List of electrical engineers

Akira Koyano is an Aloka coauthor of the 1985 real-time blood flow imaging paper with Chihiro Kasai, Koroku Namekawa and Ryozo Omoto. A particularly clear test in that paper moved a thread around motor-driven pulleys in a water tank and compared its speed with the velocity-calculator output.^[ref]

The thread makes the moving target controllable independently of a patient's circulation. For a simplified Doppler ultrasound calculation,where $f_0$ is transmitted frequency, $v$ target speed, $\theta$ the angle to the beam and $c$ sound speed. With stipulated $f_0=3\mathrm{MHz}$, $v=0.20\mathrm{m}{\mathrm{s}}^{-1}$, $\theta =60{}^{\circ }$ and $c=1500\mathrm{m}{\mathrm{s}}^{-1}$, the predicted shift is $400\mathrm{Hz}$. These are illustrative inputs, not a reproduction of a particular plotted data point.

A speed sweep at fixed geometry tests one part of the signal chain. An angle error changes the projection even if the frequency estimate is exact; changing target material can change echo strength. Bench agreement therefore supports the tested motion-to-output relation while leaving separate questions about scattering, anatomy and clinical interpretation.

Koroku Namekawa is an Aloka coauthor of the 1985 Color Doppler imaging paper with Chihiro Kasai, Akira Koyano and Ryozo Omoto. Their instrument combined pulse-echo acquisition with complex correlation processing; the paper reports experiments with moving targets and flowing water.^[ref] The shared authorship establishes his participation; it does not assign each circuit or experiment to one coauthor.

A useful engineering constraint is the acquisition-time budget. If an image has $N$ beam directions, each uses $n$ pulses separated by $T$, and overhead is ignored, its acquisition time is approximatelyFor an original example, $N=50$, $n=8$ and $T=0.20\mathrm{ms}$ give $t_{\mathrm{frame}}=0.080\mathrm{s}$ and $F=12.5$ frames per second. Doubling the ensemble to 16 pulses halves that ideal rate. These stipulated values illustrate the timing constraint, rather than a performance specification of Namekawa's instrument.

Longer averaging can improve a noisy autocorrelation estimate while reducing temporal coverage or image rate. It cannot create time that was not available between transmitted pulses. Thus a blood flow image is the outcome of both an estimator and a scanning schedule, not a simultaneous velocity observation at every displayed pixel.

Chihiro Kasai is the first named author of the 1985 paper on real-time blood flow imaging with autocorrelation, coauthored with Koroku Namekawa, Akira Koyano and Ryozo Omoto. The original paper identifies Kasai with Aloka and presents an estimator suited to repeated ultrasound echoes.^[ref]

The computational idea can be seen without reproducing the instrument. For an ideal complex echo sequence $z_n=A{e}^{in\varphi }$, multiplying by a complex conjugate givesAveraging such products estimates the phase increment rather than requiring a complete spectrum at every image location. This is Lag-one Doppler phase estimation. With stipulated pulse spacing $T=0.25\mathrm{ms}$ and increment $\varphi =\pi /4$, the corresponding Doppler effect frequency shift is $f_D=\varphi /(2\pi T)=500\mathrm{Hz}$. The convention assumes increasing complex phase for a positive shift.

Only the phase modulo $2\pi$ is observed. The same sequence results from $f_D+m/T$ for any integer $m$, so the calculation alone cannot select the physical frequency outside a chosen unambiguous interval. This is aliasing, not evidence that the scatterer has reversed direction. The example exposes a measurement limit of the phase estimator independently of any diagnostic interpretation.

Mike Beckman is an electrical engineer identified in a 2013 Texas Instruments reference design as a systems engineer who, at that time, managed its converter product line. With Luis Chioye, he coauthored Precision Thermocouple Measurement with the ADS1118 by Mike Beckman and Luis Chioye, combining an analog-to-digital converter, thermocouple input and on-chip temperature sensor.^[ref]

Their design treats cold-junction compensation as both an electrical calculation and a thermal-layout problem. It places the converter near the connector and uses copper regions to improve cold-junction thermal coupling, while separating nearby heat sources. Its tests distinguish changing the reference-junction temperature from changing the measuring-junction temperature.^[ref]

A simple original linear model illustrates the reason. If a thermocouple has stipulated sensitivity $S=40\mu V/K$ and measures $V=2\mathrm{mV}$, then $V=S(T_h-T_c)$ implies $T_h-T_c=50\mathrm{K}$. A reference junction at $25{}^{\circ }\mathrm{C}$ therefore gives $T_h=75{}^{\circ }\mathrm{C}$. Reading that junction as $30{}^{\circ }\mathrm{C}$ instead gives $80{}^{\circ }\mathrm{C}$, despite perfect measurement of $V$. The model uses constant sensitivity only for illustration; actual cold-junction compensation uses the appropriate thermoelectric conversion.

