Step Recovery Diode Research Articles

Direct transient co-simulation of a Step Recovery Diode (SRD) Pulse Generator

Direct transient co-simulation of a Step Recovery Diode (SRD) Pulse Generator

Modeling and Jitter Improvement of SRD-Based Ultra-Wideband Pulse Generator

Step recovery diode (SRD)-based ultra-wide band (UWB) pulse generators (PGs) suffer from jitter caused by AM-to-PM conversion, SRD shot noise, and clock jitter. These noise sources significantly impact the accuracy of UWB systems if very high precision ranging/positioning is required. Jitter behavior caused by the transmitter and receiver is mostly detrimental in the equivalent time-sampling receiver. Thus, a mathematical model for simulation of the jitter and amplitude variation effect in the equivalent time-sampling technique has been developed and used in SystemVue simulations. A criterion as an estimate of system accuracy is defined as signal-to-distortion ratio (SDR) and used. Similarly, a model for AM and PM noise analysis for an SRD-based UWB PG is developed that was validated experimentally. In addition, SRD shot-noise contribution on output jitter was evaluated using the proposed model. Based on these models, methods to reduce the output jitter of the system have been recommended. Simulation showed that clock jitter and SRD shot noise led to pronounced output jitter, with shot noise the primary cause. For a typical SRD-based UWB PG, an output jitter of around 3 ps has been achieved using improvement techniques based on the proposed method, compared to a 15-ps jitter before improvement. These measured results are in good agreement with our predictions.

Low‐ringing and reduced‐cost step recovery diode based UWB pulse generators for GPR applications

ABSTRACTLow‐ringing and reduced‐cost pulse generators for ultrawideband applications using step recovery diode (SRD) have been reported in this article. The circuits generate Gaussian pulses of 170 ps pulse width and a minimal ringing of −22 dB and monocycles of 401 ps duration and high fractional bandwidth of 162%. Cost‐reduction is mainly attributed to the resistive attenuator and single SRD used. Negligible change in circuits' performance was witnessed for repetition rate from 1 to 100 MHz which makes it apt for low to medium range ground penetrating radar applications. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2289–2294, 2014

A Novel Subnanosecond Monocycle Pulse Generator for UWB Radar Applications

A novel ultra-wideband (UWB) monocycle pulse generator with good performance is designed and demonstrated in this paper. It contains a power supply circuit, a pulse drive circuit, a unique pulse forming circuit, and a novel monopolar-to-monocycle pulse transition circuit. The drive circuit employs wideband bipolar junction transistors (BJTs) and linear power amplifier transistor to produce a high amplitude drive pulse, and the pulse forming circuit uses the transition characteristics of step recovery diode (SRD) effectively to produce a negative narrow pulse. At last, the monocycle pulse forming circuit utilizes a novel inductanceLshort-circuited stub to generate the monocycle pulse directly. Measurement results show that the waveform of the generated monocycle pulses is over 76 V in peak-to-peak amplitude and 3.2 ns in pulse full-width. These characteristics of the monocycle pulse are advantageous for obtaining long detection range and high resolution, when it is applied to ultra-wideband radar applications.

100 ps Optical pulse generator using laser diodes for visible light communication applications

ABSTRACTWe present a simple ultrashort optical pulse generator based on step recovery diode, short‐circuited transmission line and relaxation oscillation effect suppression with reduced dc bias. Experimental results achieved a 80‐ps optical pulse with 655 nm AlGaInP laser diode (LD) and a 200‐ps optical pulse with 420‐nm GaN‐based LD. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:185–187, 2014

Pulse Power Nanosecond-Range DSRD-Based Generators for Electric Discharge Technologies

New design of power nanosecond-range generators for electric discharge in gases is described. These generators are based on semiconductor opening switches-Drift Step Recovery Diodes (DSRD). The main advantages of DSRD are very short switching-off time (<;3 ns), high commutated power (>500 kW for single DSRD with 2 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of semiconductor structure), and high reliability of high voltage stacks consisting of many connected in series DSRD. The experimental results of DSRDbased generator application for ozone production and waste gas cleaning are presented. The main parameters of the generators: output pulse voltage up to 36 kV, pulse rise time <;4 ns, pulse repetition rate up to 3.5 kHz, output pulse power >4.5 MW.

A simple sub-nanosecond ultraviolet light pulse generator with high repetition rate and peak power

We present a simple ultraviolet sub-nanosecond pulse generator using commercial ultraviolet light-emitting diodes with peak emission wavelengths of 290 nm, 318 nm, 338 nm, and 405 nm. The generator is based on step recovery diode, short-circuited transmission line, and current-shaping circuit. The narrowest pulses achieved have 630 ps full width at half maximum at repetition rate of 80 MHz. Optical pulse power in the range of several hundreds of microwatts depends on the applied bias voltage. The bias voltage dependences of the output optical pulse width and peak power are analysed and discussed. Compared to commercial UV sub-nanosecond generators, the proposed generator can produce much higher pulse repetition rate and peak power.

