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In this paper, we show the feasibility of improving the performance of a high voltage and high repetition avalanche transistor pulse generator by applying a two-phase immersion cooling technique. The forced air cooling, single-phase immersion cooling, and two-phase immersion cooling technique was applied to a 60-stage sub-nanosecond pulse generator. The experimental results indicate that the two-phase immersion cooling technique can effectively control the temperature rising and thus reduce the time base jitter and voltage amplitude jitter. Five types of dielectric fluid with different boiling temperatures were comparatively studied. The FC-72 was finally adopted for the balanced performance on voltage amplitude and repetition rate. The two-phase immersion cooling technique could reduce the thermal resistance between the case and ambient, and increase the power from 330mW to 876mW. With this cooling method, the surface temperature of the transistor can be effectively controlled below 62. The pulse generator could achieve outstanding performance with a voltage of 2350 V and a rise time of 180 ps. It can work stably at 200 kHz for more than 30 minutes, and the burst repetition rate could be 260 kHz within one minute. This work offers new perspectives in high repetitive avalanche transistorized sub-nanosecond generators.

Objective A recently introduced Spinal Cord Stimulation (SCS) system operates at 10 kHz, faster than conventional SCS systems, resulting in significantly more power delivered to tissues. Using a SCS heat phantom and bioheat multi-physics model, we characterized tissue temperature increases by this 10 kHz system. We also evaluated its Implanted Pulse Generator (IPG) output compliance and the role of impedance in temperature increases. Materials and methods The 10 kHz SCS system output was characterized under resistive loads (1-10 KΩ). Separately, fiber optic temperature probes quantified temperature increases (ΔTs) around the SCS lead in specially developed heat phantoms. The role of stimulation Level (1-7; ideal pulse peak-to-peak of 1-7mA) was considered, specifically in the context of stimulation current Root Mean Square (RMS). Data from the heat phantom were verified with the SCS heat-transfer models. A custom high-bandwidth stimulator provided 10 kHz pulses and sinusoidal stimulation for control experiments. Results The 10 kHz SCS system delivers 10 kHz biphasic pulses (30-20-30 μs). Voltage compliance was 15.6V. Even below voltage compliance, IPG bandwidth attenuated pulse waveform, limiting applied RMS. Temperature increased supralinearly with stimulation Level in a manner predicted by applied RMS. ΔT increases with Level and impedance until stimulator compliance was reached. Therefore, IPG bandwidth and compliance dampen peak heating. Nonetheless, temperature increases predicted by bioheat multi-physic models (ΔT = 0.64°C and 1.42°C respectively at Level 4 and 7 at the cervical segment; ΔT = 0.68°C and 1.72°C respectively at Level 4 and 7 at the thoracic spinal cord)-within ranges previously reported to effect neurophysiology. Conclusions Heating of spinal tissues by this 10 kHz SCS system theoretically increases quickly with stimulation level and load impedance, while dampened by IPG pulse bandwidth and voltage compliance limitations. If validated in vivo as a mechanism of kHz SCS, bioheat models informed by IPG limitations allow prediction and optimization of temperature changes.

To satisfy ever higher kick strength requirements in reduced space, present and future fast kicker magnets in particle accelerators must often be of short-circuited delay line type, despite the full voltage reflection produced. Three EEV ceramic thyratrons, types CX 1154 (single-gap), CX 1168 (double-gap) and CX 1171 (triple gap) have been tested in inverse diode mode in a cable PFN pulse generator to absorb these reflections. The single-gap tube operated without difficulty if triggered prior to the reflection arrival. The refusal voltage was then limited to 2 kV during a few tens of nanoseconds. The double and triple-gap tubes required an extra R-C arrangement on their gaps closest to the anode to operate as inverse diodes. They then exhibited low refusal voltage (respectively 4.kV and 6 kV during some 30 ns) but only when the operating voltage was higher than 35 W. Pre-triggering had no beneficial effect. These results are discussed in terms of their acceptability for the different kicker magnet applications encountered in present-day synchrotron complexes.

The proposed compact solid-state modulator for the generation of high-power electromagnetic (HPEM) pulses uses a lithium polymer battery as the input power source and is capable of achieving a 100-Hz pulse discharge rate with a peak voltage of 400 kV for 2 min. The developed pulse generator consists of two charging units. The primary charging unit is designed to work with 200-A battery current, which increases switching losses and temperature increments at the main switch. To compensate the problems, a half-bridge three-phase structure is connected to transformers via the proposed delta-star connection that decreases the turns ratio of the three-phase transformer effectively. Furthermore, the resonant components are intentionally placed on the secondary side of the three-phase transformer, which is characterized by low current and high voltage conditions. The secondary charging unit uses the resonance between the two capacitors, and the inductor must protect not only the controller, which is susceptible to HPEM pulse effects, but also the output rectifying diodes of the primary charging unit from the peak 20-kA pulse discharging effect. The design procedures and analysis are verified with simulations for each charging unit. The experimental results using various loads, including the actual tesla transformer, validate the system performance and confirm a 94% power efficiency with a peak power density of 431 W/L.

A real-time digital time-stamp sorting algorithm used in the In-Beam positron emission tomography (In-Beam PET) is presented. The algorithm is operated in the field programmable gate array (FPGA) and a small amount of registers, MUX and memory cells are used. It is developed for sorting the data of annihilation event from front-end circuits, so as to identify the coincidence events efficiently in a large amount of data. In the In-Beam PET, each annihilation event is detected by the detector array and digitized by the analog to digital converter (ADC) in Data Acquisition Unit (DAQU), with a resolution of 14 bits and sampling rate of 50 MS/s. Test and preliminary operation have been implemented, it can perform a sorting operation under the event count rate up to 1 MHz per channel, and support four channels in total, count rate up to 4 MHz. The performance of this algorithm has been verified by pulse generator and 22Na radiation source, which can sort the events with chaotic order into chronological order completely. The application of this algorithm provides not only an efficient solution for selection of coincidence events, but also a design of electronic circuit with a small-scale structure.