Luis Chioye writes about precision analog-to-digital converters and their measurement circuits. The author biography in a 2013 Texas Instruments reference design identifies him as an applications engineer in its Precision Analog group, with degrees in electrical engineering from the University of Arizona and Walden University/NTU School of Engineering and Applied Science.^[ref]

His work includes ratiometric measurement with resistance thermometers: sharing an excitation electric current can cancel its variation, but the input and reference filters must preserve that shared variation consistently.^[ref] This is the engineering distinction captured by ratiometric cancellation with matched signal and reference filters.

With Mike Beckman, Chioye also published a thermocouple reference design. Its reference-junction temperature sweep in thermocouple testing keeps the measurement junction in a stable bath while changing the temperature of the connector and converter board; the acquisition computer stays outside the temperature-controlled chamber. This isolates reference-side effects from changing the temperature being measured.^[ref]

An original ideal calculation explains the test. Let $E(T)$ be the thermocouple electromotive force response from the Seebeck effect relative to $0{}^{\circ }\mathrm{C}$. With isothermal connector junctions at $T_c$, the measured electric potential difference is $V=E(T_h)-E(T_c)$. Cold-junction compensation reconstructs $E(T_h)=V+E(T_c)$ before applying the inverse function of the response. In the stipulated linear model $E(T)=ST$ with $S=40\mu V/K$, a fixed $T_h=100{}^{\circ }\mathrm{C}$ gives $V=3.2\mathrm{mV}$ at $T_c=20{}^{\circ }\mathrm{C}$ and $2.8\mathrm{mV}$ at $30{}^{\circ }\mathrm{C}$. Correct compensation gives the same $100{}^{\circ }\mathrm{C}$ in both cases. These are constructed values, not measured performance or a calibration table for a particular thermocouple.

Cold-junction thermal coupling matters because the temperature sensor must represent the connector temperature. A precise converter reading cannot by itself remove an unmeasured temperature difference between those locations.^[ref]

Joseph Wu is the named author of Texas Instruments' 2018 guide to resistance thermometer measurements, revised in 2023. The guide connects sensor wiring, excitation electric current, reference resistors and analog-to-digital converters rather than treating the converter as a complete thermometer by itself.^[ref]

One concrete design distinction is between two-wire resistance measurement and four-terminal sensing. In the two-wire arrangement, the same leads carry excitation electric current and contribute to the measured electric potential difference. Their electrical resistance is therefore counted with the sensor. Separate sense leads with high input impedance can exclude that series drop, although input leakage and other nonidealities still require attention.^[ref]

For an original ideal example, let a sensor have electrical resistance $R_T=100\Omega$, with two $1\Omega$ leads carrying $I=1\mathrm{mA}$. Two-wire resistance measurement givesThe $2\Omega$ lead error remains even when a shared reference resistor cancels excitation variations in the ratiometric measurement. Ideal four-terminal sensing instead measures $I{R}_T=100\mathrm{mV}$ directly across the sensor. This illustrates the platinum resistance thermometer lead resistance error mechanism without assuming a particular resistance-to-temperature calibration.

A proposed bench comparison replaces the sensor with a stable calibrated resistor and adds known series resistors to its current leads. Comparing two-wire and four-terminal sensing readings then tests lead-drop rejection without changing sensor temperature. The calculation distinguishes the wiring error from sensor self-heating in a ratiometric resistance measurement, which changes the sensor's actual electrical resistance.

Hector Hernandez is the credited presenter and preparer of the TI Precision Labs training material Brushed DC Motor 2: The H-Bridge by Hector Hernandez. Its scientific subject is the H-bridge: a switching network that applies either polarity to a motor and provides paths for the electric current already stored in the inductive load. The primary title slide gives his name exactly as used here.^[ref]

The material connects a controller's commands to MOSFET gate drive, then distinguishes forward/reverse conduction from recirculation. That distinction matters because reversing a command does not instantaneously reverse the electric current in a motor's inductance. Slides 5–7 show electric current decay paths through diodes or conducting switches.^[ref]

For an original bridge-loss example, take a $12\mathrm{V}$ supply and a stated operating electric current of $2\mathrm{A}$ through two conducting switches, each with electrical resistance $0.05\Omega$. Their combined conduction loss isand their combined potential drop is $2IR=0.20\mathrm{V}$. The motor terminals receive $11.8\mathrm{V}$ in the chosen conducting state, giving $23.6\mathrm{W}$ of electrical input from $24\mathrm{W}$ supplied. This is not a calculation of mechanical output: motor winding loss, induced electric potential difference and mechanical losses remain separate.

