920:, where it was shown on 19 September 1940 in Alfred Loomis’ apartment. The American NDRC Microwave Committee was stunned at the power level produced. However Bell Labs' director was upset when it was X-rayed and had eight holes rather than the six holes shown on the GEC plans. After contacting (via the transatlantic cable) Dr Eric Megaw, GEC’s vacuum tube expert Megaw recalled that when he had asked for 12 prototypes he said make 10 with 6 holes, one with 7 and one with 8; there was no time to amend the drawings. And No 12 with 8 holes was chosen for the Tizard Mission. So Bell Labs chose to copy the sample; and while early British magnetrons had six cavities the American ones had eight cavities.
885:
55:
419:
205:, England in 1940. Their first working example produced hundreds of watts at 10 cm wavelength, an unprecedented achievement. Within weeks, engineers at GEC had improved this to well over a kilowatt, and within months 25 kilowatts, over 100 kW by 1941 and pushing towards a megawatt by 1943. The high power pulses were generated from a device the size of a small book and transmitted from an antenna only centimeters long, reducing the size of practical radar systems by orders of magnitude. New radars appeared for
459:
them. The anode is constructed of a highly conductive material, almost always copper, so these differences in voltage cause currents to appear to even them out. Since the current has to flow around the outside of the cavity, this process takes time. During that time additional electrons will avoid the hot spots and be deposited further along the anode, as the additional current flowing around it arrives too. This causes an oscillating current to form as the current tries to equalize one spot, then another.
622:
165:, USA, began development of magnetrons to avoid de Forest's patents, but these were never completely successful. Other experimenters picked up on Hull's work and a key advance, the use of two cathodes, was introduced by Habann in Germany in 1924. Further research was limited until Okabe's 1929 Japanese paper noting the production of centimeter-wavelength signals, which led to worldwide interest. The development of magnetrons with multiple cathodes was proposed by A. L. Samuel of
488:
297:, resulting in considerable research into alternate tube designs that would avoid his patents. One concept used a magnetic field instead of an electrical charge to control current flow, leading to the development of the magnetron tube. In this design, the tube was made with two electrodes, typically with the cathode in the form of a metal rod in the center, and the anode as a cylinder around it. The tube was placed between the poles of a
63:
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1126:. Exceptions to this are higher power magnetrons that operate above approximately 10,000 volts where positive ion bombardment becomes damaging to thorium metal, hence pure tungsten (potassium doped) is used. While thorium is a radioactive metal, the risk of cancer is low as it never gets airborne in normal usage. Only if the filament is taken out of the magnetron, finely crushed, and inhaled can it pose a health hazard.
523:. Spaced around the rim of the chamber are cylindrical cavities. Slots are cut along the length of the cavities that open into the central, common cavity space. As electrons sweep past these slots, they induce a high-frequency radio field in each resonant cavity, which in turn causes the electrons to bunch into groups. A portion of the radio frequency energy is extracted by a short coupling loop that is connected to a
333:, these electrons radiate radio frequency energy. The effect is not very efficient. Eventually the electrons hit one of the electrodes, so the number in the circulating state at any given time is a small percentage of the overall current. It was also noticed that the frequency of the radiation depends on the size of the tube, and even early examples were built that produced signals in the microwave regime.
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shift within an individual transmitted pulse. The second factor is that the energy of the transmitted pulse is spread over a relatively wide frequency spectrum, which requires the receiver to have a correspondingly wide bandwidth. This wide bandwidth allows ambient electrical noise to be accepted into the receiver, thus obscuring somewhat the weak radar echoes, thereby reducing overall receiver
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771:. He settled on a system consisting of a diode with a cylindrical anode surrounding a rod-shaped cathode, placed in the middle of a magnet. The attempt to measure the electron mass failed because he was unable to achieve a good vacuum in the tube. However, as part of this work, Greinacher developed mathematical models of the motion of the electrons in the crossed magnetic and electric fields.
806:, investigated the magnetron for his doctoral dissertation of 1924. Throughout the 1920s, Hull and other researchers around the world worked to develop the magnetron. Most of these early magnetrons were glass vacuum tubes with multiple anodes. However, the two-pole magnetron, also known as a split-anode magnetron, had relatively low efficiency.
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of the device was greatly improved. Unfortunately, the higher field also meant that electrons often circled back to the cathode, depositing their energy on it and causing it to heat up. As this normally causes more electrons to be released, it could sometimes lead to a runaway effect, damaging the device.
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The magnetron is a self-oscillating device requiring no external elements other than a power supply. A well-defined threshold anode voltage must be applied before oscillation will build up; this voltage is a function of the dimensions of the resonant cavity, and the applied magnetic field. In pulsed
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Since all of the electrons in the flow experienced this looping motion, the amount of RF energy being radiated was greatly improved. And as the motion occurred at any field level beyond the critical value, it was no longer necessary to carefully tune the fields and voltages, and the overall stability
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systems became widely available in the late 1930s, the ultra high frequency and microwave bands were well beyond the ability of conventional circuits. The magnetron was one of the few devices able to generate signals in the microwave band and it was the only one that was able to produce high power at
1029:
Centimetric radar, made possible by the cavity magnetron, allowed for the detection of much smaller objects and the use of much smaller antennas. The combination of small-cavity magnetrons, small antennas, and high resolution allowed small, high quality radars to be installed in aircraft. They could
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Several characteristics of the magnetron's output make radar use of the device somewhat problematic. The first of these factors is the magnetron's inherent instability in its transmitter frequency. This instability results not only in frequency shifts from one pulse to the next, but also a frequency
462:
The oscillating currents flowing around the cavities, and their effect on the electron flow within the tube, cause large amounts of microwave radiofrequency energy to be generated in the cavities. The cavities are open on one end, so the entire mechanism forms a single, larger, microwave oscillator.
372:
The original magnetron was very difficult to keep operating at the critical value, and even then the number of electrons in the circling state at any time was fairly low. This meant that it produced very low-power signals. Nevertheless, as one of the few devices known to create microwaves, interest
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Hull's magnetron was not originally intended to generate VHF (very-high-frequency) electromagnetic waves. However, in 1924, Czech physicist August Žáček (1886–1961) and German physicist Erich Habann (1892–1968) independently discovered that the magnetron could generate waves of 100 megahertz to 1
671:
mounted on a recreational vessel, a radar with a magnetron output of 2 to 4 kilowatts is often found mounted very near an area occupied by crew or passengers. In practical use these factors have been overcome, or merely accepted, and there are today thousands of magnetron aviation and marine radar
316:
At very high magnetic field settings the electrons are forced back onto the cathode, preventing current flow. At the opposite extreme, with no field, the electrons are free to flow straight from the cathode to the anode. There is a point between the two extremes, the critical value or Hull cut-off
458:
The magnetic field is set to a value well below the critical, so the electrons follow curved paths towards the anode. When they strike the anode, they cause it to become negatively charged in that region. As this process is random, some areas will become more or less charged than the areas around
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At any given instant, the electron will naturally be pushed towards the lower-voltage side of the tube. The electron will then oscillate back and forth as the voltage changes. At the same time, a strong magnetic field is applied, stronger than the critical value in the original design. This would
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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
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Mechanically, the cavity magnetron consists of a large, solid cylinder of metal with a hole drilled through the centre of the circular face. A wire acting as the cathode is run down the center of this hole, and the metal block itself forms the anode. Around this hole, known as the "interaction
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produced a working prototype of a cavity magnetron that produced about 400 W. Within a week this had improved to 1 kW, and within the next few months, with the addition of water cooling and many detail changes, this had improved to 10 and then 25 kW. To deal with its drifting
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The modern magnetron is a fairly efficient device. In a microwave oven, for instance, a 1.1-kilowatt input will generally create about 700 watts of microwave power, an efficiency of around 65%. (The high-voltage and the properties of the cathode determine the power of a magnetron.) Large
704:, the waveguide leads to a radio-frequency-transparent port into the cooking chamber. As the fixed dimensions of the chamber and its physical closeness to the magnetron would normally create standing wave patterns in the chamber, the pattern is randomized by a motorized fan-like
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proposed in 1937 a system with "six or eight small holes" drilled in a metal block, differing from the later production designs only in the aspects of vacuum sealing. However, his idea was rejected by the Navy, who said their valve department was far too busy to consider it.