This article puts forward a high repetition rate and high-voltage resonant pulse generator for plasma-assisted milling. This circuit uses only one semiconductor switch with an antiparallel diode and works in the resonant mode with the help of a resonant inductor, a resonant capacitor, and a pulse transformer to generate high-voltage pulses. An equivalent circuit of the proposed topology considering parasitic elements is established. Based on the equivalent circuit, the working principle of the pulse generator is analyzed in detail. In order to verify the theoretical analysis and circuit operation, a laboratory prototype with a 150-V dc input is implemented. The pulse repetition rate can be adjusted from 5.32 to 18.90 kHz, and the peak output voltage correspondingly varies between 8.84 and 11.7 kV. The pulse generator is used to drive a dielectric barrier discharge plasma-assisted milling chamber. Experimental results show that the pulse generator can work stably.

The rising edge of the output pulses affects the discharged mechanism and efficiency of the nonthermal plasma generation. In the traditional Marx-type pulse generators, the magnetic isolation driving circuit could not adjust the rising edge of the output pulses and limits the application on a capacitive load. In this article, the factors affecting the rising edge of output pulses are analyzed. And a driving circuit based on magnetic isolation is proposed, which can control the rising edge of the output pulses. A synchronous driving signal is used to control multiple groups of switches using different sequences, and the magnetic core does not limit the driving signals. The experiments were carried out using a seven-stage solid-state Marx modulator. From the results, the rectangular pulses and stepped pulses are obtained at a capacitive load, and the 0.1– $2.3~\mu \text{s}$ adjustment rising edge can be obtained under 0–5 kV output voltage.

This brief presents the design and implementation of an energy efficient high-voltage (HV) pulse generator for MEMS capacitive sensors and actuators. The core circuit of the proposed HV pulse generator consists of four dual-mode switched-capacitor voltage doublers (D-SCVDs). Dynamic output impedance (DOI) method is proposed and implemented to improve energy efficiency during the rising edge generation. Load energy recycling (LER) method is also used during the falling edge generation to reduce the overall energy consumption. The proposed circuit achieves an end-to-end energy efficiency of 43.5% with 250 kHz driven frequency under 550 pF capacitive load and 3.3V supply. The maximum pulsing voltage achieves 15.4V and standby power is measured as 9.8 nW. The proposed design is implemented in SMIC standard $0.18\boldsymbol{\mu }\text{m}$ CMOS process occupying a core area of $700\boldsymbol{\mu }\text{m}$ by $800\boldsymbol{\mu }\text{m}$ .

In this study, we report on system advancements for an ultrawideband (UWB) microwave radar prototype for early breast cancer detection. We introduce an integrated circuit (IC) pulse radio as a suitable replacement for both a bulky and expensive off-the-shelf pulse generator and a clock. To assess the system's suitability as a breast screening prototype, we compare measurements on two different experimental breast models (phantoms) with the established and previously reported prototype using off-the-shelf components and the here-introduced IC. We test both systems on a homogeneous fat-mimicking phantom with a 2-mm skin layer as well as a phantom with a 2-mm skin layer and glandular insertions, while the antennas, antenna housing, and sampling oscilloscope are the same for both systems. Additionally, we advance with the IC to higher frequencies, aiming to comply with the band intended for microwave imaging devices with medical applications. Furthermore, we compare the economic requirements of the IC and of the previously reported system by evaluating their cost and compactness. The objective of this study is to investigate if the IC pulse radio can replace bulky off-shelf components to allow us to implement the pulse generation circuitry in one flexible circuit board with the switching and antennas.

The application of inductive energy storage in the generation of high-current pulses has attracted considerable attention during recent years. In this article, a new inductive high-current pulse generator circuit is proposed based on XRAM (MARX spelled backword) current multiplier converter concept and multistage pulse transformers by using power electronic switches. This circuit is capable to recover the residual energy and generate repetitive high-current pulses with a flexible output pattern. To verify the circuit operation, simulation and experimental results of a two-stage laboratory prototype are presented. The results confirm the theoretical analysis and show the validity of the converter scheme.

Trigger injection and its influence on performances of a single-gap pseudospark switch were studied by using a high-dielectric trigger unit and two types of pulse generators, where pulse parameters, polarity effect, anode voltage, and electrode geometries were varied. It is found that pulses with the rising edge of nanosecond scale can cause diffused electron emission in a large region of the trigger unit, while the slower pulses result in a localized surface flashover. The trigger injection is strongly polarity-dependent, and the way of applying the negative pulse voltage to the outer electrode is more favorable. Not all injected electrons can contribute to the triggering process, and the only factors that can lead to higher charge quantity and energetic components of electrons with a short injection delay are helpful to reduce the trigger delay. A model considering the potential penetration is presented to explain the influence of trigger injection, anode voltage, and electrode geometries. When trigger injection is strong enough or the ratio of cathode hole diameter to its thickness is relatively large, the trigger delay remains constant at different anode voltage; otherwise, it decreases as the anode voltage increases.

The good performance of a clock generator circuit in the power supply for triger TTL IC is very influential on the success of the lab. A series. Therefore, the effectiveness of use must be adapted to its use in the practicum. To create a clock generator circuit as a source of pulses from a digital counter IC, a timer IC can be used. This pulse generator or clock generator can be used for clock sources in making counters up and down. Clock generators are often referred to as clock generators. The pulse generator in making the circuit is often used linear integrated circuit (IC: Integrated Circuit). A linear IC that is commonly used in general is usually the NE555 which is a timer IC. As a timer it can also be used analogically as a Clock Generator or pulse generator which can generally generate the frequency or time as needed.

This article describes a modification and an experiment conducted on a solid-state pulsed power modulator (SSPPM) for medical linear particle accelerator (LINAC) applications. Depending on the operating condition of the magnetron, an existing design of an insulated-gate bipolar transistor (IGBT)-based modulator is modified, from a positive pulse generator to a negative pulse generator. The design of the gate driver circuit of the pulse discharging IGBTs is also slightly changed to secure reliability against the arc condition. The developed modulator has the following maximum output—pulse voltage of −40 kV, pulse current of −100 A, pulsewidth of 5 μ s, and pulse repetition rate of 250 Hz. By adapting the proposed design to the pulsed power modulator for driving the magnetron, high peak and average power densities of 43 kW/L and 48.9 W/L, respectively, can be achieved. The experimental results from various tests conducted using a resistor load, including a rated operation and an arc protection, verify the robustness and utility of the developed SSPPM for medical LINAC applications. An experiment using a 9.3-GHz 1.7-MW X-band magnetron is also conducted. The developed modulator achieved a successful arc protection operation for the arc generated in the waveguide during the magnetron drive test.