A bench comparison records terminal electric potential difference and motor electric current together while changing the bridge state. The waveforms separate voltage reversal from electric current reversal and expose the recirculation interval discussed in the training material. The numerical values above are illustrative calculations, not performance measurements attributed to Hernandez.

Daniel J. Carnovale is an electrical engineer associated with investigating and demonstrating the behavior of electric power systems. His coauthored Capacitor Application Issues by Thomas M. Blooming and Daniel J. Carnovale identifies his Eaton affiliation; its author biography describes a demonstration and test facility for reproducing electrical supply problems and evaluating their mitigation.^[ref]

One important distinction in power factor correction is between reduced source electric current and reduced useful-load active power. For an original idealized example, a load takes $P=1000\mathrm{W}$ and $Q=750\mathrm{var}$ at $V=200\mathrm{V}$ RMS. Before correction,Canceling the fundamental reactive power makes source electric current $I_1=P/V=5\mathrm{A}$, but leaves the stipulated load's $1000\mathrm{W}$ unchanged. With a fixed upstream electrical resistance of $0.2\Omega$, conductor Joule heating falls from $7.8125$ to $5\mathrm{W}$. The reduction is $2.8125\mathrm{W}$, rather than 20% of the load's active demand.

A proposed demonstration measures load active power, source RMS electric current and upstream conductor loss separately while connecting the correction branch. It makes the changed and unchanged quantities visible. The same input-output discipline applies when comparing a device's apparent electrical savings with useful service delivered. The numerical example above is an original fixed-boundary calculation, not a measurement attributed to Carnovale.

His paper with Thomas M. Blooming places such calculations within practical capacitor application. Choosing a nominal correction alone does not describe how variable load and the existing network affect operation. The distinction motivates recording terminal waveforms and operating conditions along with a single power factor number.

Thomas M. Blooming is an electrical engineer whose coauthored Capacitor Application Issues by Thomas M. Blooming and Daniel J. Carnovale addresses practical use of capacitor banks in electric power systems. Its author biography describes work on power factor correction, harmonic filtering and related application measurements.^[ref]

A useful technical question is why improving fundamental displacement power factor can alter the response to other harmonic components. In an original lossless parallel LC circuit, the admittance isIts reactive terms cancel at the resonant frequencyFor stipulated $L=10\mathrm{mH}$ and $C=100\mu \mathrm{F}$, $f_r\approx 159.15\mathrm{Hz}$. Doubling $C$ moves it to about $112.54\mathrm{Hz}$. A correction component chosen for one operating frequency has therefore changed the network at other frequencies as well.

In this ideal parallel model the impedance diverges at resonance; a finite imposed harmonic electric current would demand an unbounded electric potential difference, signaling the ideal model's limit. Real losses and other network elements bound and shift the response. A proposed bench test uses a small known drive and sweeps frequency with and without the extra capacitor, recording both current and potential difference. It tests the frequency-dependent circuit rather than inferring behavior from the fundamental cosine alone.

The calculation is an original illustration of the network question, not an experimental result attributed to Blooming. His joint paper with Daniel J. Carnovale supplies the application context: component choice and operating conditions must be considered together. A correction that looks favorable in a single-frequency power factor calculation is not, by that fact alone, characterized across the full waveform.

Jeffrey Lang is an electrical engineer whose work concerns electromechanical conversion power balance, control and small-scale devices. MIT's Research Laboratory of Electronics identifies the same professor as Jeffrey H. Lang and describes research on electric motors, electrical generators and microelectromechanical systems, together with teaching in circuits and electromagnetism.^[ref]

The identified MIT profile provides an externally hosted portrait of Jeffrey H. Lang.

For an original motor-scale illustration, a shaft delivering torque $\tau =2\mathrm{mN}\mathrm{m}$ at angular velocity $\omega =1000\mathrm{rad}{\mathrm{s}}^{-1}$ delivers $P_m=\tau \omega =2\mathrm{W}$. If electrical input is $3\mathrm{W}$ and the operating point is steady, the remaining $1\mathrm{W}$ must be accounted for by losses or another specified output. During acceleration some input can instead increase rotational kinetic energy. Reporting only shaft speed would not establish either output power or conversion efficiency.

