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|Harold Alden Wheeler|
|Born||May 10, 1903|
|Died||April 25, 1996 92)(aged|
|Awards||IEEE Medal of Honor (1964)|
Harold Alden Wheeler (May 10, 1903 - April 25, 1996) was a noted American electrical engineer.
The United States of America (USA), commonly known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, and various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is slightly smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U.S. is the third most populous country. The capital is Washington, D.C., and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico. The State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean. The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The extremely diverse geography, climate, and wildlife of the United States make it one of the world's 17 megadiverse countries.
Wheeler was born in Saint Paul, Minnesota, to William Archibald Wheeler and Harriet Marie Alden Wheeler (a descendant of John and Priscilla Alden), graduated in 1925 from George Washington University with a Bachelor of Science degree in physics and was awarded the Ruggles Prize for excellence in Mathematics. Subsequently he studied physics at Johns Hopkins University until 1928. During his education he worked part-time at the National Bureau of Standards' Radio Laboratory, then from 1922 onwards with Prof. Louis Alan Hazeltine at Stevens Institute of Technology after discovering that they had independently invented the Neutrodyne receiver. (It entered large-scale production in 1923, and was the dominant receiver for most of the 1920s.)
Saint Paul is the capital and second-most populous city of the U.S. state of Minnesota. As of 2017, the city's estimated population was 309,180. Saint Paul is the county seat of Ramsey County, the smallest and most densely populated county in Minnesota. The city lies mostly on the east bank of the Mississippi River in the area surrounding its point of confluence with the Minnesota River, and adjoins Minneapolis, the state's largest city. Known as the "Twin Cities", the two form the core of Minneapolis–Saint Paul, the 16th-largest metropolitan area in the United States, with about 3.6 million residents.
The George Washington University is a private research university in Washington, D.C. It was chartered in 1821 by an act of the United States Congress.
A Bachelor of Science is an undergraduate academic degree awarded for completed courses that generally last three to five years, or a person holding such a degree.
In 1924 he became Hazeltine Corporation's first employee, and in 1925 created the first radio receiver with a diode automatic volume control that maintained a constant sound level while tuning to broadcasts of differing strengths. AM radio receivers incorporating this circuit came into use about 1930, and it has been included in every set since. He led the Hazeltine laboratory 1930-1939, and during this time received patents for 126 inventions on a wide range of work including circuits, test equipment, acoustics, antennas, transmission lines, methods of calculation for inductance of coils (included in all relevant textbooks since the mid-1930s), skin effect, coupled circuit theory, television scanning theory, and analysis and design of wide-band TV amplifiers.
Hazeltine Corporation was a defense electronics company which is now part of BAE Systems Inc.
Acoustics is the branch of physics that deals with the study of all mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician while someone working in the field of acoustics technology may be called an acoustical engineer. The application of acoustics is present in almost all aspects of modern society with the most obvious being the audio and noise control industries.
In radio engineering, an antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver. In transmission, a radio transmitter supplies an electric current to the antenna's terminals, and the antenna radiates the energy from the current as electromagnetic waves. In reception, an antenna intercepts some of the power of a radio wave in order to produce an electric current at its terminals, that is applied to a receiver to be amplified. Antennas are essential components of all radio equipment.
In World War II Wheeler led work on Identification friend or foe (IFF) antennas for aircraft, surface vessels, submarines, and ground stations. By war's end, these "lifesaver antennas" had been placed on all Allied ships. In 1946 he founded Wheeler Laboratories, Inc., to develop microwave circuits and antennas for missile systems tracking and guidance radar. In 1959, when it became a Hazeltine subsidiary, he was named a Hazeltine director and vice-president.
World War II, also known as the Second World War, was a global war that lasted from 1939 to 1945. The vast majority of the world's countries—including all the great powers—eventually formed two opposing military alliances: the Allies and the Axis. A state of total war emerged, directly involving more than 100 million people from over 30 countries. The major participants threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. World War II was the deadliest conflict in human history, marked by 50 to 85 million fatalities, most of whom were civilians in the Soviet Union and China. It included massacres, the genocide of the Holocaust, strategic bombing, premeditated death from starvation and disease, and the only use of nuclear weapons in war.