With the development of high-power microwave technology, the output power of the pulse generator is required more and more higher. In this paper, it is realized by increasing the output power of the module while the output impedance of the module changes little. The module of the generator is based on pulse forming network (PFN) and linear transformer (LT). Four Blumlein PFNs with arc-type configuration and 24 Ω characteristic impedance were connected symmetrically to the primary coil of the LTD and driven by two identical laser triggered spark switches to ensure four Blumlein PFNs synchronizing operation. On this basis, a two-stage high-power pulse generator based on PFN-LT is developed. The following technical parameters of the generator were achieved on a 12 Ω high-power solid resistor: output voltage amplitude of ∼250 kV and output power of ∼5.2 GW at a repetition rate of 5 Hz.

Research on the effect of pulsed electric field in cell electroporation attracts more attention, especially tumor ablation. This puts forward higher requirements for pulsed electric field parameters. The shape of the pulse waveform was also required in different electroporation applications. Based on this, a multilevel pulse generator with series capacitor structure was proposed in this article. Besides, it can also obtain the different shapes of the pulse waveforms by controlling the timing of semiconductor switches. The voltage amplitude, the number of pulses, and the pulsewidth are all adjustable. A ten-level test prototype with 11 switches was built. The structure was simple and was more compact. It can work stably under the simulated small resistance load. Finally, when the dc charging voltage was 1 kV, the system can achieve a maximum output voltage of ±500 V. The number of pulse in one pulse sequence was 1–500. The pulsewidth was adjustable from 1 to $10~\mu \text{s}$ . By controlling the switch’s timing, it can also obtain the multilevel voltage output, exponential waveform voltage output, and composite waveform output combined narrow pulse with wide pulse.

Marx generator is a voltage boosting device for power pulse compression, in which its capacitors are charged in parallel and discharged in series. To get a higher voltage boost ratio, high-voltage silicon stacks have been applied to substitute the isolated inductances in this study. Experiments with two isolation modes in the Marx generator have been carried out. Experimental results reveal that the high-voltage silicon stacks with the parameters of 50 kV/1 kA used in the Marx generator can increase the voltage step-up ratio to 168.6:1, up from 141:1 and 162.9:1 when isolating inductances and silicon-stacks with parameters of 50 kV/3 kA are applied, respectively. Moreover, the silicon stack-isolating-type Marx generator can almost eliminate the pre-pulse existing on the load if the isolated inductances employed. Therefore, it is crucial to choose appropriate high-voltage silicon stacks as the isolating devices in the Marx generator designed in this study.

The pulse generator based on drift step recovery diode(DSRD) has broad development prospects in the research of high pulse repetition frequency(PRF), high power pulse generators. In this letter, a pulse generator based on DSRD is successfully developed. The design of circuit topology and design principles are presented. The pulse generator can work stably outputting almost 30kV peak voltage at 100 kHz PRF or 140kV at 25kHz with a 50k $\Omega $ load. What’s more, the influences of power supply voltage and load resistance are studied experimentally.

Water treatment is one of the most important issues for all walks of life around the world. Different from the conventional water treatment technology, the advanced power electronic pulse technology has unique features and advantages for the modern water treatment. Unfortunately, there is no literature reported to describe them in a comprehensive and systematic way. To fill this gap, an overview of modern power electronic pulse generators (PPGs) for water treatment is presented. This article, for the first time, classifies the different types of PPGs from the viewpoint of pulse formation. Each of them is discussed, and the advantages and disadvantages are compared and summarized. Aside from that, this article presents the development and trend of the pulse generators suitable for the specified water treatment processes such as electrolysis, sterilization, and discharge degradation. Finally, a list of more than 100 relevant technical papers is also appended for a quick reference.

In recent years, semiconductor switches have gradually replaced traditional gas switches due to their long lifetime and smaller volume. However, the rated current of the semiconductor switches limits the applications of the all-solid-state pulsed power generators. Usually, multiple semiconductor switches or pulse generators are required in parallel to share a large current in the case of the enormous power applications. In this article, a new high-current all-solid-state pulsed power generator based on Marx generators connected in parallel was proposed. One group of semiconductor switches was used to control the charging of the Marx generators. The driving circuits can be simplified due to fewer switches. It can also improve the discharge frequency and the output voltage over a capacitive load. Six 4-stage Marx generators connected in parallel have been employed to verify the proposed topologies on a capacitive and a resistive load. From the experimental results, with 1.2 kV, 150 A, and 2.4 kV, 50 A, pulses have been got on an 8- $\Omega $ resistive load and a 440-pF capacitive load, respectively. The balanced output currents can reduce the output voltage overshoot and make the system more stable and reliable.

Square wave pulses have been identified as more lethal compared to exponential decay pulses in PEF applications. This is because of the on-time which is longer causes a formidable impact on the microorganisms in the food media. To have a reliable high-voltage pulse generator, a technique of capacitor discharge was employed. Four units of capacitor rated 100 μF 1.2 kV were connected in series to produce 25 μF 4.8 kV which were used to store the energy of approximately 200 J. The energy stored was discharged via HTS 181-01-C to the load in the range of nano to microseconds of pulse duration. The maximum voltage applied was limited to 4 kV because it is a lab-scale project. The electrical circuit diagram and the development procedure, as well as experimental results, are presented.

With the increasingly extensive and in-depth applications of all solid-state high-voltage nanosecond pulse generators in the defense and industrial fields, the development of traditional pulse generators faces many key issues, such as high-voltage drive isolation, compact design, and reduced weight. Hence, a novel circuit topology for a self-triggered high-frequency nanosecond pulse generator is proposed. Through high potential energy-gaining technology of the interstage capacitance, this generator does not need a complicated metal–oxide–semiconductor field-effect transistor isolation drive circuit, and there are also no switching dynamic and static voltage equalization problems. This kind of generator is very suitable for compact assembly with only a single external gate driver. High voltage output can be realized by quantizing multilevel module stacking according to actual needs. At the same time, the generator has a high repetition rate and long life. The characteristic parameters of the 20-stage superposition experimental prototype are as follows: an output voltage amplitude of 15.3 kV with a rising time of approximately 45 ns, a repetition rate of 10 kHz in the pulse train, and a pulsewidth of 200–1000 ns.