With Anant Agarwal, Lang is credited on the MIT course material State and Memory by Anant Agarwal and Jeffrey Lang. It explains how a capacitor's state summarizes the part of past input needed to predict its future response.^[ref] For a series RC circuit with a constant later input $V_f$,Two different earlier input histories that leave the same initial capacitor electric potential difference give the same subsequent response under the same future input. For stipulated $RC=1\mathrm{ms}$, $v_C(0)=1\mathrm{V}$ and $V_f=3\mathrm{V}$, the value after one time constant is $3-2/e\approx 2.2642\mathrm{V}$. This original numerical example shows what it means for the state to retain enough of the past without retaining the entire waveform.

Karl K. Berggren is an electrical engineer whose research includes superconductivity-based electrical circuits, electronic devices and single-photon detectors for quantum applications. MIT's Research Laboratory of Electronics identifies him as a professor of electrical engineering and physics and as head of its quantum nanostructures and fabrication group.^[ref] These research areas connect the behavior of very small devices to the circuits needed to read and control them.

MIT's identified faculty profile also links an externally hosted portrait of Karl K. Berggren.

His 6.200 Notes: Sinusoidal Steady State by Karl K. Berggren explain why complex numbers simplify linear differential equations driven by sinusoidal inputs. For a series RC circuit observed across its capacitor, the equation $RCd{v}_C/dt+v_C=v_{\mathrm{in}}$ gives the late-time frequency responseThe notes obtain this result by solving for a complex exponential and taking its real part.^[ref]

For an original illustration, $R=1\mathrm{k\Omega }$ and $C=1\mu \mathrm{F}$ give a time constant of $1\mathrm{ms}$. At $\omega =1000\mathrm{rad}{\mathrm{s}}^{-1}$, $H=(1-i)/2$: a one-volt peak sinusoidal input produces a $1/\sqrt{2}$-volt peak output lagging by $\pi /4$. A separate term proportional to $e^{-t/(RC)}$ is the transient and depends on the starting state. Distinguishing that term from the forced sinusoid is what makes the steady-state calculation experimentally useful. This numerical illustration applies his teaching derivation; it is not a reported device measurement.

James L. Kirtley Jr. is an electrical engineer whose work concerns electric machines and electric power systems. MIT's departmental profile identifies him as a professor emeritus of electrical engineering, with energy and robotics among his research areas.^[ref]

The engineering problem is to match a motor's behaviour to its application. MIT reported in 2016 that Kirtley worked on customized electric motors for the MIT Cheetah robot, where brief peaks of torque serve running and jumping. The same interview describes his interest in electric motors interacting with microgrids, particularly their dynamic behaviour during supply disturbances.^[ref] A short burst and sustained operation place different demands on the system; the largest instantaneous output alone does not describe its operating role.

His AC Power Flow in Linear Networks by James L. Kirtley Jr. connects the phasor representation of electric potential difference and electric current to physical energy transfer. In its peak-amplitude convention, complex electrical power is $S=V_{\mathrm{pk}}{I}_{\mathrm{pk}}^{\ast }/2$. With RMS phasors $V=V_{\mathrm{pk}}/\sqrt{2}$ and $I=I_{\mathrm{pk}}/\sqrt{2}$, this becomes $S=V{I}^{\ast }$. The complex conjugate ensures that the relative phase enters the active power.^[ref]

For an original load example in sinusoidal steady state, take $V=20\mathrm{V}$ and electrical impedance $Z=(3+4i)\Omega$, using RMS phasors and the passive sign convention: electric current enters the positive-potential terminal. A series resistor and inductor realize this model at the specified angular frequency when $R=3\Omega$ and $\omega L=4\Omega$. ThenThus active power is 48 watts, reactive power is 64 vars, apparent power is 80 volt-amperes, and power factor is $48/80=0.6$. Write $\varphi =\arctan (4/3)$ and $x=\omega t$. The corresponding electric potential difference and electric current areMultiplying and applying a trigonometric identity gives instantaneous powerIts cycle average is 48 watts, while its range is $[-32,128]$ watts. The negative portions represent temporary return of stored energy from this ideal load; the electrical resistance still dissipates a positive average. A synchronized product of the two waveforms reveals this behaviour, whereas multiplying their root mean square magnitudes gives only the apparent power.

