of hybrid PET-MRI.

Abstract: Purpose: A new positron emission tomography(PET)detector signal processing method, the charge signal transmission approach, is proposed for the development of a hybrid PET-magnetic resonance imaging(MRI). A number of experiments were performed to demonstrate that the Geiger-mode avalanche photodiode (GAPD) charge output could be transmitted to a preamplifier using a long cable without degrading the PET signal performance. Methods: A PET module consisted of LYSO and a GAPD with a 4 × 4 array. The GAPD output was transmitted to the preamplifier through flexible flat cables. The effect of the cable length on the PET performance was examined using seven different lengths ranging from 10 to 300 cm outside and inside the 7 T animal MRI. Four parameters (rise time, fall time, amplitude, and area of the preamplifier output) were measured as a function of the cable length using a 10 GS/s oscilloscope and three parameters (photopeak position, energy resolution, and time resolution) were measured using a 100 MS/s DAQ unit. The effect of the cable length on the MR phantom images was investigated. In addition, the effect of the PET module configuration on its temperature stability was assessed by acquiring the energy and time spectra. Results: There were no significant changes in the PET module performance as a function of the cable length, both outside and inside MRI. The performance changes in energy information, such as the amplitude, area, photopeak position, and energy resolution, were 3 % with cable lengths ranging from 10 to 300 cm and the change in the time resolution was 6 % . There were no obvious artifacts or changes in the line profile in the MR phantom images. Moreover, no manifest changes in the photopeak position and coincidence counting rate were observed in the PET modules employing the charge signal transmission approach, whereas considerable degradation of the PET module performance was observed in the voltage signal transmission approach. Conclusions: This study demonstrated that it is feasible to design a hybrid PET-MRI using the charge signal transmission approach, which is expected to have more advantages than other approaches.

Stability of Injection of a Subnanosecond High-Current Electron Beam and Dynamic Effects Within Its Rise Time

Abstract: The stability of the injection of short electron beams and the dynamic processes that occur during their transport were experimentally studied. Beams of energy 200-300 keV, current of 1-1500 A, and duration of 0.05-3 ns with a current rise time of 30-300 ps were formed in a cold-cathode electrode gap. The distribution of the accelerating electric field was highly nonuniform. The cases of vacuum and air insulation of the electron diode were considered. The shortest beams with currents of a few amperes were generated in the mode of continuous acceleration of electrons in atmospheric air. For measuring beam currents, special collector probes were used which ensured a picosecond resolution.

Solid-State LTD Module Using Power MOSFETs

Abstract: It is proposed that linear transformer driver (LTD) concept can be applied to compact repetitive pulsed-power generation. For experimental demonstration, a table-top LTD module has been constructed by using power metal-oxide-semiconductor field-effect transistors (MOSFETs) and film capacitors. It consists of 24 basic circuits and a magnetic core, contained in a cavity case having a diameter of 32 cm and a height of 1.1 cm. All MOSFETs can be turned on and off synchronously, controlled by a single optic fiber. This LTD module has been tested with operation voltage of 900 V for single shot and 700 V for repetitive operation at 500 Hz. Near-rectangle waveforms were obtained on a resistive load of 3.2n , with pulsewidth of 200 ns, rise time of 20 ns, and fall time of 40 ns. The overall system efficiency was obtained to be 76%.

Design procedure for compact pulse transformers with rectangular pulse shape and fast rise times

Abstract: Pulse modulators based on solid state technology and for pulses in the μs-range often utilize a pulse transformer, since it could offer an inherent current balancing for parallel connected power semiconductors and the turns ratio of the pulse transformer allows to adapt the modulator design to the available switch technology. The applications like radar systems, linear accelerators or klystron/magnetron modulators usually require a nearly rectangular pulse shape with a fast rise time and a as small as possible overshoot. In reality however, parasitic elements of the pulse transformer as leakage inductance and capacitances limit the achievable rise time and define the resulting overshoot. Therefore, in modulators based on pulse transformers, the design of the pulse transformer is crucial. In this paper, a step by step design procedure of a pulse transformer for rectangular pulse shape with fast rise time is presented. Different transformer topologies are compared with respect of the parasitic elements, which are then calculated analytically depending on the mechanical dimensions of the transformer. Additionally, the influence of the limited switching speed of semiconductors and the nonlinear impedance characteristic of a klystron is analyzed.