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magnetrons can produce up to 2.5 megawatts peak power with an average power of 3.75 kW. Some large magnetrons are water cooled. The magnetron remains in widespread use in roles which require high power, but where precise control over frequency and phase is unimportant.
1921:
Günter Nagel, "Pionier der
Funktechnik. Das Lebenswerk des Wissenschaftlers Erich Habann, der in Hessenwinkel lebte, ist heute fast vergessen" (Pioneer in Radio Technology. The life's work of scientist Erich Habann, who lived in Hessenwinkel, is nearly forgotten today.),
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and other effects, results in a slower and less faithful response to control current than electrostatic control using a control grid in a conventional triode (not to mention greater weight and complexity), so magnetrons saw limited use in conventional electronic designs.
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Where there are an even number of cavities, two concentric rings can connect alternate cavity walls to prevent inefficient modes of oscillation. This is called pi-strapping because the two straps lock the phase difference between adjacent cavities at π radians (180°).
659:. The magnetron is operated with very short pulses of applied voltage, resulting in a short pulse of high-power microwave energy being radiated. As in all primary radar systems, the radiation reflected from a target is analyzed to produce a radar map on a screen.
384:. As the name implies, this design used an anode that was split in two—one at each end of the tube—creating two half-cylinders. When both were charged to the same voltage the system worked like the original model. But by slightly altering the voltage of the two
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With no magnetic field present, the tube operates as a diode, with electrons flowing directly from the cathode to the anode. In the presence of the magnetic field, the electrons will experience a force at right angles to their direction of motion (the
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be used by maritime patrol aircraft to detect objects as small as a submarine periscope, which allowed aircraft to attack and destroy submerged submarines which had previously been undetectable from the air. Centimetric contour mapping radars like
262:. The components are normally arranged concentrically, placed within a tubular-shaped container from which all air has been evacuated, so that the electrons can move freely (hence the name "vacuum" tubes, called "valves" in British English).
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and others, limited to perhaps 10 W output. By this time the klystron was producing more power and the magnetron was not widely used, although a 300W device was built by
Aleksereff and Malearoff in the USSR in 1936 (published in 1940).
786:'s patents on the control of current flow using electric fields via the "grid". Hull intended to use a variable magnetic field, instead of an electrostatic one, to control the flow of the electrons from the cathode to the anode. Working at
126:, 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
825:, around 10 cm (3 GHz), rather than the 50 to 150 cm (200 MHz) that was available from tube-based generators of the time. It was known that a multi-cavity resonant magnetron had been developed and patented in 1935 by
2140:
Slutzkin, A. A.; Steinberg, D. S. (May 1929). "Die
Erzeugung von kurzwelligen ungedämpften Schwingungen bei Anwendung des Magnetfeldes" [The generation of undamped shortwave oscillations by application of a magnetic field].
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in the waveguide (more often in commercial ovens), or by a turntable that rotates the food (most common in consumer ovens). An early example of this application was when
British scientists in 1954 used a microwave oven to resurrect
388:, the electrons' trajectory could be modified so that they would naturally travel towards the lower voltage side. The plates were connected to an oscillator that reversed the relative voltage of the two plates at a given frequency.
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in
September 1940. As the discussion turned to radar, the US Navy representatives began to detail the problems with their short-wavelength systems, complaining that their klystrons could only produce 10 W. With a flourish,
49:
Magnetron with section removed to exhibit the cavities. The cathode in the center is not visible. The antenna emitting microwaves is at the left. The magnets producing a field parallel to the long axis of the device are not
470:
As the oscillation takes some time to set up, and is inherently random at the start, subsequent startups will have different output parameters. Phase is almost never preserved, which makes the magnetron difficult to use in
927:, Randall and Boot's discovery was "a massive, massive breakthrough" and "deemed by many, even now , to be the most important invention that came out of the Second World War", while professor of military history at the
519:. The electrons initially move radially outward from the cathode attracted by the electric field of the anode walls. The magnetic field causes the electrons to spiral outward in a circular path, a consequence of the
534:
The size of the cavities determine the resonant frequency, and thereby the frequency of the emitted microwaves. However, the frequency is not precisely controllable. The operating frequency varies with changes in load
269:) is inserted between the cathode and the anode, the flow of electrons between the cathode and anode can be regulated by varying the voltage on this third electrode. This allows the resulting electron tube (called a "
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device to specifically detect it. Centimetric gun-laying radars were likewise far more accurate than the older technology. They made the big-gunned Allied battleships more deadly and, along with the newly developed
233:" from the radar display. The magnetron remains in use in some radar systems, but has become much more common as a low-cost source for microwave ovens. In this form, over one billion magnetrons are in use today.
431:
space", are a number of similar holes ("resonators") drilled parallel to the interaction space, connected to the interaction space by a short channel. The resulting block looks something like the cylinder on a
676:, which have a narrower output frequency range. These allow a narrower receiver bandwidth to be used, and the higher signal-to-noise ratio in turn allows a lower transmitter power, reducing exposure to EMR.
224:
emerged. A key characteristic of the magnetron is that its output signal changes from pulse to pulse, both in frequency and phase. This renders it less suitable for pulse-to-pulse comparisons for performing
909:
coupling ("strapping") alternate cavities within the magnetron, which reduced the instability by a factor of 5–6. (For an overview of early magnetron designs, including that of Boot and
Randall, see .)
696:, cooled by airflow from a fan. The magnetic field is produced by two powerful ring magnets, the lower of which is just visible. Almost all modern oven magnetrons are of similar layout and appearance.
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A "tap", normally a wire formed into a loop, extracts microwave energy from one of the cavities. In some systems the tap wire is replaced by an open hole, which allows the microwaves to flow into a
625:
9.375 GHz 20 kW (peak) magnetron assembly for an early commercial airport radar in 1947. In addition to the magnetron (right), it contains a TR (transmit/receive) switch tube and the
491:
Cutaway drawing of a cavity magnetron of 1984. Part of the righthand magnet and copper anode block is cut away to show the cathode and cavities. This older magnetron uses two horseshoe shaped
277:
because small variations in the electric charge applied to the control grid will result in identical variations in the much larger current of electrons flowing between the cathode and anode.
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applications there is a delay of several cycles before the oscillator achieves full peak power, and the build-up of anode voltage must be coordinated with the build-up of oscillator output.
