Electronic amplifier with power supply switching Patent
Increasing power conversion efficiency of electronic amplifiers by power supply switching
Kramer, M.↗
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Electronic amplifiers: A compilation
Several types of amplifiers and amplifier systems are considered. These include preamplifiers, high power amplifiers, buffer and isolation amplifiers, amplifier circuits, and general purpose amplifiers.
Source record↗
Polarographic carbon dioxide transducer amplifier
Electronic amplifier contains matched pair of metal oxide semiconductor field effect transistor devices which have high input impedance and long-term stability. Thermistor in feedback loop provides temperature compensation for large drifts in the sensor.
Stillman, G.↗
Ultra small electron beam amplifiers
Data on field emission and microfabrication technologies relevant to the development of low-power electron-beam amplifiers and oscillators are discussed. The fabrication of a thin-film field-emission (TFFE) cathode for a 1-W electron-beam amplifier is examined. Some TFFE cathodes have been developed and tested in electron guns. Recent experimental results reveal that a beam can be formed from the field-emission cathode, and the TFFE cathode is applicable for devices operating below 3 kV at currents of less than 20 mA. The use of microfabrication techniques to construct slow-wave circuits is studied, and the use of finned structures as the slow-wave circuit for an electron-beam oscillator or amplifier is proposed.
Dayton, J. A., Jr.↗
Gated amplifiers for data processing in space
Electronic amplifier for data processing in space
ELECTRONIC AMPLIFIER↗
Integrated Strategies for Overcoming Resolution Limits in Electron Beam Lithography of Chemically Amplified Resists
Electron beam lithography (EBL) of chemically amplified resists (CARs) faces fundamental challenges, including stochastic electron scattering and acid diffusion, that limit resolution and reproducibility. Using SU-8 as a model CAR, this study systematically investigated complementary strategies to address these challenges, combining multipass exposure, proximity effect correction (PEC) with midrange correction factors, base quencher incorporation, and post-exposure bake (PEB) suppression. Monte Carlo simulations and calibrated PEC modeling revealed that extending the point spread function to include a midrange scattering component significantly improved critical dimension (CD) control across varying pattern densities, correcting deviations that conventional two-term PEC failed to capture. Multipass exposure, particularly 4-pass writing with a 25% offset, redistributed the dose to average stochastic beam and scattering fluctuations, reducing line-width roughness by more than 50% and yielding more uniform nanoscale features. Photoacid confinement was investigated by adding urea as a base quencher, which successfully reduced acid diffusion but introduced substantial sensitivity penalties without improving ultimate resolution or Z-factor performance, underscoring the trade-offs of chemical versus physical confinement. Suppressing PEB most directly minimized acid diffusion, resulting in improved Z-factors and reproducible 30 nm half-pitch dense line/space patterns. Overall, these results demonstrated that PEC with midrange correction, multipass strategies, quencher additives, and PEB-free processing addresses different aspects of the EBL process window and that their integration provides a comprehensive framework for managing stochastic scattering, diffusion, and chemical amplification effects. This framework advances dense nanoscale patterning in CARs and establishes guiding principles for optimizing resist design and process strategies in high-resolution EBL and potentially other advanced lithographies, such as extreme ultraviolet (EUV) lithography.
36 MATERIALS SCIENCE↗
Specification and Design of the SBRC-190: A Cryogenic Multiplexer for Far Infrared Photoconductor Detectors
Arrays of far-infrared photoconductor detectors operate at a few degrees Kelvin and require electronic amplifiers in close proximity. For the electronics, a cryogenic multiplexer is ideal to avoid the large number of wires associated with individual amplifiers for each pixel, and to avoid adverse effects of thermal and radiative heat loads from the circuitry. For low background applications, the 32 channel CRC 696 CMOS device was previously developed for SIRTF, the cryogenic Space Infrared Telescope Facility. For higher background applications, we have developed a similar circuit, featuring several modifications: (a) an AC coupled, capacitive feedback transimpedence unit cell, to minimize input offset effects, thereby enabling low detector biases, (b) selectable feedback capacitors to enable operation over a wide range of backgrounds, and (c) clamp and sample & hold output circuits to improve sampling efficiency, which is a concern at the high readout rates required. We describe the requirements for and design of the new device.
Erickson, E. F.↗
Stable amplifier having a stable quiescent point Patent
Development of stable electronic amplifier adaptable for monolithic and thin film construction
Kleinberg, L. L.↗
Coherent Control over Nuclear Hyperpolarization Using an Optically Initializable Chromophore-Radical System
Chromophore radicals (CR) are emerging as important components for molecular quantum information science (QIS), especially in the context of quantum sensing. Here, we demonstrate that the optically hyperpolarized electrons in a 1,6,7,12-tetrakis(4-tert-butylphenoxy)-perylene-3,4,9,10-bis(dicarboximide) (tpPDI) covalently linked to a partially deuterated 1,3-bis(diphenylene)-d 16 -2-phenylallyl radical (BDPA-d 16 ) can be coherently manipulated via pulsed dynamic nuclear polarization (DNP) methods to transfer polarization to nuclear spins and back. Under light illumination at 85 K, electron hyperpolarization in BDPA is enhanced 2.1- to 2.4-fold over thermal polarization and lasts for more than 100 ms. By applying nuclear orientation via electron spin-locking (NOVEL) DNP, this optically amplified electron hyperpolarization was successfully transferred to a 1 H nuclear spin within the CR system and efficiently returned to the electron spin for readout via reverse-NOVEL. The NOVEL transfer efficiency of 65% amounts to a 688-fold nuclear spin hyperpolarization of the target nuclear spin, considering the 2.1-fold electron spin hyperpolarization. This reversible coherent manipulation of hyperpolarization transfer highlights the utility of CR systems to initialize and read out nuclear spin states in a disordered matrix at moderate cryogenic temperatures. Coupled with CRs’ environmental compatibility, tunability, and precise state initialization, these results highlight the promising role of nuclear spins in CRs for QIS applications, including quantum sensing and memory.