A modular solid-state pulse generator based on a multi-turn linear transformer driver (LTD) is designed for the application of pulse power techniques with a high voltage, large current and wide pulse width. The LTD adopts the method of multi-turn winding on the magnetic core, which can help to output pulses of wide width. The isolation of the power supply with windings in the same direction of the LTD modules is designed, and the isolation voltage of the magnetic cores is the working voltage of the LTD modules. A modular solid-state pulse generator based on the multi-turn LTD is developed, which is composed of 10 LTD modules. Each module consists of 18 energy storage capacitors, metal-oxide-semiconductor field-effect transistors and their driving circuits connected in parallel. The pulse generator can output pulses with parameters including a voltage ranging from 0 to 5000 V, a pulse current up to −500 A, and a pulse width ranging from 200 ns to 5 μs. When all modules work in synchronisation, rectangular pulses can be produced with a rise time of 30 ns and a fall time of 16 ns. If all modules are asynchronised, trapezoidal pulses are produced with adjustable step-like rising and falling edges. Moreover, a higher-voltage pulse can be achieved by increasing the number of LTD modules.

An in-depth circuital analysis of an energy-efficient high peak power impulse radio ultra-wideband (IR-UWB) pulse generator monolithic microwave integrated circuit (MMIC) design is presented. The proposed IR-UWB pulse generation process is explained in detail. A trade-off between the peak output power level and the frequency of operation is discussed. The proposed circuit is optimised for the highest possible peak output power in the 3–5 GHz UWB band for ranging and radar application. The presented IR-UWB pulse former makes use of the cascode heterojunction bipolar transistor (HBT) configuration for signal scaling operation instead of the common emitter configuration. The proposed cascode pair configuration results in higher output voltage swing as well as reduced power consumption. The effect of coupling capacitors on amplification factor of the pulse former stages as well as impedance profile of the distributed transmission line is discussed in great detail. The temperature-dependent parasitic component in the proposed circuit is studied. Its effect on the transient behaviour of the proposed IR-UWB pulse generator is analysed, which is important for IR-UWB beamforming applications. The required mathematical model for the parasitic effect is derived and explained.

The irreversible electroporation with microsecond electric pulses is a new ablation technique adopted in the tumor therapy worldwide. On the other hand, the nsPEF (nanosecond pulsed electric field) has been proved to provide a means to induce immunogenic cell death and elicits antitumor immunity, which is under intensive in-vitro and in-vivo studies and in clinical trials. Normally, one needs two different types of electric pulse generators for producing the pulses in the ranges of nanosecond and microsecond, respectively. In order to realize these two types of tumor treatments in complementary and optimize electrical pulse parameters, we have developed a compact high-voltage pulse generator with a wide pulse width tuning range, based on a capacitor discharging configuration digitally controlled by a silicon carbide MOSFET switching array through a pair of optic-coupler drivers. The developed digital pulse generator is capable of adjusting: pulse width over 100-100 μs, voltage over 0-2 kV and repetition rate up to 1.2 kHz. The pulse generator is designed in simulation, implemented and verified in experiments. The pulse generator is shown to deliver a complementary treatment on Murine melanoma B16 cell lines, i.e., triggering the cell early apoptosis under the 300 ns pulse stimulation while a complete killing under the 100 ns pulses. The pulse generator is further demonstrated to induce antitumor immunity in a preliminary in vivo study on the mice model.

The result of the effect of stress-pulse regulation on the process of manual arc welding with the connection of pulse generator is presented. Technology of stress-pulse regulation is accessible and easy to use: the equipment is so small that it can be applied in any convenient place. At the same time, there is a practical alignment of the microhardness of the zone of the base metal of the welded plates, the transition zone and the zone of the weld, which indicates the absence of residual stresses of the welded parts. The results of the research confirm the effectiveness and prospects stress-pulse regulation in any production.

In this brief, a fully digitized pulse generator with programmable pulse number and width is used as an ultrawideband (UWB) pulse transmitter with 17.7-dBm output power for see-through-wall (STW) radar. A fully differential operation broadband CMOS power amplifier (PA) with a power-switchable mode and fast settling time for pulse radar is presented, achieving excellent power consumption, considerable output power, and a −3-dB bandwidth from 3.6 to 6.6 GHz. The on-chip transformer is used for impedance transformation in the output and converting signals from the differential to single ended. Fabricated in a 65-nm standard CMOS process, the operating carrier frequency range of the transmitter covers 3.2–5.8 GHz and the pulsewidth can be adjusted from 0.75 to 1.2 ns. The number of pulses varies from 4 to 1. At 10-MHz pulse repetition frequency (PRF), the maximum peak-to-peak voltage of the transmitter output pulse reaches 3.8 V with 50- $\Omega $ load, and the corresponding pulsewidth is 0.75 ns. The equivalent power is 17.7-dBm after calibration, and the average power consumption is only 22.5 mW.

Dielectric barrier discharge (DBD) can produce a large amount of active particles and has many applications in the industry. In order to study the effect of different rising edges, falling edges, and waveform voltages on DBD, a novel all-solid-state bipolar multilevel high-voltage pulse generator is proposed. Compared with other topologies, the proposed system can achieve more levels of waveforms with fewer switches. This article introduces the structure and working principle of the system in detail. Through PSPICE simulation, it is found that the capacitance of the switch junction will generate prepulse for the output. To solve this problem, an improved control strategy is proposed. Finally, a nine-level test prototype is built, which can work steadily under different loads. Meanwhile, different types of output waveforms are allowed to be generated when the control is adjusted. Finally, the main circuit uses 20 power switches and nine energy storage capacitors and this system can achieve a maximum output voltage of ±4 kV, adjustable frequency, and a total of 19 level voltage output (including 0 level).

This brief presents a cost-efficient all-digital CMOS digital-to-time converter (DTC) that innovatively applies binary-weighted pulse expansion. The DTC consists of a pulse generator (PG) for pulse generation ( $t_{p}$ ), a binary-weighted pulse-expanding circuit (BWPEC) as a main circuit for digital-to-time conversion, and a time subtractor (TS) for $t_{p}$ removal. Compared with the original pulse-expanding unit (PEU), a novel PEU with reduced complexity and a linear pulse expansion was developed for binary-weighted operation. The use of the BWPEC with the binary-weighted PEUs exhibits lower circuit complexity and considerably reduces the circuit cost compared to the original unary-weighted pulse-expanding circuit (PEC). A prototype of the 4-bit all-digital DTC was fabricated using a Taiwan Semiconductor Manufacturing Company (TSMC) 0.35- $\mu \text{m}$ CMOS process. The fabricated DTC exhibited an area of 0.02 mm2 achieving twofold improvement considerably. The measured resolution was approximately 5 ps, with the integral nonlinearity being −1.2–1 least significant bit (LSB). Without requiring an advanced CMOS process, the pulse variation technique with a simple structure can easily achieve fine resolution. The DTC features cost-efficient pulse expansion with binary weights and low circuit complexity.