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frequency, they sampled the output signal and synchronized their receiver to whatever frequency was actually being generated. In 1941, the problem of frequency instability was solved by
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and thus performance. The third factor, depending on application, is the radiation hazard caused by the use of high-power electromagnetic radiation. In some applications, for example, a
794:, Hull built tubes that provided switching through the control of the ratio of the magnetic and electric field strengths. He released several papers and patents on the concept in 1921.
317:
magnetic field (and cut-off voltage), where the electrons just reach the anode. At fields around this point, the device operates similar to a triode. However, magnetic control, due to
392:
normally cause the electron to circle back to the cathode, but due to the oscillating electrical field, the electron instead follows a looping path that continues toward the anodes.
329:
spectrum. This occurs because a few of the electrons, instead of reaching the anode, continue to circle in the space between the cathode and the anode. Due to an effect now known as
1238:
527:(a metal tube, usually of rectangular cross section). The waveguide directs the extracted RF energy to the load, which may be a cooking chamber in a microwave oven or a high-gain
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to develop various types of radar using the magnetron. By early 1941, portable centimetric airborne radars were being tested in
American and British aircraft. In late 1941, the
2054:
Kaiser, W. (1994). "The
Development of Electron Tubes and of Radar technology: The Relationship of Science and Technology". In Blumtritt, O.; Petzold, H.; Aspray, W. (eds.).
217:
held a lead in radar that their counterparts in
Germany and Japan were never able to close. By the end of the war, practically every Allied radar was based on the magnetron.
309:). In this case, the electrons follow a curved path between the cathode and anode. The curvature of the path can be controlled by varying either the magnetic field using an
1050:, made anti-aircraft guns much more dangerous to attacking aircraft. The two coupled together and used by anti-aircraft batteries, placed along the flight path of German
415:, which works on entirely different principles. In this design the oscillation is created by the physical shape of the anode, rather than external circuits or fields.
1997:Žáček, A. (1928). "Über eine Methode zur Erzeugung von sehr kurzen elektromagnetischen Wellen" [On a method for generating very short electromagnetic waves].
1900:
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has no cooling blood flow, it is particularly prone to overheating when exposed to microwave radiation. This heating can in turn lead to a higher incidence of
1986:
2009:Žáček, A., "Spojení pro výrobu elektrických vln" , Czechoslovak patent no. 20,293 (filed: 31 May 1924; issued: 15 February 1926). Available (in Czech) at:
3837:
743:, etc.). Although efficient, these lamps are much more complex than other methods of lighting and therefore not commonly used. More modern variants use
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systems. Frequency also drifts from pulse to pulse, a more difficult problem for a wider array of radar systems. Neither of these present a problem for
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at a high (continuous or pulsed) negative potential created by a high-voltage, direct-current power supply. The cathode is placed in the center of an
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instead. But klystrons could not at that time achieve the high power output that magnetrons eventually reached. This was one reason that German
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A similar magnetron with a different section removed. Central cathode is visible; antenna conducting microwaves at the top; magnets are not shown.
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where the receiver can be synchronized with an imprecise magnetron frequency. Where precise frequencies are needed, other devices, such as the
539:, with changes in the supply current, and with the temperature of the tube. This is not a problem in uses such as heating, or in some forms of
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802:, published first; however, he published in a journal with a small circulation and thus attracted little attention. Habann, a student at the
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833:. However, the German military considered the frequency drift of Hollman's device to be undesirable, and based their radar systems on the
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units in service. Recent advances in aviation weather-avoidance radar and in marine radar have successfully replaced the magnetron with
1065:. The use in radar itself has dwindled to some extent, as more accurate signals have generally been needed and developers have moved to
66:
Obsolete 9 GHz magnetron tube and magnets from a Soviet aircraft radar. The tube is embraced between the poles of two horseshoe-shaped
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International
Conference on the Origins and Evolution of the Cavity Magnetron (CAVMAG 2010), Bournemouth, England, UK, 19–20 April 2010
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Since then, many millions of cavity magnetrons have been manufactured; while some have been for radar the vast majority have been for
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The magnetron continued to be used in radar in the post-war period but fell from favour in the 1960s as high-power klystrons and
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Brookner, Eli (19–20 April 2010). "From $ 10,000 magee to $ 7 magee and $ 10 transmitter and receiver (T/R) on single chip".
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in microwave radar equipment and is often credited with giving Allied radar a considerable performance advantage over
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in the United Kingdom used the magnetron to develop a revolutionary airborne, ground-mapping radar codenamed H2S. The
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to generate the microwaves, which are substantially less complex and can be adjusted to maximize light output using a
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The use of magnetic fields as a means to control the flow of an electric current was spurred by the invention of the
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1983:
74:, which create a magnetic field along the axis of the tube. The microwaves are emitted from the waveguide aperture
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The electromagnet used in conjunction with Randall and Boot's original magnetron, in the Science Museum, London.
842:
2785:
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Lipman, R. M.; B. J. Tripathi; R. C. Tripathi (1988). "Cataracts induced by microwave and ionizing radiation".
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There is also a considerable electrical hazard around magnetrons, as they require a high voltage power supply.
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at Wembley made 12 prototype cavity magnetrons in August 1940, and No 12 was sent to America with Bowen on the
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1930:, a daily newspaper of the city of Frankfurt in the state of Brandenburg, Germany), 15 December 2006, page 9.
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should offer the magnetron to the Americans in exchange for their financial and industrial help. An early 10
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of the arrangement is determined by the cavities' physical dimensions. Unlike other vacuum tubes, such as a
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Concise, notably-excellent article about magnetrons; Fig. 13 is representative of a modern radar magnetron.
2463:
1195:
Redhead, Paul A., "The Invention of the Cavity Magnetron and its Introduction into Canada and the U.S.A.",
957:
924:
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In 1910 Hans Gerdien (1877–1951) of the Siemens Corporation invented a magnetron. In 1912, Swiss physicist
524:
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Lythall, B. W. (1995). "Basic science and research for naval radar, 1935-1945". In Kingsley, F. A. (ed.).
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which in use is attached to a waveguide conducting the microwaves to the radar antenna. Modern tubes use
1578:"Resuscitation of Hamsters after Supercooling or Partial Crystallization at Body Temperatures Below 0°C"
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It was noticed that when the magnetron was operating at the critical value, it would emit energy in the
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radars, thus directly influencing the outcome of the war. It was later described by American historian
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for front-line aircraft, were not a match for their British counterparts. Likewise, in the UK,
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for increasing the intensity of an applied microwave signal; the magnetron serves solely as an
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mixer. The waveguide aperture (left) would be connected to a waveguide going to the antenna.
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generating a microwave signal from direct current electricity supplied to the vacuum tube.
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Willshaw, W. E.; L. Rushforth; A. G. Stainsby; R. Latham; A. W. Balls; A. H. King (1946).
1211:
Blind Bombing: How Microwave Radar brought the Allies to D-Day and Victory in World War II
1058:, are credited with destroying many of the flying bombs before they reached their target.
511:, lobed, circular metal chamber. The walls of the chamber are the anode of the tube. A
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arranged such that the magnetic field was aligned parallel to the axis of the electrodes.
8:
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2401:(Baxter was the official historian of the Office of Scientific Research and Development.)
