Rise time

About: Rise time is a research topic. Over the lifetime, 4748 publications have been published within this topic receiving 47512 citations.

Picosecond pulse generator using delay lines

Abstract: A passive circuit built with either high-quality coaxial cable of microstrip delay lines can convert a step signal with 25 ps rise time, from a conventional time-domain reflectometer, into a rectangular pulse of duration in the 50 ps-500 ns range, a separate delay line circuit being required for each pulse duration, The system provides an excellent probing signal for single rectangular pulse testing of analog pulse-shaping circuitry built to operate in the 2 Mb/s to 20 Gb/s range. >

Microwave High-Speed Liquid Crystal Devices Using CPW with Floating Electrode

Abstract: We develop a transmission line with a floating electrode (FE) arranged on a coplanar waveguide (CPW), and we propose using this transmission line to reduce the decay time of a microwave-band liquid crystal loaded device. Using the proposed CPW-FE structure makes it possible to control both the rise time and decay time by varying the applied bias field, thereby allowing the decay time to be reduced. In the 18 GHz band variable phase shifter we developed, we obtained a rise time of 75 ms and a decay time of 200 ms with a 500 μm wide CPW center conductor, a gap of 20 μm between the center conductor and ground plane, and a liquid crystal layer thickness of 50 μm. Under these conditions, the birefringence Δϵ′ of the liquid crystal was 0.23.

40 GW Linear Transformer Driver stage for pulse generators of Mega-ampere range

Abstract: Linear transformer driver (LTD) technology is actively developed at the Institute of High Current Electronics in Tomsk, Russia This technology is being examined for use in high current high voltage pulsed accelerators Recent development of high voltage low inductance capacitors and low inductance switches enabled to achieve ~100 ns rise time of the LTD output pulse This technique allows one to eliminate intermediate pulse forming sections, used in the present accelerator technology, which would keep the footprint of an LTD accelerator small LTD based drivers are currently considered for many applications, including future very high current Z-pinch drivers for inertial confinement fusion, medium current drivers with adjustable pulse length for isentropic compression experiments, and finally relatively low current accelerators for radiography and X-pinches In this article, we present the design and test results for a new LTD stage, that operates at 100 kV charging voltage Current amplitude up to 850 kA with ~140 ns rise time was obtained on a 005 Ω load Stack of the LTD stages can be easily assembled in series or in parallel, thus providing voltage or current multiplication, respectively Design of multi-mega-volt and multi-mega-ampere generators becomes straightforward with the LTD technology

Picosecond Electro-Optic Sampling

Abstract: The electro-optic sampling technique is a new characterization technique based on short optical pulses (picosecond or femtosecond) and the electro-optic effect. With this technique, electrical waveforms have been characterized with temporal resolution of less than 300 fs, corresponding to a 1 THz bandwidth. Since its inception in 1982, this method has been adapted to a variety of measuring situations, leading to a large number of embodiments. The electro-optic sampling was first used to study the dispersion of picosecond electrical pulses on transmission lines. Using a superconducting transmission line, it has been recently shown that conduction losses can be defeated’and single picosecond pulses propagated over a few millimeters. Additionally, Ultrafast transistors have been tested with single picosecond resolution that is, the transistor response was time-resolved as the gate was pulsed using a step function with a picosecond rise time. MESFET, TEGFET, and permeable base transistor (PBT) responses have been studied, and switching times as low as 5 ps have been directly measured for the PBT. Because GaAs exhibits the Pockels effect, the GaAs components and circuits can be directly probed in a noninvasive way. We will review the principle of electro-optic sampling in its various embodiments and applications to device and circuit characterization, as well as the direct investigation of velocity overshoot and ballistic and resonant tunneling transport.

Evaluation of dynamic performance of pressure sensors using a pressure square-like wave generator

Abstract: In this study, we measured the dynamic characteristics of pressure sensors using a pressure square-like wave generator (PSWG). With high excitation energy, the PSWG can measure dynamic pressure and work more effectively in a high frequency range. Under the same experimental parameters (10 bar, 600 Hz), the performance of six pressure sensors of dissimilar design and structure was evaluated. The experimental results indicate that they all exhibited extremely different dynamic characteristics. The dynamic pressure sensors based on quartz plates and crystals possess larger overshoot, greater gain margin and shorter rise time in comparison with other sensors based on strain gauge and piezoresistive materials. Compared with other traditional methods, such as the hydraulic control method, the PSWG proves to be superior in that it can be employed to evaluate the dynamic performances of pressure sensors at high frequency of above 10 kHz.