charge transfer↗
Development of a radiation-hard photomultiplier tube
In a radiation-hard photomultiplier tube (PMT) such as has been developed for stabilization of the Galileo spacecraft as it goes through the Jovian high energy radiation belts, the primary effects of high energy electron and proton radiation that must be resisted are the production of fluorescence and Cerenkov emission. The present PMT envelope is ceramic rather than glass, and employs a special, electron-focusing design which will collect, accelerate and amplify electrons only from desired photocathode areas. Tests in a Co-60 radiation facility have shown that the radiation-hard PMT produces less than 2.5 percent of the radiation noise of a standard PMT.
Birnbaum, M. M.↗
Amplifier drift tester
Automatic measuring and recording of gain and zero drift characteristics of electronic amplifier
Cree, D.↗
Very high resolution radiometer
A primary sensor used in environmental and earth-resource observation, the Very High Resolution Radiometer (VHRR) was designed for use on the ITOS D series spacecraft. The VHRR provides a 0.47 mile resolution made possible with a mercury-cadmium-telluride detector cooled to approximately 105 K by a passive radiator cooler. The components of this system are described. The optical subsystem of the VHRR consists of a scanning mirror, a Dall-Kirkham telescope, a dichroic beam splitter, relay lenses, spectral filters, and an IR detector. Signal electronics amplify and condition the signals from the infrared and visible light detector. Sync generator electronics provides the necessary time signals. Scan-drive electronics is used for commutation of the motor winding, velocity, and phase control. A table lists the performance parameters of the VHRR.
Aronson, A. I.↗
Progress of analog-hybrid computation
Review of fast analog/hybrid computer systems, integrated operational amplifiers, electronic mode-control switches, digital attenuators, and packaging techniques
ELECTRONIC SWITCH↗
Brushless DC motor with dual windings
Motor has high starting torque and high running speeds. Control system consists of Hall effect generator/resolver and associated electronic amplifiers and switches. Motor operation is described.
Auclair, G. F.↗
Experimental Study of Airfoil Trailing Edge Noise: Instrumentation, Methodology and Initial Results
The mechanisms of aerodynamic noise generation at the trailing edge of an airfoil is investigated. Instrumentation was designed, a miniature semiconductor strain-gauge pressure transducer and associated electronic amplifier circuitry were designed and tested and digital signal analysis techniques applied to gain insight into the relationship between the dynamic pressure close to the trailing edge and the sound in the acoustic far-field. Attempts are made to verify some trailing-edge noise generation characteristics as theoretically predicted by several contemporary acousticians. It is found that the noise detected in the far-field is comprised of the sum of many uncorrelated emissions radiating from the vicinity of the trailing edge. These emissions appear to be the result of acoustic energy radiation which has been converted by the trailing-edge noise mechanism from the dynamic fluid energy of independent streamwise 'strips' of the turbulent boundary layer flow.
Manley, M. B.↗
Plasma double-layers produced by ponderomotive force
Non-linear rectification of the RF electric fields excited in a convectively amplifying electron beam-plasma interaction results in a dc electric field, and a corresponding ponderomotive force acting on the charged particles to produce a space-charge separation, i.e. a type of plasma double-layer. This paper analyses the effect, taking into account plasma electron temperature and electron-neutral collisions. To measure such double-layers, an electron beam probe constitutes a convenient non-perturbing diagnostic technique, but great care is required in its calibration. An analysis is presented taking into account significant non-linear effects which had been neglected in previous work. The paper concludes with some preliminary experimental results illustrating the use of the technique in a beam-plasma interaction for which a weak double-layer electric field is predicted.
Levine, J. S.↗
Optical Link For Readout From Focal-Plane Array
Outputs of photodetectors modulate beam of light. Proposed optical link carries analog readout signals from photodetectors in focal-plane array to external signal-processing circuitry. Insensitive to electromagnetic interference at suboptical frequencies, and imposes smaller heat load on cryogenic apparatus because it does not include high-power electronic amplifier or laser transmitter within cold chamber.
Fossum, Eric R.↗
A Hot-wire Circuit with Very Small Time Lag
A circuit for a hot-wire anemometer for the measurement of fluctuating flow is presented in the present report. The principal elements of the circuit are a Wheatstone bridge, one branch of which is the hot wire; and an electronic amplifier and a current regulator for the brief current which in combination maintain the bridge balance constant. Hence the hot wire is kept at practically constant resistance and temperature, and the time lag caused by thermal inertia of the wire is thereby reduced. Through the addition of a nonlinear amplifying stage the reading of the instrument has been rendered proportional to the velocity. A discussion of certain characteristics of the circuit and the results of related calibrating tests are given.
Weske, John R↗