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Please expand the section to include this information. Further details may exist on the
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magnetron. Magnetic lines of force are parallel to the geometric axis of this structure.
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782:'s patents on the triode. Western Electric had gained control of this design by buying
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made of solid copper, with the resonant frequency defined entirely by its dimensions.
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Radar Origins Worldwide: History of Its Evolution in 13 Nations Through World War II
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Brittain, James E. (1985). "The magnetron and the beginnings of the microwave age".
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U.S. patent no. 2,123,728 (filed: 1936 November 27 ; issued: 1938 July 12).
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2010 International Conference on the Origins and Evolution of the Cavity Magnetron
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took the example and quickly began making copies, and before the end of 1940, the
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Habann, Erich (1924). "Eine neue Generatorröhre" [A new generator tube].
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3199:
3167:
2660: Hans Erich Hollmann/Telefunken GmbH: „Magnetron“ filed November 27, 1935
2624:
2312:
Journal of the Institution of Electrical Engineers - Part IIIA: Radiolocation
2162:
1678:
Goerth, Joachim (2010). "Early magnetron development especially in Germany".
1609:
1485:
J. Brittain (1985). "The Magnetron and the Beginnings of the Microwave Age".
1093:
1000:
838:
826:
783:
768:
520:
310:
306:
294:
206:
170:
154:
2204:
Okabe, Kinjiro (1929). "On the short-wave limit of magnetron oscillations".
487:
3695:
3683:
3571:
3538:
3367:
3352:
2919:
2383:
The magnetron stunned the Americans. Their research was years off the pace.
2305:
1655:] (in German). Berlin, Germany: Springer Verlag. p. 514 footnote.
1617:
1011:
949:
814:
740:
706:
668:
472:
266:
2440:
2277:"M.J.B.Scanlan; Early Centimetric Ground Radars – A Personal Reminiscence"
1775:
443:, not the core, of the conductor, the parallel sides of the slot act as a
3737:
3479:
3428:
3334:
3319:
3102:
3064:
1942:] (in German). New York: Waxmann Publishing Co. p. 251 footnote.
1123:
775:
728:
440:
247:
158:
95:
2777:
1213:. Nebraska: Potomac Books/University of Nebraska Press. pp. 24–26.
353:
3809:
3799:
3732:
3606:
3576:
3543:
3518:
3513:
3490:
3362:
3342:
3220:
3082:
3059:
2945:
2847:
2842:
2837:
1936:
Für und Wider "Hitlers Bombe": Studien zur Atomforschung in Deutschland
1883:
1092:
At least one hazard in particular is well known and documented. As the
901:
861:
822:
712:
673:
452:
318:
198:
182:
2432:
1940:
For and Against "Hitler's Bomb": Studies on atomic research in Germany
1601:
944:
and Britain had no money to develop the magnetron on a massive scale,
735:
to the lighting cavity containing the light-emitting substance (e.g.,
3772:
3616:
3611:
3601:
3528:
3408:
3242:
3237:
3162:
3087:
2090:
1853:
1828:
1506:
1097:
1031:
996:
818:
732:
693:
464:
444:
423:
406:
274:
251:
139:
111:
1577:
731:, a magnetron provides the microwave field that is passed through a
62:
3794:
3742:
3722:
3700:
3586:
3581:
3469:
3458:
3387:
3157:
2217:
Okabe, Kinjiro (1930). "On the magnetron oscillation of new type".
1149:
1140:
1119:
1101:
1085:
1066:
953:
834:
716:
544:
448:
435:, with a somewhat larger central hole. Early models were cut using
432:
254:
are emitted from a negatively charged, heated component called the
131:
115:
32:
28:
2410:
2181:
Yagi, Hidetsugu (1928). "Beam transmission of ultra-short waves".
977:
pulled out a magnetron and explained it produced 1000 times that.
876:
853:
313:, or by changing the electrical potential between the electrodes.
3654:
3591:
3413:
3398:
3252:
3209:
2857:
1115:
1015:
961:
504:
255:
174:
1081:
577:
3727:
3418:
3382:
3347:
2907:
2879:
2852:
2827:
2262:
The Development of Radar Equipments for the Royal Navy, 1935–45
1862:(Anon.) (1956). "The 70th birthday of Prof. Dr. August Žáček".
1055:
965:
830:
736:
560:
508:
492:
270:
258:
and are attracted to a positively charged component called the
213:
and even the smallest escort ships, and from that point on the
150:
67:
1641:
Gerdien, H., Deutsches Reichspatent 276,528 (12 January 1910).
692:
with magnet in its mounting box. The horizontal plates form a
3804:
3715:
3474:
3247:
3040:
2902:
2897:
1154:
1019:
810:
684:
652:
540:
439:
pistol jigs. Remembering that in an AC circuit the electrons
259:
99:
45:
2399:. Boston, Massachusetts: Little, Brown, and Co. p. 142.
3747:
3130:
3076:
2977:
2930:
2868:
2773:
Valve oscillator circuits; radio frequency output couplings
2197:
Journal of the Institute of Electrical Engineering of Japan
941:
744:
1962:[New method of generating undamped oscillations].
1576:
Smith, A. U.; Lovelock, J. E.; Parkes, A. S. (June 1954).
1789:
Journal of the American Institute of Electrical Engineers
373:
in the device and potential improvements was widespread.
273:" because it now has three electrodes) to function as an
2454:
Australian Nuclear Science and Technology Organisation.
1697:[On an apparatus for the determination of e/m].
1026:
as "he most valuable cargo ever brought to our shores".
2264:. London, England: Macmillan Press Ltd. pp. 68–69.
1699:
Verhandlungen der Deutschen Physikalischen Gesellschaft
2127:
Slutskin, Abram A.; Shteinberg, Dmitry S. (1927). "".
2114:
Slutskin, Abram A.; Shteinberg, Dmitry S. (1926). "".
864:'s original cavity magnetron developed in 1940 at the
503:
All cavity magnetrons consist of a heated cylindrical
2559:
2342:
1648:
Taschenbuch der drahtlosen Telegraphie und Telephonie
285:
The idea of using a grid for control was invented by
2191:
Magnetrons are discussed in Part II of this article.
1253:
1034:
improved the accuracy of Allied bombers used in the
336:
Early conventional tube systems were limited to the
169:
in 1934, leading to designs by Postumus in 1934 and
27:"Magnetron" redirects here. Not to be confused with
1575:
1419:"Electric Valves: Diodes, Triodes, and Transistors"
515:parallel to the axis of the cavity is imposed by a
2126:
2113:
655:set, the magnetron's waveguide is connected to an
193:magnetron was a radical improvement introduced by
2139:
727:In microwave-excited lighting systems, such as a
280:
3829:
2607:Magnetron collection in the Virtual Valve Museum
2514:
1934:Karlsch, Rainer; Petermann, Heiko, eds. (2007).
1933:
1653:Pocket book of wireless telegraphy and telephony
365:Installed for use between the poles of a strong
2621:Videos of plasmoids created in a microwave oven
2363:"How the search for a 'death ray' led to radar"
2219:Proceedings of the Institute of Radio Engineers
2206:Proceedings of the Institute of Radio Engineers
2183:Proceedings of the Institute of Radio Engineers
1918:Biographical information about Erich Habann:
1682:. Piscataway, New Jersey: IEEE. pp. 17–22.