XRAM (MARX spelt back words) is currently a very important circuit for high current pulse generators. In our previous studies, an XRAM-like circuit was proposed based on multiple pulse transformer modules and a capacitor connected in parallel. Compared with the traditional XRAM circuit, the same number of inductive energy storage modules can be used to generate higher current pulses. This circuit is also capable to recover the residual energy and generate repetitive high-current pulses. However, this circuit topology requires more power electronic switches (three IGBT switches per pulse transformer module). In order to reduce the number of switches, by adding two IGBT switches in the capacitor module, a new modular XRAM-like circuit with reduced switches (one IGBT switch per pulse transformer module) is proposed in this paper. The change of the circuit topology makes the capacitor discharge the primary inductors of the pulse transformer in series during the residual energy recovery stage, instead of the parallel discharge in the previous circuit. This requires the closing time of the IGBT switch in each pulse transformer module ahead of the discharge start time of the capacitor. Working process of the proposed circuit was described in detail and simulations of a 12-module circuit were carried out to verify the circuit operation. Finally, the preliminary experimental results of a two-module laboratory prototype are presented. The results confirm the theoretical analysis and show the validity of the converter scheme.

A novel type of highly efficient conditional feedthrough pulse-triggered flip-flop (P-FF) is proposed and demonstrated. The data-to-output (D-to-Q) delay in this circuit was highly optimized using predischarging and conditional signal feedthrough schemes. Power consumption was also reduced using a shared pulse generator and an output feedback-controlled conditional keeper, which diminished the floating status of the internal node. The driving strength of this design was further enhanced by including an additional pull-down path at the output node. Various postlayout simulation results applied to 16-nm FinFET technology demonstrated a higher energy efficiency (at all input data toggle rates) for the proposed topology than comparable P-FF devices. Notably, the proposed model achieved a 62% D-to-Q delay reduction, compared to a transmission gate FF, outperforming the device by more than 66% in terms of power efficiency and 87% in energy efficiency (at a 50% input data toggle rate). Improvements were even more significant in comparison with other conventional P-FFs. These results suggest the proposed design to be a viable new option for high-efficiency sequential elements in high-speed applications.

A significant advantage of fiber-optic sensors (FOS) over electrical sensors is their absolute indifference to the effects of electromagnetic interference. However, the high noise level of the low-intensity flux of high-energy photons in the measuring paths of analog FOS limits the accuracy of measuring devices based on them. The fact is that the analog modulation of any parameter in a FOS ultimately leads to fundamentally low-precision measurements of the degree of modulation of the intensity of the optical flux. The way out of this situation is the rejection of the analog and the transition to discrete modulation principles in the FOS of the optical flow parameters. To this end, in the modulation process, new parameters, additional to optical but not optical, are introduced into the optical flow, which will play the role of information carriers. This approach retains all the advantages of fiber optics (the optical stream remains the carrier of information), and transfers the problem of measurement accuracy to other, non-optical areas where it is properly solved. The possibility of constructing precision accelerometers (gravimeters) with measuring transducers based on new-class FOS with pulse modulation of the optical flux intensity (IFOS) is considered. The sensitive element of such an IFOS is a conical pendulum, on the basis of a cantilever mounted piece of quartz optical fiber, on the free end of which there is an inertial mass. High values of the metrological parameters of the accelerometer based on the IFOS are ensured by the possibility of precise measurements of the temporal parameters of the sequence of optical pulses generated by it. The processing of signals from the IFOS is carried out by methods and means of digital technics, which eliminates the possibility of introducing a signal processing error and allows purposefully correct the measurement results. Thanks to this, it is possible to neutralize the influence on the measurement results of both the natural flaws and imperfections of the IVOD, as well as the errors of their manufacture and adjustment. The study of the mathematical model of IFOS with real values of its design parameters and the frequency of the generator of counting pulses confirmed the possibility of obtaining high values of its metrological characteristics: the threshold sensitivity is up to 10-13 g, and the dynamic range of the measured accelerations is up to 109. These figures should be considered as illustrative. The principle of construction of the IFOS design makes it possible to easily change its metrological parameters over a wide range by a corresponding change in both the parameters of the elements of its construction and the frequency of the counting pulse generator.

Nanosecond pulse discharge plasma has many prospects in industrial applications, and high-voltage repetitive nanosecond pulse generators with compact design and light weight have become one of the key issues limiting its development in some applications. This paper presents a high voltage series-connected silicon carbide (SiC) metal-oxide -semiconductor field effect transistor ( MOSFET s) module which can be served as the main switch in a repetitive high-voltage nanosecond pulse generator. This kind of series-connected MOSFET s module with only single external gate driver requiring very few components is very suitable for compact assembly. By analyzing the working principle, three topologies of series-connected MOSFET s module are proposed. The switching behaviors of the three different topologies with four SiC MOSFET s series-connected are compared experimentally. The variation of switching characteristics of series-connection SiC MOSFET s module with different numbers of devices are investigated. The layout is also optimized to shorten pulse front time and improve output pulse quality. Furthermore, a 10 kV SiC MOSFET s module with a turn- on transition time ∼10 ns is developed. The double pulse test result demonstrates excellent switching performances. Finally, a compact and high-voltage pulse generator composed of three 10 kV SiC MOSFET s module is tailored, with a typical rise time ∼40 ns and peak voltage of ∼30 kV.

We propose and study a scheme of a microwave pulse generator operating in the frequency ranges near 37 and 73 GHz, in which the electron interaction with both the (−1)st harmonic of the counterpropagating TM02 mode and the synchronous slowed-down TM01 mode is combined in a sectionalized slow-wave system with an average diameter of 2.5λ. An efficient current modulation at the input of the slow-wave system is ensured in the region of the cathode–anode gap and the matching section, which reduces the diffraction loss of the energy flow directed towards the cathode. Numerical modeling shows that the efficiency of converting the electron-beam power to microwave radiation is up to 50%. Experiments demonstrate a stable regime of generation of subgigawatt pulses at an efficiency of more than 40% in the upper part of the millimeterwavelength range, which have a reproducible spatial wave structure corresponding predominantly to the TM01 mode at the input of the emitting horn.