Jan C. Willems was an electrical engineer and systems theorist whose work helped make dissipativity a general tool for studying dynamical systems. His university-hosted curriculum records an electrical-engineering doctorate at MIT in1968, a systems-and-control professorship at Groningen from1973, and later work as a guest professor at KU Leuven. It records his death on31August2013.^[ref]

His1972general theory expresses a system's balance using a storage function and supply rate. The formulation compares a change in stored quantity with integrated input supply, allowing physical energy accounting and input–output performance bounds to share one mathematical language.^[ref]

An original example illustrates the scientific idea. A2kilogram mass with viscous coefficient3newton-seconds per metre obeys $2\dot{v}=u-3v$. Its kinetic energy is $S=v^2$ joules when $v$ is expressed in metres per second, andAt constant velocity1metre per second, a3newton force supplies3watts, all dissipated while the stored kinetic energy stays1joule. The dissipativity article develops the general inequality; this simple case shows why its supply and storage terms must be distinguished.

Willems also developed behavioral systems theory, which describes a dynamical system by a family of admissible time histories. His curriculum explains the motivation: an interconnected system need not come with a uniquely privileged division into control inputs and plant outputs. Interconnection can instead impose shared variables and compatibility between trajectories.^[ref] The two contributions address complementary questions: which histories are possible, and what balance law must each history obey?

Pete Semig is an analog-electronics engineer and technical author associated with Texas Instruments. A2013 company reference design identifies his applications work on difference and instrumentation amplifiers. The same document credits Peter Semig on its title page and uses Pete Semig in its author biography.^[ref]

His current-measurement work connects a small electrical signal to an instrument's usable range. A shunt resistor produces an electric potential difference proportional to current, and an amplifier makes that difference easier to measure. The2013 reference describes a single-supply low-side current sensing design for a stated10microampere-to10milliampere range.^[ref]

For an original simplified example, choose a1ohm shunt and current $I=20\mathrm{mA}$. The shunt drop is $V=IR=20\mathrm{mV}$, and a voltage gain of50 gives a1volt output. The shunt also dissipatesThus the measurement element changes the circuit it measures, through both its voltage drop and its dissipation. An input-equivalent amplifier offset of100microvolts would correspond to0.1milliampere in this example. These selected values do not reproduce the reference design.

Semig's Integrator Circuit by Pete Semig similarly states the operating limits behind an integrating amplifier: capacitor feedback gives an ideal integral, while offsets, finite bandwidth and the DC feedback path limit practical behavior.^[ref] His technical contribution is to connect circuit equations with component choices and the conditions under which a measurement remains interpretable.

Malcolm C. Smith is a Cambridge researcher in control theory whose work connects robust control and mechanical network synthesis with physical system design. The Cambridge research profile identifies uncertainty, robustness and mechanical applications as themes of his work; the IEEE Control Systems Society independently identifies his Cambridge affiliation.^[ref]

His 2002 paper Synthesis of Mechanical Networks: The Inerter by Malcolm C. Smith introduced the inerter as a two-terminal mechanical element. Its ideal terminal force is proportional to relative acceleration,where $b$ is mechanical inertance. Both terminals can move, so equal terminal accelerations produce zero force in this ideal constitutive relation. This makes the element useful for synthesizing mechanical responses through networks, alongside springs and dampers.^[ref]

For an original ideal transmission example, relative terminal displacement drives a flywheel with angle $\theta =(x_1-x_2)/r$. With moment of inertia $J$, its kinetic energy isso equivalent mechanical inertance is $b=J/r^2$. Choosing $J=0.002\mathrm{kg}{\mathrm{m}}^2$ and $r=0.01\mathrm{m}$ gives $b=20\mathrm{kg}$. A relative acceleration $5\mathrm{m}{\mathrm{s}}^{-2}$ then gives $100\mathrm{N}$. The coefficient has mass units, but it is not a statement that the flywheel's physical mass is20kilograms.

The calculation neglects friction, compliance and transmission inertia beyond the chosen flywheel. It illustrates the design idea, not measured performance of a particular device. The IEEE Control Systems Society profile includes a labeled headshot.

