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Cavity Magnetron
The cavity magnetron is a high-power vacuum tube used in early radar systems and subsequently in microwave ovens and in linear particle accelerators. A cavity magnetron generates microwaves using the interaction of a stream of electrons with a magnetic field, while moving past a series of cavity resonators, which are small, open cavities in a metal block. Electrons pass by the cavities and cause microwaves to oscillate within, similar to the functioning of a whistle producing a tone when excited by an air stream blown past its opening. The resonant frequency of the arrangement is determined by the cavities' physical dimensions. Unlike other vacuum tubes, such as a klystron or a traveling-wave tube (TWT), the magnetron cannot function as an amplifier for increasing the intensity of an applied microwave signal; the magnetron serves solely as an electronic oscillator generating a microwave signal from direct current electricity supplied to the vacuum tube. The use of magnetic fie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetron2
The cavity magnetron is a high-power vacuum tube used in early radar systems and currently in microwave ovens and linear particle accelerators. It generates microwaves using the interaction of a stream of electrons with a magnetic field while moving past a series of cavity resonators, which are small, open cavities in a metal block. Electrons pass by the cavities and cause microwaves to oscillate within, similar to the functioning of a whistle producing a tone when excited by an air stream blown past its opening. The resonant frequency of the arrangement is determined by the cavities' physical dimensions. Unlike other vacuum tubes, such as a klystron or a traveling-wave tube (TWT), the magnetron cannot function as an amplifier for increasing the intensity of an applied microwave signal; the magnetron serves solely as an oscillator, generating a microwave signal from direct current electricity supplied to the vacuum tube. The use of magnetic fields as a means to control the flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lee De Forest
Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor and a fundamentally important early pioneer in electronics. He invented the first electronic device for controlling current flow; the three-element "Audion" triode vacuum tube in 1906. This started the Electronic Age, and enabled the development of the electronic amplifier and oscillator. These made radio broadcasting and long distance telephone lines possible, and led to the development of talking motion pictures, among countless other applications. He had over 300 patents worldwide, but also a tumultuous career— he boasted that he made, then lost, four fortunes. He was also involved in several major patent lawsuits, spent a substantial part of his income on legal bills, and was even tried (and acquitted) for mail fraud. Despite this, he was recognised for his pioneering work with the 1922 IEEE Medal of Honor, the 1923 Franklin Institute Elliott Cresson Medal and the 1946 American Institute of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allies Of World War II
The Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during the Second World War (1939–1945) to oppose the Axis powers, led by Nazi Germany, Imperial Japan, and Fascist Italy. Its principal members by 1941 were the United Kingdom, United States, Soviet Union, and China. Membership in the Allies varied during the course of the war. When the conflict broke out on 1 September 1939, the Allied coalition consisted of the United Kingdom, France, and Poland, as well as their respective dependencies, such as British India. They were soon joined by the independent dominions of the British Commonwealth: Canada, Australia, New Zealand and South Africa. Consequently, the initial alliance resembled that of the First World War. As Axis forces began invading northern Europe and the Balkans, the Allies added the Netherlands, Belgium, Norway, Greece, and Yugoslavia. The Soviet Union, which initially had a nonaggression pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patrol Aircraft
A maritime patrol aircraft (MPA), also known as a patrol aircraft, maritime reconnaissance aircraft, or by the older American term patrol bomber, is a fixed-wing aircraft designed to operate for long durations over water in maritime patrol roles — in particular anti-submarine warfare (ASW), anti-ship warfare (AShW), and search and rescue (SAR). Among other maritime surveillance resources, such as satellites, ships, unmanned aerial vehicles (UAVs) and helicopters, the MPA is an important asset. To perform ASW operations, MPAs typically carry air-deployable sonar buoys as well as torpedoes and are usually capable of extended flight at low altitudes. History First World War The first aircraft that would now be identified as maritime patrol aircraft were flown by the Royal Naval Air Service and the French Aéronautique Maritime during the First World War, primarily on anti-submarine patrols. France, Italy and Austria-Hungary used large numbers of smaller patrol aircraft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Night-fighter
A night fighter (also known as all-weather fighter or all-weather interceptor for a period of time after the Second World War) is a fighter aircraft adapted for use at night or in other times of bad visibility. Night fighters began to be used in World War I and included types that were specifically modified to operate at night. During the Second World War, night fighters were either purpose-built night fighter designs, or more commonly, heavy fighters or light bombers adapted for the mission, often employing radar or other systems for providing some sort of detection capability in low visibility. Many night fighters of the conflict also included instrument landing systems for landing at night, as turning on the runway lights made runways into an easy target for opposing intruders. Some experiments tested the use of day fighters on night missions, but these tended to work only under very favourable circumstances and were not widely successful. Avionics systems were greatly mini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Birmingham