Marx generators are widely used to produce transient high-voltage pulses. The evolution of semiconductor devices and power electronics concepts promotes the development of solid-state Marx generators (SSMGs) and enables them with flexible pulse modulation ability. First, this article sorts out the evolution of SSMGs topologies chronologically. We can see that how the energy efficiency of SSMGs is considerably improved by replacing resistors with diodes and switches and how square-wave pulses are generated by SSMGs based on half-bridge structures. Unipolar and bipolar pulses can be easily produced with different SSMGs. Second, we discuss the influence of rated voltage and rated power of present semiconductor switches on the performances of SSMGs since switches are the key components in pulse generators. To reduce the size and weight of SSMGs, metal–oxide–semiconductor field-effect transistors (MOSFETs) and insulated gate bipolar transistors (IGBTs) with small packages are preferable. Third, synchronous isolated driving of switches as the crucial technique in SSMGs is introduced. Different methods of providing synchronous signals and isolated power to various stages in SSMGs are illustrated. Fourth, the performance including load capacity, droop compensation, waveform modulation, and self-triggering of SSMGs is discussed. In the end, the developing trend of SSMGs is given.

ObjectiveThis article presents a novel transcranial magnetic stimulation (TMS) pulse generator with a wide range of pulse shape, amplitude, and width.ApproachBased on a modular multilevel TMS (MM-TMS) topology we had proposed previously, we realized the first such device operating at full TMS energy levels. It consists of ten cascaded H-bridge modules, each implemented with insulated-gate bipolar transistors, enabling both novel high-amplitude ultrabrief pulses as well as pulses with conventional amplitude and duration. The MM-TMS device can output pulses including up to 21 voltage levels with a step size of up to 1100 V, allowing relatively flexible generation of various pulse waveforms and sequences. The circuit further allows charging the energy storage capacitor on each of the ten cascaded modules with a conventional TMS power supply.Main resultsThe MM-TMS device can output peak coil voltages and currents of 11 kV and 10 kA, respectively, enabling suprathreshold ultrabrief pulses (> 8.25 μs active electric field phase). Further, the MM-TMS device can generate a wide range of near-rectangular monophasic and biphasic pulses, as well as more complex staircase-approximated sinusoidal, polyphasic, and amplitude-modulated pulses. At matched estimated stimulation strength, briefer pulses emit less sound, which could enable quieter TMS. Finally, the MM-TMS device can instantaneously increase or decrease the amplitude from one pulse to the next in discrete steps by adding or removing modules in series, which enables rapid pulse sequences and paired-pulse protocols with variable pulse shapes and amplitudes.SignificanceThe MM-TMS device allows unprecedented control of the pulse characteristics which could enable novel protocols and quieter pulses.

In complementary metal–oxide–semiconductor (CMOS) logic circuits, the main design requirement for low-power applications is to reduce the power dissipation. Dynamic power dissipation occurs in clock network which contributes up to 30–45% of total power dissipation of circuit mostly because of flip-flop are being used for sequencing which consumes lot of power therefore to reduce the power consumption flip-flop are being replaced with pulsed latch circuit with feedback. Conditional circuit is used in bidirectional shift register with bidirectional pulsed latch circuit. When it is compared with master–slave flip-flop, power reduction is 38%. Modified circuit is being implemented in 28 nm CMOS technology.

In this study, radio over fiber (RoF) communications systems are analyzed. In system design, optical source, pulse generator, modulator, optical fiber, optical add drop multiplexer (OADM), amplifier and filter are utilized as communication system components. In this study, performances of various pulse generators are analyzed by OptiSystem 7.0 simulation software. Radio over fiber systems with various pulse generators are modeled and the effects of them on system performance are evaluated.

We propose a technique for generating millimeter-wave radar waveforms using edge-triggered pulse generator circuits. By synchronizing the chip rate to the oscillation frequency of a binary control signal, a phase shift is introduced in the generated pulses. This way, the millimeter-wave signal can be phase-modulated without the need of additional circuit elements. We show that high-resolution radar waveforms with low range side lobes can be generated with this technique. Using brute-force optimization, we evaluate all possible sequences up to a sequence length of 25 chips and identify optimal waveforms for each length. Optimal sequences with the energy centered at zero delay and side lobes not exceeding unity are presented. The optimized waveforms are measured and verified using an in-house resonant tunneling diode (RTD) metal-oxide-semiconductor field-effect transistor (MOSFET) pulse generator. The matched filter response of the optimal waveforms is reproduced closely in the measurements. The results enable increased sensitivity in radar systems using coherent millimeter-wave pulse generators for low power applications, as for instance, radar gesture recognition in handheld devices. Using pulsed millimeter-wave radar systems with low duty cycles, continuously running oscillators can be avoided and systems with ultra-low power consumption are possible. (Less)

Purpose The pulse line ion accelerator (PLIA) is a low-cost accelerator concept originally designed to accelerate heavy ions. Our group has been investigating the use of PLIA to accelerate light ions and believe a multi-stage PLIA could be useful for short half-life PET isotope production. The goal of this work was to develop a single prototype fast PLIA structure and demonstrate electromagnetic wave propagation using a high-voltage pulser. Materials and methods A 1.6 m fast PLIA structure (wave speed > 107 m/s) was constructed along with a high-voltage, sinusoidal pulse generator. The latter uses capacitive voltage doubling and spark gap switching. A step-up transformer couples voltage from the pulser to the PLIA coil. Voltage measurements on the coil were made in air using a high-voltage resistive probe, while capacitive probes placed along the length of the PLIA were used to measure wave propagation with the PLIA structure filled with transformer oil. Results Voltage measurements acquired on the primary and secondary coils of the transformer coupler in air demonstrated a peak-to-peak voltage step-up of 4.2 relative to the pulser DC charging voltage. The maximum voltage time-rate-of-change on the PLIA coil was 0.76 × 1013 V/s. Capacitive probe measurements indicated voltage oscillations on the PLIA coil with half-period equal to 43 ± 0.9 ns and wave speed (with oil) of 1.2 × 107 m/s. Average and peak accelerating gradients were conservatively estimated to be 0.44 and 0.60 MV/m, respectively, with a charging voltage of 55 kV. Wave propagation was demonstrated at these gradients without flashover at a vacuum pressure of 9 × 10-6 Torr. Submerging the pulser in oil would allow for charging voltages up to 150 kV and produce accelerating gradients >1.2 MV/m. Conclusions Use of a multi-stage, fast PLIA for light ion acceleration could provide a low-cost complement to cyclotrons for the production of short half-life isotopes used for PET imaging, including carbon-11, nitrogen-13, oxygen-15, and fluorine-18.

