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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 magne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetron2
The cavity magnetron is a high-power vacuum tube used in early radar systems and subsequently in microwave oven, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patrol Aircraft
A maritime patrol aircraft (MPA), also known as a patrol aircraft, maritime reconnaissance aircraft, maritime surveillance 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). In addition to dedicated airframes, mid-size and large business jets have been modified for MPA missions, offering rapid deployment, extended range, long endurance, and lower life-cycle costs. 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 wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Night-fighter
A night fighter (later known as all-weather fighter or all-weather interceptor post-Second World War) is a largely historical term for a fighter or interceptor aircraft adapted or designed for effective use at night, during periods of adverse meteorological conditions, or in otherwise poor visibility. Such designs were in direct contrast to day fighters: fighters and interceptors designed primarily for use during the day or during good weather. The concept of the night fighter was developed and experimented with during the First World War but would not see widespread use until WWII. The term would be supplanted by “all-weather fighter/interceptor” post-WWII, with advancements in various technologies permitting the use of such aircraft in virtually all conditions. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilowatt
The watt (symbol: W) is the unit of Power (physics), power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantification (science), quantify the rate of Work (physics), energy transfer. The watt is named in honor of James Watt (1736–1819), an 18th-century Scottish people, Scottish inventor, mechanical engineer, and chemist who improved the Newcomen engine with his own Watt steam engine, steam engine in 1776, which became fundamental for the Industrial Revolution. Overview When an object's velocity is held constant at one meter per second against a constant opposing force of one Newton (unit), newton, the rate at which Work (physics), work is done is one watt. \mathrm. In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V), meaning the watt is equivalent to the vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Birmingham
The University of Birmingham (informally Birmingham University) is a Public university, public research university in Birmingham, England. It received its royal charter in 1900 as a successor to Queen's College, Birmingham (founded in 1825 as the William Sands Cox, Birmingham School of Medicine and Surgery), and Mason Science College (established in 1875 by Sir Josiah Mason), making it the first English red brick university, civic or 'red brick' university to receive its own royal charter, and the first English Collegiate university, unitary university. It is a founding member of both the Russell Group of British research universities and the international network of research universities, Universitas 21. The student population includes undergraduate and postgraduate students (), which is the List of universities in the United Kingdom by enrollment, largest in the UK (out of ). The annual income of the university for 2023–24 was £926 million of which £205.2 mil ... [...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 awar ... [...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 Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telefunken
Telefunken was a German radio and television producer, founded in Berlin in 1903 as a joint venture between Siemens & Halske and the ''AEG (German company), Allgemeine Elektrizitäts-Gesellschaft'' (AEG) ("General electricity company"). Prior to World War I, the company set up the first world-wide network of communications and was the first in the world to sell electronic televisions with cathode-ray tubes, in Germany in 1934. The brand had several incarnations: * ''Gesellschaft für drahtlose Telegraphie Gesellschaft mit beschränkter Haftung, m.b.H., System Telefunken'', founded in 1903 as a joint venture between AEG and Siemens & Halske * ''Telefunken, Gesellschaft für drahtlose Telegraphie m.b.H.'', in 1923; since 1941 as subsidiary of AEG alone * ''Telefunken Gesellschaft mit beschränkter Haftung, GmbH'', in 1955 * ''Telefunken Aktiengesellschaft (AG)'', in 1963 * ''Allgemeine Elektrizitäts-Gesellschaft AEG-Telefunken'', created in 1967 through a merger between Telefunken ... [...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 Arms industry, defence electronics, communications, and engineering. It was originally founded in 1886 as G. Binswanger and Company as an electrical goods wholesaler based in London. It quickly adopted a then-unorthodox business model of supplying electrical components over the counter. In 1889, the business was incorporated as the General Electric Company Ltd, and became a public limited company 11 years later. During the 1890s and 1900s, the company heavily invested into electric lighting, a sector that proved to be immensely profitable in the long term. The GEC was heavily impacted by the outbreak of the First World War, supplying various goods to the military, and thus becoming a major player in the electrical industry. In 1921, a new purpose-built company headquarters (Magnet House) was opened in Kingsway, London; two years later, GEC's industrial research laboratories at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philips
Koninklijke Philips N.V. (), simply branded Philips, is a Dutch multinational health technology company that was founded in Eindhoven in 1891. Since 1997, its world headquarters have been situated in Amsterdam, though the Benelux headquarters is still in Eindhoven. The company gained its royal honorary title in 1998. Philips was founded by Gerard Philips and his father Frederik, with their first products being light bulbs. Through the 20th century, it grew into one of the world's largest electronics conglomerates, with global market dominance in products ranging from kitchen appliances and electric shavers to light bulbs, televisions, cassettes, and compact discs (both of which were invented by Philips). At one point, it played a dominant role in the entertainment industry (through PolyGram). However, intense competition from primarily East Asian competitors throughout the 1990s and 2000s led to a period of downsizing, including the divestment of its lighting and c ... [...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 Technische Hochschule in Darmstadt (now Technische Universität 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