Julius O. Smith III works on applications of digital signal processing to music and audio. Stanford identifies him as a professor emeritus of music and, by courtesy, electrical engineering, based at its Center for Computer Research in Music and Acoustics. His doctorate in electrical engineering was completed at Stanford in 1983.^[ref]

His Spectral Audio Signal Processing by Julius O. Smith III explains how to extract a spectral envelope rather than treating every narrow harmonic peak as part of the slowly varying sound shape. One method uses a cepstrum: transform a logarithmic magnitude spectrum, retain an appropriate low-quefrency region, and transform back. This separates broad spectral shape from more rapidly oscillating harmonic detail under suitable assumptions.^[ref]

For example, two played notes can have different harmonic spacings while sharing a similar broad envelope associated with the instrument's resonances. Distinguishing spacing from envelope helps explain why changing a note's pitch and changing its timbre are different signal-processing tasks. The separation is approximate: window choice and closely spaced spectral features affect what the method preserves.

T. Keech is credited, under that initial and surname, as coauthor with C. W. Wang of Antenna Models for Electromagnetic Compatibility Analyses by C. W. Wang and T. Keech, an October 2012 NTIA technical memorandum. The title page verifies this attribution but is not a basis for expanding the initial or choosing a portrait of a namesake.^[ref]

The report assembles antenna gains, radiation patterns and sidelobe parameters for assessing interference between radio systems. Its scientific role is to make the assumed angular concentration of radiation explicit when comparing unwanted received power between systems.^[ref]

C. W. Wang is credited by that name as coauthor with T. Keech of Antenna Models for Electromagnetic Compatibility Analyses by C. W. Wang and T. Keech. The primary title page identifies the authors and the October 2012 memorandum; it does not justify guessing a full personal name or using a portrait of another Wang.^[ref]

The report compiles radio-antenna radiation patterns, gain values and sidelobe requirements for electromagnetic compatibility studies. These inputs determine how strongly a transmitter radiates toward an unintended receiver, so using a realistic pattern can change an interference calculation even when total transmitted power is unchanged.^[ref]

Peter B. L. Meijer is a researcher whose work includes image-to-sound sensory substitution. His 1992 engineering paper described how a grayscale image could be encoded as a time-varying sound pattern.^[ref]

The design scans image columns from left to right. Horizontal position becomes time within a scan, vertical position selects an audio frequency, and brightness sets an oscillator's amplitude. For example, a bright point high on the right produces a relatively high-frequency component late in the scan. Different rows contribute superposed tones. This provides an explicit encoding whose mathematical information content can be studied separately from how well a listener learns to interpret it.^[ref]

An electrical engineer whose experiments investigated selection and recognition of simultaneous speech.

An electrical engineer whose research includes game theory and mathematical optimization.^[ref]

Homepage: asu.mit.edu/

Carl W. Helstrom developed quantum detection and estimation methods for distinguishing signals and inferring parameters in optical systems. His work asks what information a quantum measurement can extract when the field itself limits accuracy. The Helstrom-Holevo bound expresses the minimum error probability for distinguishing two specified quantum states, connecting a statistical decision problem to an optimal quantum measurement.^[ref]

Electrical engineer whose research includes nuclear magnetic resonance and dynamic nuclear polarization.^[ref]

Walt Kester is an electrical engineer whose technical writing concerns data converters and sampled-data electronics. He edited The Data Conversion Handbook edited by Walt Kester, which brings together converter architectures, testing, interfacing and practical circuit design.^[ref]

A useful distinction in this subject is between signal sampling, which selects values at particular times, and quantization, which selects a representable numerical level. An analog-to-digital converter combines both. Kester's explanation of the Nyquist–Shannon sampling theorem connects the sampling rate with the frequencies present at the converter input, making filtering part of the measurement design.^[ref]

Technical publications: www.analog.com/en/resources/technical-books/data-conversion-handbook.html

An electrical engineer who develops quantum-computing hardware.^[ref]

A physicist researching condensed matter physics.^[ref]

An electrical engineer who developed semiconductor light-emitting devices at Nichia.^[ref]

An electrical engineer researching semiconductor crystal growth and optoelectronics.^[ref]

Shuji Nakamura is an electrical engineer whose work helped make efficient blue light-emitting diodes possible using gallium nitride and indium gallium nitride. His work combined improved material growth, activation of p-type semiconductor and the design of an emitting active layer.^[ref]

One crucial result concerned hydrogen binding to magnesium acceptor impurities in gallium nitride. The resulting complexes suppress their electrical activity; thermal treatment can remove that passivation. In an emitting semiconductor heterostructure, injected electrons and holes recombine in an active layer with a smaller band gap than the surrounding material, helping confine the carriers where light is produced. This connects material chemistry with an operating electronic device.^[ref]