1960:"Nová metoda k vytvorení netlumenych oscilací"
1823:Biographical information about August Žáček:
1556:Electronics Engineer's Reference Book, 4th ed.
931:in British Columbia, David Zimmerman, states:
817:, there arose an urgent need for a high-power
404:The great advance in magnetron design was the
293:in 1905. In the USA it was later patented by
2793:
2693:High frequency resonator and circuit therefor
778:put this work to use in an attempt to bypass
236:
2545:: CS1 maint: multiple names: authors list (
2116:Журнал Русского Физико-Химического Общества
1695:"Über eine Anordnung zur Bestimmung von e/m"
1010:The cavity magnetron was widely used during
1550:
1548:
1546:
1484:
1320:"How important was Tizard's Box of Tricks?"
1284:
1280:
1278:
1276:
1274:
1272:
1270:
1268:
798:gigahertz. Žáček, a professor at Prague's
241:
138:(TWT), the magnetron cannot function as an
3838:Science and technology during World War II
2800:
2786:
2560:Jr. Raymond C. Watson (25 November 2009).
1692:
1356:
1354:
1110:Most magnetrons contain a small amount of
767:was looking for new ways to calculate the
2807:
2049:
2047:
1975:
1964:Časopis Pro Pěstování Matematiky a Fysiky
1852:
1191:
1189:
993:Telecommunications Research Establishment
2757:Inductance-capacitance resonance circuit
2233:
2068:
2058:. Piscataway, NJ: IEEE. pp. 217–36.
1644:
1543:
1478:
1360:
1317:
1313:
1311:
1265:
1080:
883:
875:
852:
683:
620:
486:
417:
352:
348:
61:
53:
44:
2404:
2360:
2259:
1861:
1351:
1202:
841:radars, which never strayed beyond the
14:
3830:
2566:. Trafford Publishing. pp. 315–.
2394:
2053:
2044:
2031:
1677:
1531:from the original on 11 September 2017
1450:
1448:
1446:
1444:
1297:from the original on November 15, 2007
1186:
1038:, despite the existence of the German
940:Because France had just fallen to the
2781:
2496:from the original on 5 September 2017
2216:
2203:
2194:
1996:
1957:
1826:
1728:from the original on 23 December 2017
1404:." University of London Ph.D. Thesis.
1308:
1237:. Bournemouth University. 1995–2009.
989:Massachusetts Institute of Technology
987:had been set up on the campus of the
114:using the interaction of a stream of
3232:Three-dimensional integrated circuit
2395:Baxter, James Phinney (III) (1946).
2348:
2180:
1782:
1749:
1287:"Briefcase 'that changed the world'"
1259:
1208:
1088:Warning sign: Non-ionizing radiation
647:History of radar (Centimetric radar)
571:
376:The first major improvement was the
173:in 1935. Production was taken up by
163:General Electric Research Laboratory
3013:Programmable unijunction transistor
2527:from the original on 1 October 2006
2515:EPA,OAR,ORIA,RPD, US (2014-07-16).
2486:"EngineerGuy Video: microwave oven"
2373:from the original on 9 October 2017
2274:
2034:Zeitschrift für Hochfrequenztechnik
1999:Zeitschrift für Hochfrequenztechnik
1441:
1429:from the original on 25 August 2017
1406:December 2004. Accessed 2009-08-23.
923:According to Andy Manning from the
674:microwave semiconductor oscillators
399:
24:
2914:Multi-gate field-effect transistor
1783:Hull, Albert W. (September 1921).
1716:Wolff, Dipl.-Ing. (FH) Christian.
1395:3D Computer Modeling of Magnetrons
482:
25:
3879:
3868:World War II American electronics
2892:Insulated-gate bipolar transistor
2590:
2287:from the original on 4 March 2016
2195:Okabe, Kinjiro (March 1928). "".
1984:Czech Digital Mathematics Library
1715:
1466:from the original on 3 March 2016
1416:
1241:from the original on 26 July 2011
1076:
956:version, built in England by the
821:generator that worked at shorter
361:The bare tube, about 11 cm high.
357:Split-anode magnetron (c. 1935).
246:In a conventional electron tube (
3863:World War II British electronics
3136:Heterostructure barrier varactor
2863:Chemical field-effect transistor
2011:Czech Industrial Property Office
1558:Newnes-Butterworth, London 1976
1285:Angela Hind (February 5, 2007).
576:
122:, while moving past a series of
42:Device for generating microwaves
3184:Mixed-signal integrated circuit
2634:Information and PDF Data Sheets
2553:
2508:
2478:
2447:
2388:
2361:Harford, Tim (9 October 2017).
2354:
2299:
2268:
2253:
2097:
2062:
2025:
1948:
1912:
1864:Czechoslovak Journal of Physics
1817:
1740:
1709:
1686:
1671:
1632:
1569:
1513:
1340:from the original on 2011-06-17
567:
422:A cross-sectional diagram of a
265:If a third electrode (called a
110:. A cavity magnetron generates
1410:
1387:
1227:
447:while the round holes form an
281:Hull or single-anode magnetron
13:
1:
2056:Tracking the History of Radar
1525:hyperphysics.phy-astr.gsu.edu
1180:
382:negative-resistance magnetron
3215:Silicon controlled rectifier
3077:Organic light-emitting diode
2967:Diffused junction transistor
2425:10.1016/0039-6257(88)90088-4
2129:Український фізичний журнал
1460:electriciantraining.tpub.com
1318:Schroter, B. (Spring 2008).
936:invention changed the world.
925:RAF Air Defence Radar Museum
790:'s Research Laboratories in
413:electron-resonance magnetron
108:linear particle accelerators
102:systems and subsequently in
7:
3019:Static induction transistor
2956:Bipolar junction transistor
2908:MOS field-effect transistor
2880:Fin field-effect transistor
2723: Spencer, P.L. (1946).
2638:(Title is somewhat cryptic)
1801:10.1109/JoAIEE.1921.6594005
1371:10.1109/CAVMAG.2010.5565574
1129:
981:Bell Telephone Laboratories
813:was being developed during
749:power semiconductor devices
722:
629:receiver front end, a 2K25
479:, nor for microwave ovens.
167:Bell Telephone Laboratories
86:which are much less bulky.
10:
3884:
3226:Static induction thyristor
2771: Dexter, S.A. (1959).
2739: Carter, P.S. (1948).
2707: Carter, P.S. (1944).
2691: Carter, P.S. (1944).
2673: Buchholz, H. (1943).
1645:Banneitz, F., ed. (1927).
1036:strategic bombing campaign
843:low-UHF band to start with
758:
679:
644:
495:magnets, modern tubes use
237:Construction and operation
26:
3763:
3663:
3630:
3562:
3499:
3427:
3395:(Hexode, Heptode, Octode)
3333:
3265:
3147:Hybrid integrated circuit
3111:
3039:
2990:Light-emitting transistor
2944:
2826:
2815:
2324:10.1049/ji-3a-1.1946.0188
1982:Available (in Czech) at:
1977:10.21136/CPMF.1924.121857
1073:systems for these needs.
999:was in part developed by
960:Research Laboratories in
37:Magneton (disambiguation)
3442:Backward-wave oscillator
3152:Light emitting capacitor
3008:Point-contact transistor
2978:Junction Gate FET (JFET)
2741:Cavity resonator circuit
2709:Cavity resonator circuit
2163:10.1002/andp.19293930504
1750:Hull, Albert W. (1921).
