Rise time

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

Plasma source with segmented magnetron cathode

Abstract: A sputtering apparatus includes a chamber, an anode, a cathode assembly comprising target material, and a magnet. A platen supports a substrate. A power supply is electrically connected to the cathode assembly and generates a plurality of voltage pulse trains comprising at least a first and a second voltage pulse train. The first voltage pulse train generates a first discharge that causes sputtering of a first layer of target material having properties that are determined by at least one of a peak amplitude, a rise time, and a duration of pulses in the first voltage pulse train. The second voltage pulse train generates a second discharge from the feed gas that causes sputtering of a second layer of target material having properties that are determined by at least one of a peak amplitude, a rise time, and a duration of pulses in the second voltage pulse train.

A Sub-Picosecond Resolution 0.5–1.5 GHz Digital-to-Phase Converter

Abstract: A digital-to-phase converter (DPC) is an essential building block in applications such as source-synchronous interfaces and digital phase modulators. The resolution of DPCs using analog phase interpolators is severely affected by the operating frequency and rise times of the interpolator inputs. In this paper, we present a new DPC architecture that achieves high resolution independent of both the operating frequency and the rise time. The 8 phases generated by a phase-locked loop are dithered using a delta-sigma modulator to shape the truncation error to high frequency and is subsequently filtered using a delay-locked loop phase filter. The test chip, fabricated in a 0.13 mum CMOS process, operates from 0.5 -1.5 GHz and achieves a differential nonlinearity of less than plusmn0.1 ps and an integral nonlinearity of plusmn12 ps. The total power consumption while operating at 1 GHz is 15 mW.

Effects of propagation on the rise times and the initial peaks of radiation fields from return strokes

Abstract: The theoretical solution to the problem of radiation from a pulsed vertical dipole over a flat homogeneous earth is employed to study the changes in rise times and the attenuation of the initial peaks of the radiation fields from lightning constructed according to the most recent experimental data on lightning return stroke radiation fields Expected changes in rise times and the attenuation of the initial peaks for different values of distances and conductivities are presented It is shown that for a given initial rise time there is a spread in distant rise times due to the variability of the shapes of the radiation fields The expected spread in distant rise times for different values of distances and conductivities is calculated The results show the importance of taking into account the propagation effects in any attempt to estimate return stroke current parameters such as rise time, rate of rise, and peak current from radiation fields which propagated over land The predictions are compared with the available experimental data, and a good agreement is found between them

Robot gripper control system using PVDF piezoelectric sensors

Abstract: A novel robot gripper control system is presented that uses PVDF (polyvinylidene fluoride) piezoelectric sensors to damp exerted force actively. By monitoring the current developed by the PVDF sensor, an output proportional to the rate of change of the force exerted by the gripper is obtained. The signals from the PVDF sensor and strain-gauge force sensor are arranged in a proportional and derivative control system for the control of force. The control system was tested on an instrumented Rhino XR-1 manipulator hand. The capabilities of the control system are analyzed and are verified experimentally. The results for this particular gripper indicate that the additional sensory feedback can decrease the force step response rise time by 88% while maintaining a monotonic zero-overshoot response. The inclusion of the rate feedback increases the damping ratio of the dominant poles while maintaining the step response rise time. >

Emission-Decay Curves, Energy-Transfer and Effective-Refractive Index in Gd2O3:Eu3+ Nanorods

Abstract: Cubic Gd2O3:Eu3+ (0.30, 1.01, 2.78, and 4.60 mol %) nanorods with an average diameter of ca. 14 nm were synthesized at ambient pressure and mild temperature (70 °C), using a simple and cost-effective wet-chemical route. The emission-decay curves of the 5D1 and 5D0 levels, hereafter referred to as 5D1(C2) and 5D0(C2), were investigated. Although the decay time of the 5D0 level of the Eu3+ ions residing in the C2 site of cubic Gd2O3:Eu3+ nanostructures were previously reported, little is known about the rise time component in the 5D0 emission-decay curve and the energy-transfer pathways responsible for it. The 5D0(C2) rise time and the 5D1(C2) decay time exhibit similar and strong dependence on the Eu3+ concentration and temperature. The 5D1(C2) decay time matches well the rise time extracted from the rising component of the 5D0(C2) emission-decay curve. The decay time of the 5D0(C2) level (ranging from 1.4 to 2.1 ms, depending on the filing factor of the nanorods) is longer than that of the bulk counterpar...