BiCMOS embedded RF-MEMS switch for above 90 GHz applications using backside integration technique

Abstract: We demonstrate a novel back-side processed, back to front self-aligned BiCMOS embedded RF-MEMS switch for the 90 to 140GHz frequency band. The switch integration is very simple, adding only one mask step to the underlying high-performance BiCMOS process. Moreover, it offers low cost, wafer level packaging. The insertion loss of the switch is less than 0.5dB up to 140GHz, and isolation is better than 15dB in the frequency range of 90 to 140GHz. The switch-on time is measured as 10µs. No performance degradation was observed after 5 billion cold switching cycles demonstrating the high reliability of the switch. An on-chip charge-pump (CP) circuit is realized using enhanced PMOS transistor to excite the switch with an output voltage of up to 50V and a rise time of 2µs.

Operating parameters of CVD diamond detectors for radiation dosimetry

Abstract: A prototype clinical radiation detector based on commercially available single crystal diamond film made via chemical vapor deposition was investigated to determine optimal operating parameters for clinical dosimetry. This study examined how changes in applied electric field affected dosimetric performance, and determined a preferred operating voltage within the limits of clinical dosimetry equipment. Dosimetric analysis included leakage current, response dynamics such as rise and fall times, sensitivity, polarity and dependence on dose and dose rate. The results of this study indicate a preference for using a setting of 62.5 V due to its minimal rise time of 2 s, including a faster time to equilibrium, yet sufficient sensitivity of 37 nC Gy−1, which was nearly independent of polarity. At this voltage, a wider range of dose may therefore be recorded with charge collecting instruments than at higher voltages. Additionally, no clear trend was found over the range of voltages tested when evaluating dose dependence (R2=1 for 0.78–7.8 Gy) and dose rate dependence using Fowler fitting parameter Δ (0.95≤Δ≤1.01). Leakage currents were negligible (

A compact high-voltage pulse generator based on pulse transformer with closed magnetic core

Abstract: A compact high-voltage nanosecond pulse generator, based on a pulse transformer with a closed magnetic core, is presented in this paper. The pulse generator consists of a miniaturized pulse transformer, a curled parallel strip pulse forming line (PFL), a spark gap, and a matched load. The innovative design is characterized by the compact structure of the transformer and the curled strip PFL. A new structure of transformer windings was designed to keep good insulation and decrease distributed capacitance between turns of windings. A three-copper-strip structure was adopted to avoid asymmetric coupling of the curled strip PFL. When the 31 microF primary capacitor is charged to 2 kV, the pulse transformer can charge the PFL to 165 kV, and the 3.5 ohm matched load can deliver a high-voltage pulse with a duration of 9 ns, amplitude of 84 kV, and rise time of 5.1 ns. When the load is changed to 50 ohms, the output peak voltage of the generator can be 165 kV, the full width at half maximum is 68 ns, and the rise time is 6.5 ns.

Design of output dv/dt filter for motor drives

Abstract: Modern PWM inverter output voltage has high dv/dt, which causes problems such as voltage doubling that can lead to insulation failure, ground currents that results in electromagnetic interference concerns. The IGBT switching device used in such inverter are becoming faster, exacerbating these problems. This paper proposes a new procedure for designing the LC clamp filter. The filter increases the rise time of the output voltage of inverter, resulting in smaller dv/dt. In addition suitable selection of resonance frequency gives LCL filter configuration with improved attenuation. By adding this filter at output terminal of inverter which uses long cable, voltage doubling effect is reduced at the motor terminal. The design procedure is carried out in terms of the power converter based per unit scheme. This generalizes the design procedure to a wide range of power level and to study optimum designs. The effectiveness of the design is verified by computer simulation and experimental measurements.

Estimation of the Mathematical Parameters of Double-Exponential Pulses Using the Nelder–Mead Algorithm

Abstract: Transient pulses for electromagnetic compatibility problems, such as the high-altitude electromagnetic pulse and ultrawideband pulses, are often described by a double-exponential pulse. Such a pulse shape is specified physically by the three characteristic parameters rise time tr, pulsewidth tfwhm (full-width at half-maximum), and maximum amplitude Emax. The mathematical description is a double-exponential function with the parameters α, β, and E0. In practice, it is often necessary to transform the two groups of parameters into each other. This paper shows a novel relationship between the physical parameters tr and tfwhm on the one hand and the mathematical parameters α and β on the other. It is shown that the least-squares method in combination with the Nelder-Mead simplex algorithm is appropriate to determine an approximate closed-form formula between these parameters. Therefore, the extensive analysis of double-exponential pulses is possible in a considerably shorter computation time. The overall approximation error is less than 3.8%.

Bipolar solid state marx generator

Abstract: A high-voltage bipolar rectangular pulse generator using a high efficiency solid-state boosting front-end and an H-bridge output stage is described. The topology of the circuit generates rectangular pulses with fast rise time and allows easy step-up input voltage. In addition, the circuit is able to adjust positive or negative pulse width, dead-time between two pulses, and operating frequency. The intended application for such circuit is algae cell membrane rupture for oil extraction, although additional applications include biotechnology and plasma sciences medicine, and food industry.