Hiroshi Amano is an electrical engineer whose work with Isamu Akasaki helped overcome two obstacles to blue light-emitting diodes: growing high-quality gallium nitride and obtaining controllable p-type semiconductor.^[ref]

A low-temperature-deposited aluminium nitride buffer layer improved subsequent gallium nitride growth on sapphire. His lecture compares the resulting surfaces using scanning electron microscopy. The research also showed that low-energy electron irradiation of magnesium-doped gallium nitride could activate p-type semiconductor, enabling a p-n junction. The two results address different requirements: structural quality and the electrical activity of the semiconductor doping.^[ref]

Isamu Akasaki was an electrical engineer whose research helped establish gallium nitride as a material for blue and ultraviolet light-emitting diodes. Working with Hiroshi Amano and other collaborators, he pursued improvements in crystal quality and in the control of p-type and n-type semiconductor.^[ref]

The scientific motivation follows from photon energy: shorter visible wavelengths require larger transition energies. A sufficiently wide band gap is therefore necessary for blue emission, but it does not by itself produce a useful device. The material must also support carrier injection and efficient light emission. High-quality growth and an operating p-n junction turned those physical requirements into an engineering platform for full-colour displays and lighting.^[ref]

George Alfred Hockham was an electrical engineer whose work with Charles K. Kao examined optical fibers as communication waveguides. Their 1966 paper analyzed how a dielectric core with a higher refractive index than its surroundings can guide an electromagnetic wave.^[ref]

The work treated guidance together with practical losses, bending and dispersion. A guided field alone does not specify a useful communication link: the signal must survive propagation, and different components must remain distinguishable at the receiver. Their combination of optical and microwave investigations connected the field calculation with the engineering feasibility of the transmission medium.^[ref]

Charles K. Kao was an electrical engineer whose work helped establish the feasibility of low-loss optical fiber communication. With George Alfred Hockham, he analyzed dielectric-fibre guidance at optical frequencies, including the losses and information-carrying limitations of the medium.^[ref]

The important engineering question was how to turn a physically guided mode into a practical long-distance signal path. Their analysis examined absorption, bending loss and dispersion alongside mode behaviour. This linked the electromagnetic design of a waveguide to the properties of the glass and to the timing of signals, rather than treating transparency as a sufficient description.^[ref]

An electrical engineer researching semiconductor lasers and optical fibers.^[ref]

An electrical engineer who developed integrated circuits at Texas Instruments.^[ref]

Simon van der Meer was an electrical engineer whose development of stochastic cooling made dense antiproton beams available for collider experiments. The method reduces the spread of particle motion in phase space, allowing beams produced over many cycles to be accumulated.^[ref]

A pickup senses an electrical signal from particles passing through a storage ring. After amplification and an appropriate delay, a downstream kicker applies a corrective force. The timing connects the measured deviation with the returning particles; the signal from each particle is mixed with contributions from others, so gain and noise determine the net cooling. This turns high-speed feedback electronics into a tool for controlling a particle distribution.^[ref]

Emmett Leith was an electrical engineer whose work with Juris Upatnieks developed wavefront reconstruction through a communication-theory treatment of holography. Their 1962 paper analyzed recording and reconstruction as a sequence of modulation, propagation and intensity detection, and tested methods for improving the reconstructed signal.^[ref]

The connection is useful because an intensity recording can contain information about an optical wave's phase through interference with a reference wave. Changing the recording geometry can separate the desired reconstruction from unwanted terms. Their work helped make clear three-dimensional holographic images practical while linking optical processing with spatial frequency analysis.^[ref]

Bill Pickering (rocket scientist) was an electrical engineer whose work connected electronic instrumentation with robotic space exploration. His experience designing telemetry equipment brought him to the Jet Propulsion Laboratory, where he later served as director from 1954 to 1976.^[ref]

During that period, JPL participated in the launch of Explorer 1 and developed spacecraft for studying the Moon and planets. The Ranger program returned close-up lunar images and the Surveyor program achieved soft landings. Those missions illustrate the coupled engineering problem: an instrument must make a useful measurement, and the spacecraft must control its operation and communicate the result across a large distance.^[ref]

An electrical engineer working in signal processing. ^[ref]

He authored lecture notes and transparencies. ^[ref]

An electrical engineer and coauthor of the digital optical phase conjugation experiment described there.^[ref]