In order to overcome the limitations of the existing classical and solid-state Marx pulse generators, this paper proposes a new modular multilevel voltage-boosting Marx pulse generator (BMPG). The proposed BMPG has hardware features that allow modularity, redundancy, and scalability as well as operational features that alleviate the need of series-connected switches and allows generation of a wide range of pulse waveforms. In the BMPG, a controllable, low-voltage input boost converter supplies, via directing/blocking (D/B) diodes, two arms of a series modular multilevel converter half-bridge sub-modules (HB-SMs). At start up, all the arm's SM capacitors are resonantly charged in parallel from 0 V, simultaneously via directing diodes, to a voltage in excess of the source voltage. After the first pulse delivery, the energy of the SM capacitors decreases due to the generated pulse. Then, for continuous operation without fully discharging the SM capacitors or having a large voltage droop as in the available Marx generators, the SM capacitors are continuously recharged in parallel, to the desired boosted voltage level. Because all SMs are parallelly connected, the boost converter duty ratio is controlled by a single voltage measurement at the output terminals of the boost converter. Due to the proposed SMs structure and the utilization of D/B diodes, each SM capacitor is effectively controlled individually without requiring a voltage sensor across each SM capacitor. Generation of the commonly used pulse waveforms in electroporation applications is possible, while assuring balanced capacitors, hence SM voltages. The proposed BMPG has several topological variations such as utilizing a buck-boost converter at the input stage and replacing the HB-SM with full-bridge SMs. The proposed BMPG topology is assessed by simulation and scaled-down proof-of-concept experimentation to explore its viability for electroporation applications. - 1986-2012 IEEE. Manuscript received June 12, 2018; revised October 23, 2018 and December 29, 2018; accepted February 5, 2019. Date of publication February 18, 2019; date of current version August 29, 2019. This work was supported by the Qatar National Research Fund (a member of the Qatar Foundation) under NPRP Grant 7-203-2-097. Recommended for publication by Associate Editor J. Clare. (Corresponding author: Mohamed A. Elgenedy.) M. A. Elgenedy is with the Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow G1 1RD, U.K., and also with the Department of Electrical Engineering, Faculty of Engineering, Alexandria University, Alexandria 21544, Egypt (e-mail:,mohamed.elgenedy@strath.ac.uk). Scopus

In the practical operation of an electromagnetic pulse (EMP) simulator, the flashover phenomenon on the edge of polypropylene dielectrics dominates the insulation failure mode of a peaking capacitor. To analyze the characteristics of polypropylene film flashover voltage under high-pressure SF6, an experimental platform was established, and the pulse generator could output a pulse with a rise time of approximately 27 ns. The experiments were performed on finger electrodes, and the SF6 pressure was set from 0.1 to 1.0 MPa. The experimental results show that the relationship of flashover voltage and gas pressure could be divided into two regions: in low-pressure regions, the flashover voltage increases with the gas pressure linearly and in high-pressure regions, the growth of flashover voltage gradually slows down and approaches a saturation value. As the gap distance increases, the saturation point of gas pressure decreases, and even when close to 0.4 MPa, with a 9-mm gap distance, this unconventional phenomenon cannot be ignored, particularly in practical EMP simulators. When the high surface resistivity and the charge trap distribution on the polypropylene film are considered, the accumulation and emission of surface charges on the film might be the primary reason for the saturated phenomena.

A new joining process, named high speed circular hemming (HSCH) is presented. The metal sheet is positioned on a pressure chamber and austenitized. The electrical energy stored in a pulse generator is suddenly discharged between the electrodes submerged in a fluid such as water and initiated a shock wave in the fluid. The shock wave propagates through the fluid and forms the austenitized sheets to the die cavity and creates a joint between them. The joining process is performed within a few microseconds without any phase transformation in the sheet during forming. Immediately after forming, the joint area directly quenches by the water and takes a martensitic microstructure with high strength. To investigate the capabilities of the presented method, the HSCH process was applied for the joining of 0.5 mm thickness AISI1070/AISI1070 and AISI1070/AA3105 sheets. The metallurgical and mechanical properties of the joints were investigated by optical microscopy, shear test, and peel test. According to the accomplished results, the utilization of this joining process increases the shear strength and energy absorption capacity of the joint.

In the application of pulsed-power technology, capacitive loads require that high-voltage pulses have fast front and back edges. Using multiple semiconductor switches, insulated gate bipolar transistors (IGBTs) in series with discharge high-voltage capacitors can generate high-voltage pulses. By adding a group of truncation switches, square pulses with fast back edges can be obtained. A novel drive circuit using many transformers with their primary windings in series is proposed to generate two groups of reverse driving signals by changing the dotted terminals on the secondary sides. The dead time between these signals is realized by adding some time-delay circuits. In terms of drive control, both the discharging switches and the truncation switches are triggered synchronously since the primary windings of all transformers are connected in series, which ensures the synchronism of driving signals. Time-delay drive circuits are added to the secondary sides of transformers to ensure a proper dead time between the two groups of driving signals for both discharging and truncation switches. Moreover, all driving power is provided from the single driver on the primary side, greatly simplifying the drive circuit. The voltage balancing of cascade IGBTs is realized by using resistor–capacitor–diode (RCD) snubber circuits. Experiments were carried out over resistive and capacitive loads. Square pulses with a voltage amplitude of 10 kV, a pulsewidth of $8~\mu \text{s}$ , a rising time of 157 ns, and a falling time of 78 ns were obtained on a 20- $\text{k}\Omega $ resistive load. The voltage amplitude, pulsewidth, and frequency are continuously adjustable.