1024:James Phinney Baxter III
958:General Electric Company
894:University of Birmingham
866:University of Birmingham
616:
441:travel along the surface
345:centimeter wavelengths.
242:Conventional tube design
227:moving target indication
203:University of Birmingham
179:General Electric Company
3453:Crossed-field amplifier
2972:Field-effect transistor
2755: Rex, H.B. (1952).
2413:Survey of Ophthalmology
2397:Scientists Against Time
1896:Available on-line at:
1693:Greinacher, H. (1912).
1136:Crossed-field amplifier
291:Nobel Prize for Physics
211:anti-submarine aircraft
3622:Voltage-regulator tube
3189:MOS integrated circuit
3054:Constant-current diode
3030:Unijunction transistor
2517:"Radiation Protection"
2239:Hollmann, Hans Erich,
1958:Žáček, A. (May 1924).
1089:
938:
929:University of Victoria
889:
881:
873:
870:Science Museum, London
868:, England, now in the
697:
642:
587:is missing information
531:in the case of radar.
500:
477:continuous-wave radars
427:
369:
215:Allies of World War II
87:
59:
51:
3691:Electrolytic detector
3464:Inductive output tube
3280:Low-dropout regulator
3195:Organic semiconductor
3126:Printed circuit board
2962:Darlington transistor
2809:Electronic components
2456:"In the home – ANSTO"
2199:(in Japanese): 284ff.
1928:Märkische Oderzeitung
1827:Fürth, R. H. (1962).
1776:10.1103/PhysRev.18.31
1521:"Magnetron Operation"
1209:Fine, Norman (2019).
1197:La Physique au Canada
1084:
933:
887:
879:
856:
792:Schenectady, New York
687:
665:signal-to-noise ratio
624:
490:
421:
378:split-anode magnetron
356:
349:Split-anode magnetron
144:electronic oscillator
65:
57:
48:
3848:Microwave technology
3509:Beam deflection tube
3178:Metal-oxide varistor
3071:Light-emitting diode
2925:Thin-film transistor
2886:Floating-gate MOSFET
2281:www.radarpages.co.uk
1924:Bradenburger Blätter
1829:"Prof. August Žáček"
1722:www.radartutorial.eu
1165:Radiation Laboratory
985:Radiation Laboratory
847:Albert Beaumont Wood
591:Magnetron sputtering
340:bands, and although
222:traveling-wave tubes
82:, electromagnets or
3485:Traveling-wave tube
3285:Switching regulator
3121:Printed electronics
3098:Step recovery diode
2875:Depletion-load NMOS
2490:www.engineerguy.com
2466:on 5 September 2017
2173:Japanese engineers:
2155:1929AnP...393..658S
2083:1985PhT....38g..60B
1926:(supplement of the
1876:1956CzJPh...6..204.
1845:1962Natur.193..625F
1768:1921PhRv...18...31H
1594:1954Natur.173.1136S
1499:1985PhT....38g..60B
1170:Traveling-wave tube
1160:Microwave EMP Rifle
1071:traveling-wave tube
968:, was taken on the
765:Heinrich Greinacher
342:very high frequency
331:cyclotron radiation
289:, who received the
136:traveling-wave tube
3843:English inventions
3790:Crystal oscillator
3650:Variable capacitor
3325:Switched capacitor
3267:Voltage regulators
3141:Integrated circuit
3025:Tetrode transistor
3003:Pentode transistor
2996:Organic LET (OLET)
2983:Organic FET (OFET)
2630:2023-06-19 at the
2612:2011-07-16 at the
2246:2018-01-14 at the
2143:Annalen der Physik
2106:Soviet physicists:
2103:See for example:
2016:2011-07-18 at the
1989:2011-07-18 at the
1903:2012-03-12 at the
1884:10.1007/BF01699894
1566:, pp. 7-71 to 7-77
1400:2008-10-10 at the
1090:
890:
882:
874:
804:University of Jena
800:Charles University
698:
643:
501:
497:rare-earth magnets
428:
380:, also known as a
370:
128:resonant frequency
88:
80:rare-earth magnets
60:
52:
3825:
3824:
3785:Ceramic resonator
3597:Mercury-arc valve
3549:Video camera tube
3501:Cathode-ray tubes
3261:
3260:
2869:Complementary MOS
2573:978-1-4269-2110-0
2367:BBC World Service
2351:, pp. 56–64.
2040:: 115–20, 135–41.
1602:10.1038/1731136a0
1588:(4415): 1136–37.
1554:L.W. Turner,(ed),
1380:978-1-4244-5609-3
1327:Imperial Engineer
1262:, pp. 24–26.
1145:as early as 1939.
946:Winston Churchill
688:Magnetron from a
614:
613:
124:cavity resonators
16:(Redirected from
3875:
3679:electrical power
3564:Gas-filled tubes
3448:Cavity magnetron
3275:Linear regulator
2824:
2823:
2802:
2795:
2788:
2779:
2778:
2770:
2769:
2765:
2754:
2753:
2749:
2738:
2737:
2733:
2725:Magnetron casing
2722:
2721:
2717:
2706:
2705:
2701:
2690:
2689:
2685:
2676:Cavity resonator
2672:
2671:
2667:
2659:
2658:
2654:
2619:MicrowaveCam.com
2585:
2584:
2582:
2580:
2557:
2551:
2550:
2544:
2536:
2534:
2532:
2512:
2506:
2505:
2503:
2501:
2482:
2476:
2475:
2473:
2471:
2462:. Archived from
2460:www.ansto.gov.au
2451:
2445:
2444:
2408:
2402:
2400:
2392:
2386:
2385:
2380:
2378:
2358:
2352:
2346:
2340:
2339:
2337:
2335:
2326:. Archived from
2303:
2297:
2296:
2294:
2292:
2272:
2266:
2265:
2257:
2251:
2237:
2231:
2226:
2213:
2200:
2190:
2166:
2136:
2131:(in Ukrainian).
2123:
2101:
2095:
2094:
2091:10.1063/1.880982
2066:
2060:
2059:
2051:
2042:
2041:
2029:
2023:
2006:
1981:
1979:
1952:
1946:
1943:
1916:
1910:
1895:
1858:
1856:
1854:10.1038/193625b0
1821:
1815:
1812:
1779:
1744:
1738:
1737:
1735:
1733:
1713:
1707:
1706:
1690:
1684:
1683:
1675:
1669:
1666:
1636:
1630:
1629:
1573:
1567:
1552:
1541:
1540:
1538:
1536:
1517:
1511:
1510:
1507:10.1063/1.880982
1482:
1476:
1475:
1473:
1471:
1452:
1439:
1438:
1436:
1434:
1414:
1408:
1391:
1385:
1384:
1365:. pp. 1–2.