Joel B. Fowler is an electrical engineer whose work at NIST included the design and characterization of a water-bath blackbody source for radiometry. His 1995 paper describes a cavity whose temperature and effective emissivity could be controlled and measured accurately.^[ref]

The apparatus placed a shaped copper cavity in a stirred, temperature-controlled water bath. The cavity geometry increases the number of internal specular reflections, raising its effective emissivity toward one, while the bath reduces temperature variation. The paper reports operation from 278 K to 353 K and calculated emissivity 0.9997, increased to 0.99997 with a restricted aperture. Geometry, thermal control and measurement uncertainty accounting therefore work together to create a useful measurement calibration source.^[ref]

Identity and discipline: upload.wikimedia.org/wikipedia/commons/7/74/A_Third_Generation_Water_Bath_Based_Blackbody_Source_(IA_jresv100n5p591).pdf

W. Marshall Leach, Jr. was an electrical engineer whose work included audio electronics, electroacoustics, electronic instrumentation and low-noise circuit design. His research and teaching connected audio power amplifiers with loudspeaker systems and acoustic measurement.^[ref]

His notes The Junction Diode by W. Marshall Leach, Jr. develop the relationship between the physical junction and the circuit models used to analyze it. That connection is useful in audio engineering as well: a model must capture the relevant device behaviour while remaining simple enough to reason about bias, signal variation and distortion.^[ref]

Identity and biography: leachlegacy.ece.gatech.edu/bio.html

An electrical engineer whose research includes optimization and control theory.^[ref]

Homepage: www.mit.edu/~parrilo/

Mario P. Vecchi is an electrical engineer whose work has included semiconductor research, broadband communications and computational optimization. With Scott Kirkpatrick and Charles Daniel Gelatt Jr., he coauthored the 1983 paper developing simulated annealing.^[ref]

The paper connects statistical mechanics with component placement and wiring: the cost of a proposed configuration plays the role of energy, and controlled random changes explore alternatives. His later work also included optical switching and wavelength-division multiplexing in broadband networks, illustrating a career spanning physical devices and communication systems.^[ref]

Hermann Anton Haus was an electrical engineer whose research ranged from quantum optics to optical communication systems and ultrashort laser pulses. His work on optical solitons helped connect nonlinear wave propagation with the transmission of information through optical fibers.^[ref]

With James R. Melcher, he wrote Electromagnetic Fields and Energy by Hermann A. Haus and James R. Melcher, a text that links field equations with concrete devices and demonstrations. Its magnetic circuit analysis, for example, shows how geometry and constitutive assumptions turn an electromagnetic field problem into an approximate engineering model.^[ref]

James R. Melcher was an electrical engineer whose work helped define continuum electromechanics: the interaction of electromagnetic fields with deformable materials and flowing fluids. His applications included energy conversion, flow measurement and the control of industrial processes.^[ref]

With Hermann Anton Haus, he wrote Electromagnetic Fields and Energy by Hermann A. Haus and James R. Melcher. A central engineering theme is the relation between a full field description and a justified approximation. In a magnetic circuit, for example, geometry and permeability assumptions determine when a small set of circuit-like variables can represent the spatial fields.^[ref]

John Bertrand Johnson was an electrical engineer whose 1928 measurements established the thermal electrical fluctuations now called Johnson-Nyquist noise. He detected random voltage fluctuations in conductors through a vacuum-tube amplifier and a thermocouple, and related the measured effect to temperature, electrical resistance and the measurement system's frequency response.^[ref]

This reveals why the average voltage alone is not enough to characterize a fluctuating signal. Its expected value can vanish while its mean-square value is positive. The fluctuations become an experimentally measurable noise floor in sensitive electronics, and their temperature dependence connects circuit measurements with the Boltzmann constant.^[ref]

Harry Nyquist was an electrical engineer whose work connected communication engineering with physical and mathematical limits. His 1928 theory explained thermal electrical fluctuations using thermodynamics and statistical mechanics, agreeing with John Bertrand Johnson's measurements.^[ref]

In the classical regime $hf\ll k_{B}T$, an approximately constant electrical resistance $R$ at temperature $T$ produces an open-circuit voltage expected value square $⟨V^2⟩=4k_{B}TR\Delta f$ over a one-sided frequency band of width $\Delta f$. Here $k_B$ is the Boltzmann constant. The formula connects Johnson-Nyquist noise with both the physical conductor and the signal bandwidth through which it is observed.^[ref]

An electrical engineer who co-invented the electron microscope with Ernst Ruska.^[ref]