A system for excitation of coherent oscillations of a bunch of particles was created to study the beam dynamics at the VEPP-4M electron-positron collider; it consisted of a pulse generator, a beam deflection device (kicker), and a control and synchronization system. The system has two independent channels for the excitation of horizontal and vertical oscillations and makes it possible to excite oscillations of a given bunch of particles. For observations of beam oscillations, a system for measuring the position of the beam in the reverse mode is used, as well as a fast multichannel photomultiplier tube (profilometer). The design and results of operation of high-voltage nanosecond shock generators with a current pulse duration of 200–250 ns at the base, a voltage up to 25 kV and a current up to 2 kA are described. Using constructive solutions, the durations of the fronts of the output pulses were reduced, which made it possible to avoid the excitation of neighboring bunches. Testing the generators for their working loads gave the following results: a horizontal impact pulse of 30 ns and a vertical impact of 50 ns, a horizontal impact pulse tip duration of ~20 ns, a maximum pulse amplitude of 25 kV, and a time instability (jitter) of ±1 ns. The results of measurements of the beam parameters obtained using this system are presented.

The traveling-wave Marx generator was first proposed by Carl Baum to analyze the switch-closure propagation process in fast pulsed-power systems. To improve the performance of the transistorized sub-nanosecond pulse generator, the traveling-wave Marx circuit with inter-stage transmission lines is studied. Simulations indicate that the delay time and the impedance of inter-stage transmission lines [microstrip lines on printed circuit board (PCB)] are main factors affecting the pulse waveform. Based on it, the series connection of modularized Marx circuits is proposed, which has the advantages of adjustable amplitude and bendable circuit layout. A compact high-amplitude pulse generator is developed with the amplitude of 8.2 kV, the rise time of 150 ps, and the PCB length of 35 cm. For higher pulse repetition rate, the heat dissipation design of PCB is necessary; however, due to the variations in the microstrip line structure, the commonly used metallic heat sink may cause a significant decrease in pulse amplitude. Thus, a novel heat dissipation design is proposed by optimizing the layout of metallic sinks and introducing heat-conducting ceramic sinks. A high-repetition-rate pulse generator is developed with the maximum pulse repetition rate of 600 kHz, the amplitude of 1.1 kV, and the rise time of 160 ps.

An understanding of the electrostatic interaction between charged electrical conductors embedded in a grounded cylinder is quite useful in the design of compact pulse generators. We get the complete solution for capacitance between the two spheres and the capacitance between the sphere and the grounded cylinder in series form. The dependence of these capacitances on various geometrical parameters is very useful in the design phase of Marx generators where the stray capacitances play crucial roles.

Purpose. Comparison of electrical circuits of experimental plants for obtaining micro- and nanosecond discharges in gas bubbles in water and comparing the experimental results obtained for disinfecting water using such discharges . Methodology. To obtain high-voltage pulses on the load in the form of a gas bubbles and a layer of water with a frequency of more than 2000 pulses per second, a method of generating micro- and nanosecond pulses using high-voltage pulse generators based on a pulse transformer (PT) according to Tesla, with a transistor opening switch IGBT in the low-voltage part of the circui . A current-limiting resistor with a resistance R cl = 24 kW is used to protect the transistor switch at microsecond discharges. At nanosecond discharges, a multi-gap spark gap is used to sharpen the front of high-voltage pulses. We used a capacitive voltage divider with a division factor of K d = 7653 to measure voltage pulses, a shunt with a resistance of R s = 2.5 W for measuring current pulses. RIGOL DS1102E digital oscilloscope with a 100 MHz bandwidth was used as a recording device . Results. The effect of micro- and nanosecond discharges in gas bubbles on microorganisms was experimentally investigated. It was possible to reduce the biochemical oxygen consumption of water during microsecond discharges, reduce the turbidity of water, and improve its organoleptic qualities. The energy released in a single pulse with microsecond discharges W µ ≈ 17 mJ, with nanosecond discharges W n ≈ 7.95 mJ. At nanosecond discharges, complete inactivation of E.coli bacteria was achieved. The disinfecting and purifying action of nanosecond pulses is better compared to microsecond pulses due to an increase in the amplitude of the pulsed voltage up to 30 kV, and a pulsed current of up to 35 A. Originality . The possibility of effective microbiological disinfection of water using nanosecond discharges in gas bubbles at low specific energy consumption has been experimentally shown. Practical value. The obtained experimental results on water disinfection using micro- and nanosecond discharges offer the prospect of industrial application of installations using such discharges for disinfecting and purification wastewater, swimming pools, and post-treatment of tap water.

The development of new methods and high-bit instruments for measuring phase shifts of high-frequency periodic signals with high speed for radar and radionavigation tasks is an actual task. The purpose of this work is to create a new phase shift meter for high-frequency periodic signals based on the double-matching method using direct digital frequency synthesis.On the basis of the proposed mathematical model of phase shift measurements of periodic signals by the method of double coincidence using the statistical accumulation of pulse coincidences, a functional diagram of a digital phase shift meter of periodic signals using a direct digital frequency synthesizer is developed. This allowed the implementation of an 8-bit converter phase shift signal to the code on the programmed logic integrated circuit EPM240T100C5N firm Altera.The digital phase shift meter of periodic signals based on the double-matching method consists of two comparators, two short-wave pulse generators, a direct digital frequency synthesizer, two pulse counter control circuits, two short pulse coincidence circuits, two pulse counting circuits, four clock counters, four registers, a microcontroller and an indicator. Block diagram of a double-matching digital phase meter using direct digital sintesizer use minimal hardware logic.In the developed phase shift meter, due to the use of the double-matching method, the time delay between signals does not depend on the period of input signals and can be found when changing the frequency of periodic pulses in wide limits. Measurement errors will be determined mainly by the duration of the pulses of coincidence. The use of statistical accumulation of pulse coincidence in the basis of the work allowed eliminating the restrictions on the duration of pulses of known non-ionic meters.On the basis of the obtained results, a high-bit converter of phase shifts of high-frequency periodic signals into a binary code with high speed for problems of industrial tomography, radar and radionavigation can be developed.

In this paper, a modular topology is presented for generating high-voltage pulsed power. The proposed structure consists of Marx-type modules, which are based on the switched-capacitor (SC) concept. This module receives an input voltage and, depending on the requirement of the user, produces an output voltage either equal to the input or twice as much as the input voltage, which shows the flexibility of our model. The capability of the module to produce a doubled output makes it appropriate for applications with low input voltage sources. Also, the topology has the capability of generating combined wide and narrow pulses. The topology was simulated in MATLAB Simulink and a laboratory setup was built to test its operation. The results validate the theoretical basis of the structure.