1358:
1349:
1348:
1346:
1345:
1339:
1324:
1315:
1306:
1305:
1303:
1302:
1282:
1263:
1257:
1251:
1250:
1248:
1246:
1231:
1225:
1224:
1220:978-1640-12279-6
1206:
1200:
1193:
1054:on their way to
1052:V-1 flying bombs
950:Sir Henry Tizard
892:In 1940, at the
858:Sir John Randall
788:General Electric
780:Western Electric
635:local oscillator
609:
606:
600:
580:
572:
517:permanent magnet
400:Cavity magnetron
367:permanent magnet
299:horseshoe magnet
94:is a high-power
92:cavity magnetron
21:
3883:
3882:
3878:
3877:
3876:
3874:
3873:
3872:
3828:
3827:
3826:
3821:
3759:
3674:audio and video
3659:
3626:
3558:
3495:
3423:
3404:Photomultiplier
3329:
3257:
3205:Quantum circuit
3113:
3107:
3049:Avalanche diode
3035:
2947:
2940:
2829:
2818:
2811:
2806:
2767:
2761:
2751:
2745:
2735:
2729:
2719:
2713:
2703:
2697:
2687:
2681:
2669:
2663:
2656:
2650:
2632:Wayback Machine
2614:Wayback Machine
2593:
2588:
2578:
2576:
2574:
2558:
2554:
2538:
2537:
2530:
2528:
2513:
2509:
2499:
2497:
2484:
2483:
2479:
2469:
2467:
2452:
2448:
2409:
2405:
2393:
2389:
2376:
2374:
2359:
2355:
2347:
2343:
2333:
2331:
2318:(5): 985–1005.
2304:
2300:
2290:
2288:
2275:Barrett, Dick.
2273:
2269:
2258:
2254:
2248:Wayback Machine
2238:
2234:
2102:
2098:
2067:
2063:
2052:
2045:
2030:
2026:
2018:Wayback Machine
1991:Wayback Machine
1953:
1949:
1917:
1913:
1905:Wayback Machine
1822:
1818:
1785:"The magnetron"
1756:Physical Review
1745:
1741:
1731:
1729:
1714:
1710:
1691:
1687:
1676:
1672:
1663:
1637:
1633:
1574:
1570:
1553:
1544:
1534:
1532:
1519:
1518:
1514:
1483:
1479:
1469:
1467:
1456:"The Magnetron"
1454:
1453:
1442:
1432:
1430:
1415:
1411:
1402:Wayback Machine
1392:
1388:
1381:
1359:
1352:
1343:
1341:
1337:
1322:
1316:
1309:
1300:
1298:
1283:
1266:
1258:
1254:
1244:
1242:
1235:"The Magnetron"
1233:
1232:
1228:
1221:
1207:
1203:
1199:, November 2001
1194:
1187:
1183:
1132:
1112:beryllium oxide
1104:in later life.
1079:
1063:microwave ovens
761:
725:
702:microwave ovens
682:
649:
639:germanium diode
631:reflex klystron
627:superheterodyne
619:
610:
604:
601:
594:
581:
570:
485:
483:Common features
424:resonant cavity
407:resonant cavity
402:
351:
327:radio frequency
283:
244:
239:
104:microwave ovens
84:ferrite magnets
43:
40:
23:
22:
15:
12:
11:
5:
3881:
3871:
3870:
3865:
3860:
3855:
3850:
3845:
3840:
3823:
3822:
3820:
3819:
3818:
3817:
3812:
3802:
3797:
3792:
3787:
3782:
3781:
3780:
3769:
3767:
3761:
3760:
3758:
3757:
3756:
3755:
3753:Wollaston wire
3745:
3740:
3735:
3730:
3725:
3720:
3719:
3718:
3713:
3703:
3698:
3693:
3688:
3687:
3686:
3681:
3676:
3667:
3665:
3661:
3660:
3658:
3657:
3652:
3647:
3646:
3645:
3634:
3632:
3628:
3627:
3625:
3624:
3619:
3614:
3609:
3604:
3599:
3594:
3589:
3584:
3579:
3574:
3568:
3566:
3560:
3559:
3557:
3556:
3551:
3546:
3541:
3536:
3534:Selectron tube
3531:
3526:
3524:Magic eye tube
3521:
3516:
3511:
3505:
3503:
3497:
3496:
3494:
3493:
3488:
3482:
3477:
3472:
3467:
3461:
3456:
3450:
3445:
3438:
3436:
3425:
3424:
3422:
3421:
3416:
3411:
3406:
3401:
3396:
3390:
3385:
3380:
3375:
3370:
3365:
3360:
3355:
3350:
3345:
3339:
3337:
3331:
3330:
3328:
3327:
3322:
3317:
3312:
3307:
3302:
3297:
3292:
3287:
3282:
3277:
3271:
3269:
3263:
3262:
3259:
3258:
3256:
3255:
3250:
3245:
3240:
3235:
3229:
3223:
3218:
3212:
3207:
3202:
3197:
3192:
3186:
3181:
3175:
3170:
3165:
3160:
3155:
3149:
3144:
3138:
3133:
3128:
3123:
3117:
3115:
3109:
3108:
3106:
3105:
3100:
3095:
3093:Schottky diode
3090:
3085:
3080:
3074:
3068:
3062:
3057:
3051:
3045:
3043:
3037:
3036:
3034:
3033:
3027:
3022:
3016:
3010:
3005:
3000:
2999:
2998:
2987:
2986:
2985:
2980:
2969:
2964:
2959:
2952:
2950:
2942:
2941:
2939:
2938:
2933:
2928:
2922:
2917:
2911:
2905:
2900:
2895:
2889:
2883:
2877:
2872:
2866:
2860:
2855:
2850:
2845:
2840:
2834:
2832:
2821:
2813:
2812:
2805:
2804:
2797:
2790:
2782:
2776:
2775:
2759:
2743:
2727:
2711:
2695:
2679:
2661:
2647:
2646:
2642:
2641:
2635:
2625:TMD Magnetrons
2622:
2616:
2604:
2598:
2597:
2592:
2591:External links
2589:
2587:
2586:
2572:
2552:
2507:
2477:
2446:
2403:
2387:
2353:
2341:
2330:on May 5, 2018
2298:
2267:
2252:
2232:
2230:
2229:
2228:
2227:
2225:(10): 1748–49.
2214:
2201:
2192:
2175:
2174:
2170:
2169:
2168:
2167:
2137:
2124:
2118:(in Russian).
2108:
2107:
2096:
2061:
2043:
2024:
2022:
2021:
2007:
1994:
1947:
1945:
1944:
1931:
1911:
1909:
1908:
1859:
1816:
1814:
1813:
1780:
1739:
1718:"Radar Basics"
1708:
1685:
1670:
1668:
1667:
1661:
1642:
1631:
1568:
1542:
1512:
1477:
1440:
1417:White, Steve.