An 850-nm Normal-Incidence Germanium Metal–Semiconductor–Metal Photodetector With 13-GHz Bandwidth and 8- $\mu$ A Dark Current

Abstract: This letter presents a new germanium metal-semiconductor-metal photodetector (PD), in which an amorphous silicon (a-Si) layer is added on top of the undoped germanium substrate. The a-Si under the Ti-Au contacts serves as a barrier enhancement layer and mitigates Schottky barrier height lowering due to fermi-level pinning, hence reducing dark current. In the active region, the a-Si layer passivates surface states, thus preventing low-frequency gain due to charge accumulation and image force lowering, and improving the device bandwidth. A prototype PD with an area of 47 × 47 μm2 with 2-μm contact spacing and 1.25-μm contact width achieved a small-signal 3-dB bandwidth over 10 GHz. In an ultrafast electrooptic sampling measurement, its impulse response exhibited 15-ps pulsewidth and 30-ps rise time, which corresponds to 13-GHz bandwidth. The measured PD capacitance was 40 fF. The responsivity and dark current were 0.23 A/W and 8 μA, respectively, at 850-nm wavelength and 7-V bias.

Novel insulated gate bipolar translator (IGBT) drive and protection circuit

Abstract: The invention discloses an insulated gate bipolar translator (IGBT) drive and protection circuit. The circuit mainly comprises a power supply for providing working voltage, a voltage reference unit, an insulated-gate bipolar transistor (IGBT), a control pulse input circuit, an optical coupler P1, a primary amplifying circuit, a Vce monitoring and protecting circuit and a fault soft switch-off circuit and is characterized by also comprising an under-voltage protection unit for blocking the output of the drive and protection circuit when a power supply voltage falls to a set value and a rise and fall adjustable circuit for adjusting the switch-on rise time Tr and switch-off fall time Tf of the IGBT. The circuit has the advantages of perfect function, reliable performance and easy popularization and application.

Fast response surface temperature sensor for hypersonic vehicles1

Abstract: This paper describes the design, fabrication, and evaluation technique of fast response Surface Temperature Sensor (STS). This STS was made of chromel-constantan elements with 2.2 and 0.8 mm in diameter. The calibration technique using shock tube facility for measuring the transient surface temperature and heat transfer rate is also presented. It has been proved that the STS response time is very short (less than 50 µs), and a rise time in studies of a transient surface temperature is less than 0.5 µs.

High-Voltage and High-PRF FID Pulse Generators

Abstract: Several types of pulse generators with amplitude from 200 to 10 kV, rise time from 200 to 50 ps, pulse duration from several nanoseconds to 100 ps have been developed At amplitude of 100–200 kV maximum pulse repetition frequency (PRF) in continuous operation can reach 2–5 kHz Testing of such pulse generators has been performed, and the tests have shown that total efficiency can reach more than 60% at pulse duration of 1–2 ns Tests have also revealed that electric strength of connectors and transmitting cables rapidly decrease at pulse repetition frequency of 1 kHz and higher At an amplitude of 10 kV, a rise time of about 100 ps, a pulse duration of 05 ns, and an operating frequency of 200 kHz in continuous mode have been reached The jitter of the delay time between an external triggering pulse and the output high-voltage pulse from the generator is about 10–20 ps A new type of pulser, which forms voltage pulses with amplitude of 5–10 kV, rise time of 05–1 ns, pulse duration of 1–2 ns, operating at pulse repetition rate of 3–6 MHz, has been developed

High-Power Ultrafast Current Switching by a Silicon Sharpener Operating at an Electric Field Close to the Threshold of the Zener Breakdown

Abstract: A new principle of high-power ultrafast current switching by Si sharpener based on a successive breakdown of the series-connected structures has been experimentally implemented and theoretically studied. A voltage pulse with an amplitude of 180 kV and a rise time of 400 ps was applied to a semiconductor device containing 44 series-connected diode structures located in a 50- transmission line. Due to a sharp nonuniformity of the applied voltage distribution across the length of the device, the structures operate in the successive breakdown mode. Each successive structure breaks down with a shorter time interval as the electromagnetic shockwave builds. In the experiments in a 50- transmission line, we have obtained 150-kV output pulses having a 100-ps rise time. The maximum current and voltage rise rates amount to 30 kA/ns and 1.5 MV/ns, respectively. In the numerical simulations, the ionization rate of the process-induced deep-level centers, as well as the band-to-band tunneling, is taken into account. The calculations show that, at a reverse voltage rise rate across the structure of over 10^13 nV/s, the electric fields that are close to the threshold of the Zener breakdown can be achieved even if the structure contains deep-level centers with a concentration of 1011 to 1012 cm-3.