Identification, friend or foe (IFF) is a radar-based identification system designed for command and control. It uses a transponder that listens for an interogation signal and then sends a response consisting of a unique signal that identifies the broadcaster. It enables military and civilian air traffic control interrogation systems to identify aircraft, vehicles or forces as friendly and to determine their bearing and range from the interrogator. IFF may be used by both military and civilian aircraft. IFF was first developed during the Second World War, with the arrival of radar, and several infamous friendly fire incidents.
Microwaves are a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter; with frequencies between 300 MHz (1 m) and 300 GHz (1 mm). Different sources define different frequency ranges as microwaves; the above broad definition includes both UHF and EHF bands. A more common definition in radio engineering is the range between 1 and 100 GHz. In all cases, microwaves include the entire SHF band at minimum. Frequencies in the microwave range are often referred to by their IEEE radar band designations: S, C, X, Ku, K, or Ka band, or by similar NATO or EU designations.
All told, Wheeler held 180 United States patents and received over fifty awards. He was a member of the National Academy of Engineering, a Fellow of the Institute of Radio Engineers (1927) and of the American Institute of Electrical Engineers (1946), and awarded the IEEE Morris N. Liebmann Memorial Award in 1940 "for his contribution to the analysis of wide-band high-frequency circuits particularly suitable for television", and the IEEE Medal of Honor in 1964 "for his analyses of the fundamental limitations on the resolution in television systems and on wideband amplifiers, and for his basic contributions to the theory and development of antennas, microwave elements, circuits, and receivers." He was also a member of Sigma Xi, Tau Beta Pi, and the Defense Science Board.
The National Academy of Engineering (NAE) is an American nonprofit, non-governmental organization. The National Academy of Engineering is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Sciences (NAS), the National Academy of Medicine, and the National Research Council.
The Institute of Radio Engineers (IRE) was a professional organization which existed from 1912 until December 31, 1962. On January 1, 1963 it merged with the American Institute of Electrical Engineers (AIEE) to form the Institute of Electrical and Electronics Engineers (IEEE).
The American Institute of Electrical Engineers (AIEE) was a United States-based organization of electrical engineers that existed from 1884 through 1962. On January 1, 1963 it merged with the Institute of Radio Engineers (IRE) to form the Institute of Electrical and Electronics Engineers (IEEE).
Electronics comprises the physics, engineering, technology and applications that deal with the emission, flow and control of electrons in vacuum and matter. The identification of the electron in 1897, along with the invention of the vacuum tube, which could amplify and rectify small electrical signals, inaugurated the field of electronics and the electron age.
Harold Stephen Black was an American electrical engineer, who revolutionized the field of applied electronics by discovering the negative feedback amplifier in 1927. To some, his discovery is considered the most important breakthrough of the twentieth century in the field of electronics, since it has a wide area of application. This is because all electronic devices are inherently nonlinear, but they can be made substantially linear with the application of negative feedback. Negative feedback works by sacrificing gain for higher linearity. By sacrificing gain, it also has an additional effect of increasing the bandwidth of the amplifier. However, a negative feedback amplifier can be unstable such that it may oscillate. Once the stability problem is solved, the negative feedback amplifier is extremely useful in the field of electronics. Black published a famous paper, Stabilized feedback amplifiers, in 1934.
The Audion was an electronic detecting or amplifying vacuum tube invented by American electrical engineer Lee de Forest in 1906. It was the first triode, consisting of an evacuated glass tube containing three electrodes: a heated filament, a grid, and a plate. It is important in the history of technology because it was the first widely used electronic device which could amplify; a small electrical signal applied to the grid could control a larger current flowing from the filament to plate.
A regenerative circuit is an amplifier circuit that employs positive feedback. Some of the output of the amplifying device is applied back to its input so as to add to the input signal, increasing the amplification. One example is the Schmitt trigger, but the most common use of the term is in RF amplifiers, and especially regenerative receivers, to greatly increase the gain of a single amplifier stage.
This is an alphabetical list of articles pertaining specifically to electrical and electronics engineering. For a thematic list, please see List of electrical engineering topics. For a broad overview of engineering, see List of engineering topics. For biographies, see List of engineers.