Design and implementation of a hybrid digital and RF front-end module for 24-GHz intelligent transport system pulse-doppler radar

This article presents a hybrid digital and RF front-end module (FEM) of a 24-GHz pulse-Doppler radar system for intelligent transport system applications. The conventional pulse generators use analog components such as step recovery diode. It is difficult to control the parameters of the pulse. In addition, the heterodyne architecture based transceivers show good performance, but they are very expensive. To overcome these limitations, a digital pulse generator was developed based on field-programmable gate array platform to obtain high degree of freedom in a waveform design. Instead of the heterodyne architecture, a transceiver based on the homodyne architecture was developed. For the first time, hybrid digital FEM based 24-GHz pulse-Doppler radar was developed by combining a digital pulse generator and a homodyne-based transceiver. Experimental results showed the feasibility of using a hybrid digital FEM for a 24-GHz pulse-Doppler radar. The developed hybrid digital FEM contributes to the advancement of the digital radar field. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1631–1638, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27666

Balanced pulse generator for ultra‐wideband radar application

A balanced pulse generator with high voltage amplitude and pulse width in the picoseconds region is described. It can operate well at the pulse repetition frequency (PRF) up to 500 kHz. The proposed generator contains four NPN silicon power transistors operating in avalanche mode and a pair of pulse shaping circuits which effectively utilise the transition characteristics of a step recovery diode. Measurement results are presented, which show the output of the generator are balanced pulses with peak values of ±46 V at 100 kHz PRF and approximately 330 ps full-width at half-maximum in width.

Superfast Drift Step Recovery Diodes (DSRDs) and Vacuum Field Emission Diodes Based on 4H-SiC

This paper presents the results of research and development of two types diode structures based on wide bandgap 4H-SiC: drift step recovery diodes (DSRDs) and field emission diodes (FED). Diodes’ structure and manufacturing methods are reviewed. Diode’s characteristics were obtained (static current-voltage characteristics and capacitor-voltage characteristic, switching properties’ characteristics for DSRDs). Field emission 4H-SiC structures illustrated high (≥102 А/сm2) current densities at electric field intensity of approximately 10V/um. 4H-SiC DSRDs in the generator structure with a single oscillating contour allowed to form sub nanosecond impulses at a load 50 Ohm and 1,5-2kV amplitude for a single diode (current density at V=2kV J= 4•103 А/сm2),what is significantly higher than similar DSRD’s parameters obtained for silicon.

Drift-Step-Recovery Diode Characterization by a Bipolar Pulsed Power Circuit

A stack of drift- step-recovery diodes (DSRDs) can produce high-voltage pulses with a rise rate of the order of 1 kV/ns. Their building blocks, i.e., the DSRD dies, are designed and manufactured at Soreq Nuclear Research Center based on silicon epitaxial layers. A characterization circuit for DSRDs is presented. The circuit features a power MOSFET, which serves to pump the DSRD in the forward direction and then to pulse it in the reverse direction, and a bias voltage source to balance the forward pumping current with respect to the reverse discharge. Placing the DSRD in series between the MOSFET and the load results in temporal and polarity separation of the MOSFET and DSRD pulses at the load, thus allowing viewing of the net DSRD signal. High-voltage probes are employed to measure the MOSFET and load voltages. Based on this measurement, we formulate the voltage and current extraction of the circuit signals. A 1-ns 190-V epi-Si DSRD die was characterized by this circuit. We show that the DSRD pulses when its reverse discharge is equal to the forward charge, as expected. The DSRD switching loss was measured. An accurate 98% energy balance, which includes the input and output energies with respect to the MOSFET and DSRD switching losses, was obtained. The relationship between the bias voltage, the pumping current, and the main supply voltage is provided. The experimental results are supported by a numerical simulation of the DSRD in the circuit using the Synopsys technological computer-aided design incorporated with a SPICE solver.

An Improved Ultra-Wideband, Ultra-Short Monocycle Pulse Generator

This paper presents an improved ultra-wideband monocycle pulse generator circuit based on step recovery diode. This pulse generator circuit uses short-circuit microstrip transmission line to generate the Gaussian pulse the monocycle pulse. The improved pulse-shaping network employs two schottky diodes and a MESFET to suppress the pulse ringing. The SRD model was built in RF simulation software ADS, and then the design and simulation of the pulse generator circuit was accomplished using this model. The experiments showed an monocycle pulse of 400ps pulse width with good symmetry. The measured results agreed with the simulation.

Installation for air cleaning from organic impurities by plasma formed by barrier discharge of nanosecond duration

A prototype installation for air cleaning by plasma, which consists of a barrier-type discharge reactor and a high-voltage nanosecond-pulse supply generator, which is based on drift step recovery diodes, is considered. A stable corona-type barrier discharge was obtained at a 3-kHz supply-pulse repetition frequency. The discharge remained nonlocalized even at a small gas-discharge gap (∼6 mm) due to a short (∼25 ns) pulse duration, which allows a quite uniform effect on the air flow. The high rise rate (∼6 kV/ns) of the applied supply voltage pulses determines the high voltage amplitude (∼25 kV) at the reactor at the breakdown moment and allows maintenance of high electric-field intensity and a high intensity of plasma chemical processes. Thus, an electrical power lower than 8 W is required at the reactor input to produce 1 g of ozone per hour. The concentration of methylmercaptan in air during waste-water smell deodorizing at State Unitary Enterprise “Vodokanal of St. Petersburg” was reduced down to an allowable level of 0.5 mg/m3 at the electrical power consumption no higher than 0.25 W per cubic meter of air.