An explicit model for delay and rise time for distributed RC on-chip VLSI interconnect

Abstract: In this paper, simple explicit delay and rise time expressions for uniformly distributed RC on-chip interconnect line are derived based on Elmore's approximations. Here, an n-cell RC ladder network with capacitive load is used. Transfer function for the n-cell RC ladder network is obtained by using the transmission line parameter matrix for each cell. In order to deduce the transfer function, the transmission line is modeled by a lumped parameter network. From this transfer function, explicit delay and rise time expressions are derived by using Elmore's definitions. The calculated delay and rise times by our proposed closed form expressions are compared with the results obtained by SPICE simulation for n=2, 3, 4, 5, 6, 7 cell ladder networks with capacitive load.

An implementation of step recovery diode-based UWB pulse generator

Abstract: Ultra-wideband (UWB) wireless communications and carrierless UWB radar technology use narrow nanosecond or sub-nanosecond pulse as the transmission medium. This paper presents an implementation of sub-nanosecond level pulse generator. The main principle is using the rapid step recovery characteristics of step recovery diode (SRD) to shape the driving pulse, shorten the rise time, narrow the pulse width, then gain the required UWB pulse. The final actual measured pulse width is about 600 ps, amplitude is about 5 V. It is enough for practical applications, but the ringing is a little too big, the amplitude is relatively low. The paper provides a simple method to design UWB pulse generator. Although there is some room for improvement, it has important reference value for the use of SRD in UWB pulse generating in the future.

The GIMLI: A Compact High-Power UWB Radiation Source

Abstract: This chapter presents the design and performances of a compact, general-purpose, high-power ultra-wideband (UWB) source named GIMLI. The system was designed for dual use, homeland security and military applications. It is powered by a compact, coaxial 12-stage Marx generator with a rise time lower than 25 ns and an operating voltage up to 360 kV. A fast monocycle pulse is sharpened using a pulse former (MPF). The shaper stage comprises a switching module including a peaking and a grounding multi-channel spark gap under a N2 pressure of 6 MPa. The module is followed by a monopulse-to-monocycle converter based on a coaxial Blumlein pulse forming line. The bipolar signal measured at the output of the MPF has a duration shorter than 2 ns with a rise time of 250 ps. The peak-to-peak output voltage is 250 kV on a 50 Ω resistive load. Repetitive operation of the MPF has been experienced with a 200 Hz Tesla transformer developed by the CEA (Commissariat a l’Energie Atomique). Electromagnetic energy is focused by a dedicated antenna. The designed antenna is a TEM half-horn with two ridges which improve the low-frequency focusing. High-power radiation tests show that the field measured at a distance of 9 m from the TEM Horn-antenna is higher than 120 kV/m.

Programming methods for phase-change memory

Abstract: Set pulses with finite rise time that heat up phase change alloy between about nucleation temperature and about average of crystallization and melting temperatures are proposed for programming phase change memory from reset to set state in order to minimize energy during this transition and to achieve uniform set state distribution. Non-square reset pulses with finite rise time that heat up phase change alloy at or above melting temperature are proposed for programming phase change memory from set to reset state in order to improve cell endurance.

4kV/30kHz short pulse generator based on time-domain power combining

Abstract: Using avalanche transistor as the switch of Marx circuit, a new type of all-solid-state pulse generator is researched, which can generate short unipolar pulse. The peak-voltage is 2kV as the load resistor is 50Ω, the pulse width is 1.6ns, the rise time is 250ps, the jitter is less than 30ps, and the repetition can reach to 30kHz. Then, combining short pulse through mcirostrip power combiner is analyzed. Four high-stability pulse generators are combined, which generates higher peak-voltage to 3.9kV. The combining efficiency reaches to 97.5%.

The Effect of Approach Speed and Charge Voltage on an Air Discharge

Abstract: In this paper, a new electrostatic discharge (ESD) testing system is designed and the influence of the approach speed and charge voltage on ESD parameters, e.g., discharge current, rise time, and induced voltage in a semicircular loop antenna, and also the reproducibility of experimental results are analyzed. It is concluded that, as the charge voltage is constant, ESD parameters are linearly proportional to the approach speed, the reproducibility increases with growth of the approach speed, especially at 0.8 m/s. As the approach speed is constant, the field strength generated at low charge voltage is stronger than that at high charge voltage; better reproducibility can be also reached at low charge voltage. These important conclusions provide the foundation for developing standard method for air ESD immunity tests.