, mottoeng = Through efforts to heights , established = 1825 – Birmingham School of Medicine and Surgery1836 – Birmingham Royal School of Medicine and Surgery1843 – Queen's College1875 – Mason Science College1898 – Mason University College1900 – gained university status by royal charter , city = Birmingham , province = West Midlands , country = England, UK , coor = , campus = Urban, suburban , academic_staff = 5,495 (2020) , administrative_staff = , head_label = Visitor , head = The Rt Hon Penny Mordaunt MP , chancellor = Lord Bilimoria , vice_chancellor = Adam Tickell , type = Public , endowment = £134.5 million (2021) , budget = £774.1 million (2020–21) , students = () , undergrad = () , postgrad = () , affiliations = Universitas 21Universities UK EUA ACUSutton 13Russell Group , free_label = , free = , colours = The University , website = , logo = The University of Birmingham (informally Birmingham University) i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harry Boot
Henry Albert Howard Boot (29 July 1917 – 8 February 1983) was an English physicist who with Sir John Randall and James Sayers developed the cavity magnetron, which was one of the keys to the Allied victory in the Second World War. Biography Henry Boot was born in Birmingham and attended King Edward's School, Birmingham and the University of Birmingham. While working on his PhD the war broke out. His professor Mark Oliphant had seen the klystron at Stanford University but it produced insufficient power to be useful as a radar transmitter. He assigned John Randall and Boot to the problem. By late February 1940, they had invented the much more powerful cavity magnetron which was fitted in an experimental radar by May 1940. James Sayers later refined the magnetron still further by strapping alternate cavities. As with many British inventions of this period, the magnetron was provided to the US for free when they entered World War II. Initially Boot and Randall were awarded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Randall (physicist)
Sir John Turton Randall, (23 March 1905 – 16 June 1984) was an English physicist and biophysicist, credited with radical improvement of the cavity magnetron, an essential component of centimetric wavelength radar, which was one of the keys to the Allied victory in the Second World War. It is also the key component of microwave ovens. Randall collaborated with Harry Boot, and they produced a valve that could spit out pulses of microwave radio energy on a wavelength of 10 cm. On the significance of their invention, Professor of military history at the University of Victoria in British Columbia, David Zimmerman, states: "The magnetron remains the essential radio tube for shortwave radio signals of all types. It not only changed the course of the war by allowing us to develop airborne radar systems, it remains the key piece of technology that lies at the heart of your microwave oven today. The cavity magnetron's invention changed the world." Randall also led the King's Col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telefunken
Telefunken was a German radio and television apparatus company, founded in Berlin in 1903, as a joint venture of Siemens & Halske and the ''Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ('General electricity company'). The name "Telefunken" appears in: * the product brand name "Telefunken"; * ''Gesellschaft für drahtlose Telegraphie m.b.H., System Telefunken'', founded 1903 in Berlin as a subsidiary of AEG and Siemens & Halske; * ''Telefunken, Gesellschaft für drahtlose Telegraphie m.b.H.'' (from 1923 to 1955 – since 1941 subsidiary of the AEG only); * ''Telefunken GmbH'' in 1955; * ''Telefunken Aktiengesellschaft (AG)'' in 1963; * Merger of AEG and Telefunken to form ''Allgemeine Elektrizitäts-Gesellschaft AEG-Telefunken'' (from 1967 to 1979); * AEG-TELEFUNKEN AG (from 1979 to 1985); * ''TELEFUNKEN Fernseh und Rundfunk GmbH'', Hanover (1972, subsidiary of AEG-TELEFUNKEN); * Telefunken electronic GmbH (a spin-off of AEG-Telefunken and DASA * the company (since 1992 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Electric Company
The General Electric Company (GEC) was a major British industrial conglomerate involved in consumer and defence electronics, communications, and engineering. The company was founded in 1886, was Britain's largest private employer with over 250,000 employees in the 1980s, and at its peak in the 1990s, made profits of over £1 billion a year. In June 1998, GEC sold its share of the joint venture GEC-Alsthom on the Paris stock exchange. In December 1999, GEC's defence arm, Marconi Electronic Systems, was sold to British Aerospace, forming BAE Systems. The rest of GEC, mainly telecommunications equipment manufacturing, continued as Marconi Communications. After buying several US telecoms manufacturers at the top of the market, losses following the bursting of the dot-com bubble in 2001 led to the restructuring in 2003 of Marconi plc into Marconi Corporation plc. In 2005, Ericsson acquired the bulk of that company. What was left of the business was renamed Telent. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philips
Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters is still in Eindhoven. Philips was formerly one of the largest electronics companies in the world, but is currently focused on the area of health technology, having divested its other divisions. The company was founded in 1891 by Gerard Philips and his father Frederik, with their first products being light bulbs. It currently employs around 80,000 people across 100 countries. The company gained its royal honorary title (hence the ''Koninklijke'') in 1998 and dropped the "Electronics" in its name in 2013, due to its refocusing from consumer electronics to healthcare technology. Philips is organized into three main divisions: Personal Health (formerly Philips Consumer Electronics and Philips Domestic Appliances and Personal Care), Connecte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Hollmann
Hans Erich (Eric) Hollmann (4 November 1899 – 19 November 1960) was a German electronic specialist who made several breakthroughs in the development of radar. Hollmann was born in Solingen, Germany. He became interested in radio and even as a teenager subscribed to the technical magazines of the day. Late in World War I he became a prisoner of war of the French and did not return to Germany until 1920. He then studied at the Technical University at Darmstadt until he received his doctorate in 1928. Hollmann's doctoral research included the development of an ultra-short-wave transmitter and receiver for centimetre and decimetre waves. This gained the attention of ''Telefunken'', and ultimately led to their development of the first microwave telecommunication system. In 1930 Hollmann moved to the Heinrich-Hertz Institute for Oscillatory Research in Berlin. There he continued studies in microwaves and cathode ray tubes and also worked on the ionosphere research and radio astr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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