The Neutrodyne radio receiver, invented in 1922 by Louis Hazeltine, was a particular type of tuned radio frequency (TRF) receiver, in which the instability-causing inter-electrode capacitance of the triode RF tubes is cancelled out or "neutralized". to prevent parasitic oscillations which caused "squealing" or "howling" noises in the speakers of early radio sets. In most designs, a small extra winding on each of the RF amplifiers' tuned anode coils was used to generate a small antiphase signal, which could be adjusted by special variable trim capacitors to cancel out the stray signal coupled to the grid via plate-to-grid capacitance. The Neutrodyne circuit was popular in radio receivers until the 1930s, when it was superseded by the superheterodyne receiver.
Albert Wallace Hull is an American physicist and electrical engineer who made contributions to the development of vacuum tubes, and invented the magnetron. He was a member of the National Academy of Sciences.
George Harold Brown was an American research engineer. He was a prolific inventor who held more than 80 patents and wrote over 100 technical papers.
Dr. David B. Rutledge is the Kiyo and Eiko Tomiyasu Professor (em.) of Engineering and former Chair of the Division of Engineering and Applied Science at the California Institute of Technology (Caltech). His earlier work on microwave circuits has been important for various advances in wireless communications and has been useful for applications such as radar, remote sensing, and satellite broadcasting. He also covers research in estimating fossil-fuel supplies, and the implications for alternative energy sources and climate change.
Harald Trap Friis, who published as H. T. Friis, was a Danish-American radio engineer whose work at Bell Laboratories included pioneering contributions to radio propagation, radio astronomy, and radar. His two Friis formulas remain widely used.
Radio-frequency engineering, or RF engineering, is a subset of electrical and electronic engineering involving the application of transmission line, waveguide, antenna and electromagnetic field principles to the design and application of devices that produce or utilize signals within the radio band, the frequency range of about 20 kHz up to 300 GHz.
Dr. Frederick Britton Llewellyn was a noted American electrical engineer.
Arthur V. Loughren was an American electrical engineer who played a prominent role in the development of NTSC television.
Ronold Wyeth Percival King was an American applied physicist, known for his contributions to the theory and application of microwave antennas. He published twelve books and over three hundred articles in his area, as well as mentored one hundred doctoral dissertations.
Antti V. Räisänen, D.Sc. (Tech.), is a Finnish scientist. He is the Professor and Head of the Department of Radio Science and Engineering in Aalto University. He is also the Director of SMARAD.
Electronic engineering is an electrical engineering discipline which utilizes nonlinear and active electrical components to design electronic circuits, devices, VLSI devices and their systems. The discipline typically also designs passive electrical components, usually based on printed circuit boards.
Andrea Alù is the founding director of the Photonics Initiative at the CUNY Advanced Science Research Center, Einstein Professor of Physics at the CUNY Graduate Center, and Professor of Electrical Engineering at The City College of New York. Previously he was the Temple Foundation Endowed professor at the University of Texas at Austin. Alù is a significant contributor to the field of novel or advanced materials research. He has authored over 200 journal papers, 15 book chapters, 270 conference papers, and is attributed with over 29,000 citations, which includes some published research that has been cited by over 100 and over 200 others. Professionally, he is currently a member of the Institute of Electrical and Electronics Engineers, IEEE Antennas and Propagation Society (2003), IEEE Microwave Theory and Techniques Society (2003), IEEE Communications Society, the American Association for the Advancement of Science (2007), and a senior fellow of the Optical Society of America (2007).
Christophe Caloz is a researcher and professor of electrical engineering and physics at École Polytechnique de Montréal. He graduated from the Swiss Federal Institute of Technology in Lausanne, Switzerland, where he received a Diploma of electrical engineering in telecommunications in 1995 and a Ph.D in electromagnetics in 2000. From 2001 to 2004, he was a Postdoctoral Research Engineer at the Microwave Electronics Laboratory of University of California at Los Angeles, before joining the École Polytechnique de Montréal as the Canada Research Chair in radio-frequency metamaterials.
Octavio M. "Tav" Salati was an American engineer, academic and educator. He served as Professor of Electrical Engineering at the University of Pennsylvania in the field of Electromagnetic Compatibility.