Subnanosecond 4H-SiC diode current breakers

Mesa epitaxial 4H-SiC-based p +-p-n 0-n + diodes have been fabricated and their reverse recovery characteristics have been measured in modes typical of fast semiconductor current breakers, drift step recovery diodes, and SOS diodes. It has been found that, after the short (∼10 ns) pulsed injection of nonequilibrium carriers by a forward current with a density of 200–400 A cm−2 and the subsequent application of a reverse voltage pulse (with a rise time of 2 ns), diodes can break a reverse current with a density of 5–40 kA cm−2 in a time of about (or less than) 0.3 ns. A possible mechanism for ultrafast current breaking is discussed.

A High-Performance Low-Ringing Ultrawideband Monocycle Pulse Generator

In this paper, a performance-enhanced ultrawideband monocycle pulse generator circuit using a step recovery diode is designed and tested. Factors that could cause pulse waveform distortions are analyzed. By applying an attenuator and a simple yet effective pulse-shaping circuit, the impedance matching between the pulse generator and the oscillator source is considerably improved, and a quality monocycle pulse is generated with small ringing and leveraged amplitude. Measured results validate the design.

METHOD OF ELECTROMAGNETIC PULSE ULTRA WIDEBAND PROBING OF THE UNDERLYING MEDIUM

A method for subsurface EMP UWB probing, using different DSRD (drift step recovery diodes) generators for the emission of electromagnetic waves, is described. More depth of the signal propagation is based on the manifestation of the low-frequency dispersion of the dielectric constant of the medium, which is due to the presence of induced polarization with the dipole relaxation mechanism, describing the behavior of wet soil under the influence of a strong electromagnetic pulse field. The article describes methods for solving the inverse problem of the depth and a comparison of EMP UWB probing predictions ahead of tunnels with the results of direct tunneling

Model and simulation of a new ultra-narrow trigger frequency alterable pulse generator

Two new kinds of ultra-narrow trigger frequency alterable picosecond pulse generator are presented. One can produce positive pulses and the other can produce negative pulses. The two pulse generators are subdivided into three parts: signal driving circuit, differentiator network and pulse shaping circuit. The pulse shaping circuit is made of step recovery diode (SRD) and short-circuit microstrip line. A positive pulse with width of 54 ps (50%–50%), rising time of 30 ps (10%–90%) and falling time of 32 ps (90%–10%), and a negative pulse with width of 54 ps (50%–50%), rising time of 30 ps (90%–10%) and falling time of 30 ps (10%–90%) are achieved in simulation. All of the components are ready-made and inexpensive. They can be applied in ultra-wideband (UWB) communication system, such as transmitters and receivers.

Subnanosecond Pulse Generators for Impulsive Wireless Power Transmission and Reception

This brief describes a novel impulsive wireless power transmission (WPT) and reception system. This new concept enhances the power conversion efficiency (PCE) for low average input power. Low input power is important in several applications, such as biomedical implant devices and energy harvesting from unknown sources. An ultrawideband (UWB) monocycle pulse generator is designed using a shunt step recovery diode. The fabricated pulse generator produces an impulse width of approximately 290 ps. Complete wideband transmitting and receiving systems are implemented to validate the feasibility of impulsive WPT technologies and to assess the improvement of the conversion efficiency of the rectifier circuitry. Finally, UWB impulsive wireless transmission systems demonstrate 59.6% PCE, even when the input power of the rectifier is less than - 2.84 dBm.

지반투과 레이더 시스템을 위한 SRD 임펄스 발생기 및 안테나의 설계 및 제작에 관한 연구

In this paper, a ground penetrating radar(GPR) system is implemented for landmine detection. The performance of the GPR system is associated with the characteristics of local soil and buried target. The choice of the center frequency and the bandwidth of the GPR system are the key factors in the GPR system design. To detect a small and shallow target, the higher frequencies are needed for high depth resolution. We have been designed, fabricated and tested a new impulse generator using step recovery diodes. The measured impulse response has an amplitude of 6.2V and a pulse width of 250ps. The implemented GPR system has been tested real environmental conditions and has proved its ability to detect a small buried target.

Note: Picosecond impulse generator driven by cascaded step recovery diode pulse shaping circuit

In this paper, a picosecond impulse generator using step recovery diodes (SRDs) is presented. In order to reduce the pulse width of an impulse generator, we employed a cascaded SRD pulse-shaping circuit. A short impulse generation is confirmed in numerical simulation of a time-transient circuit simulator. Measurements show that the measured pulse width of the cascaded SRD impulse generator is 250 ps at 10% of the peak amplitude, which is improved by 85 ps compared with a conventional SRD impulse generator.