1409:
1386:
1379:
1350:
1307:
1264:
1252:
1226:
1219:
1201:
1184:
1182:
1179:
1178:
1177:
1175:Tizard Mission
1172:
1167:
1162:
1157:
1152:
1147:
1138:
1131:
1128:
1078:
1077:Health hazards
1075:
1048:proximity fuze
1005:Bernard Lovell
970:Tizard Mission
918:Tizard Mission
760:
757:
753:PID controller
747:or GaN-on-SiC
724:
721:
690:microwave oven
681:
678:
645:Main article:
618:
615:
612:
611:
584:
582:
575:
569:
566:
513:magnetic field
484:
481:
401:
398:
350:
347:
338:high frequency
287:Philipp Lenard
282:
279:
243:
240:
238:
235:
229:and removing "
207:night-fighters
120:magnetic field
98:used in early
41:
9:
6:
4:
3:
2:
3880:
3869:
3866:
3864:
3861:
3859:
3856:
3854:
3851:
3849:
3846:
3844:
3841:
3839:
3836:
3835:
3833:
3816:
3815:mercury relay
3813:
3811:
3808:
3807:
3806:
3803:
3801:
3798:
3796:
3793:
3791:
3788:
3786:
3783:
3779:
3776:
3775:
3774:
3771:
3770:
3768:
3766:
3762:
3754:
3751:
3750:
3749:
3746:
3744:
3741:
3739:
3736:
3734:
3731:
3729:
3726:
3724:
3721:
3717:
3714:
3712:
3709:
3708:
3707:
3704:
3702:
3699:
3697:
3694:
3692:
3689:
3685:
3682:
3680:
3677:
3675:
3672:
3671:
3669:
3668:
3666:
3662:
3656:
3653:
3651:
3648:
3644:
3641:
3640:
3639:
3638:Potentiometer
3636:
3635:
3633:
3629:
3623:
3620:
3618:
3615:
3613:
3610:
3608:
3605:
3603:
3600:
3598:
3595:
3593:
3590:
3588:
3585:
3583:
3580:
3578:
3575:
3573:
3570:
3569:
3567:
3565:
3561:
3555:
3554:Williams tube
3552:
3550:
3547:
3545:
3542:
3540:
3537:
3535:
3532:
3530:
3527:
3525:
3522:
3520:
3517:
3515:
3512:
3510:
3507:
3506:
3504:
3502:
3498:
3492:
3489:
3486:
3483:
3481:
3478:
3476:
3473:
3471:
3468:
3465:
3462:
3460:
3457:
3454:
3451:
3449:
3446:
3443:
3440:
3439:
3437:
3434:
3430:
3426:
3420:
3417:
3415:
3412:
3410:
3407:
3405:
3402:
3400:
3397:
3394:
3391:
3389:
3386:
3384:
3381:
3379:
3376:
3374:
3373:Fleming valve
3371:
3369:
3366:
3364:
3361:
3359:
3356:
3354:
3351:
3349:
3346:
3344:
3341:
3340:
3338:
3336:
3332:
3326:
3323:
3321:
3318:
3316:
3313:
3311:
3308:
3306:
3303:
3301:
3298:
3296:
3293:
3291:
3288:
3286:
3283:
3281:
3278:
3276:
3273:
3272:
3270:
3268:
3264:
3254:
3251:
3249:
3246:
3244:
3241:
3239:
3236:
3233:
3230:
3227:
3224:
3222:
3219:
3216:
3213:
3211:
3208:
3206:
3203:
3201:
3200:Photodetector
3198:
3196:
3193:
3190:
3187:
3185:
3182:
3179:
3176:
3174:
3171:
3169:
3168:Memtransistor
3166:
3164:
3161:
3159:
3156:
3153:
3150:
3148:
3145:
3142:
3139:
3137:
3134:
3132:
3129:
3127:
3124:
3122:
3119:
3118:
3116:
3110:
3104:
3101:
3099:
3096:
3094:
3091:
3089:
3086:
3084:
3081:
3078:
3075:
3072:
3069:
3066:
3063:
3061:
3058:
3055:
3052:
3050:
3047:
3046:
3044:
3042:
3038:
3031:
3028:
3026:
3023:
3020:
3017:
3014:
3011:
3009:
3006:
3004:
3001:
2997:
2994:
2993:
2991:
2988:
2984:
2981:
2979:
2976:
2975:
2973:
2970:
2968:
2965:
2963:
2960:
2957:
2954:
2953:
2951:
2949:
2943:
2937:
2934:
2932:
2929:
2926:
2923:
2921:
2918:
2915:
2912:
2909:
2906:
2904:
2901:
2899:
2896:
2893:
2890:
2887:
2884:
2881:
2878:
2876:
2873:
2870:
2867:
2864:
2861:
2859:
2856:
2854:
2851:
2849:
2846:
2844:
2841:
2839:
2836:
2835:
2833:
2831:
2825:
2822:
2820:
2817:Semiconductor
2814:
2810:
2803:
2798:
2796:
2791:
2789:
2784:
2783:
2780:
2774:
2764:
2760:
2758:
2748:
2744:
2742:
2732:
2728:
2726:
2716:
2712:
2710:
2700:
2696:
2694:
2684:
2680:
2678:
2677:
2666:
2662:
2653:
2649:
2648:
2644:
2643:
2639:
2636:
2633:
2629:
2626:
2623:
2620:
2617:
2615:
2611:
2608:
2605:
2603:
2600:
2599:
2595:
2594:
2575:
2569:
2565:
2564:
2556:
2548:
2542:
2526:
2522:
2518:
2511:
2495:
2491:
2487:
2481:
2465:
2461:
2457:
2450:
2442:
2438:
2434:
2430:
2426:
2422:
2419:(3): 200–10.
2418:
2414:
2407:
2398:
2391:
2384:
2372:
2368:
2364:
2357:
2350:
2345:
2329:
2325:
2321:
2317:
2313:
2309:
2302:
2286:
2282:
2278:
2271:
2263:
2256:
2249:
2245:
2242:
2236:
2224:
2220:
2215:
2211:
2207:
2202:
2198:
2193:
2188:
2184:
2179:
2178:
2177:
2176:
2172:
2171:
2164:
2160:
2156:
2152:
2149:(5): 658–70.
2148:
2145:(in German).
2144:
2138:
2134:
2130:
2125:
2122:(2): 395–407.
2121:
2117:
2112:
2111:
2110:
2109:
2105:
2104:
2100:
2092:
2088:
2084:
2080:
2076:
2072:
2071:Physics Today
2065:
2057:
2050:
2048:
2039:
2036:(in German).
2035:
2028:
2019:
2015:
2012:
2008:
2004:
2001:(in German).
2000:
1995:
1992:
1988:
1985:
1978:
1973:
1969:
1965:
1961:
1956:
1955:
1951:
1941:
1937:
1932:
1929:
1925:
1920:
1919:
1915:
1906:
1902:
1899:
1898:Metapress.com
1893:
1889:
1885:
1881:
1877:
1873:
1870:(2): 204–05.
1869:
1865:
1860:
1855:
1850:
1846:
1842:
1839:(4816): 625.
1838:
1834:
1830:
1825:
1824:
1820:
1810:
1806:
1802:
1798:
1795:(9): 715–23.
1794:
1790:
1786:
1781:
1777:
1773:
1769:
1765:
1761:
1757:
1753:
1748:
1747:
1743:
1727:
1723:
1719:
1712:
1704:
1701:(in German).
1700:
1696:
1689:
1681:
1674:
1664:
1662:9783642507892
1658:
1654:
1650:
1649:
1643:
1640:
1639:
1635:
1627:
1623:
1619:
1615:
1611:
1607:
1603:
1599:
1595:
1591:
1587:
1583:
1579:
1572:
1565:
1564:9780408001687
1561:
1557:
1551:
1549:
1547:
1530:
1526:
1522:
1516:
1508:
1504:
1500:
1496:
1492:
1488:
1487:Physics Today
1481:
1465:
1461:
1457:
1451:
1449:
1447:
1445:
1428:
1424:
1420:
1413:
1407:
1403:
1399:
1396:
1390:
1382:
1376:
1372:
1368:
1364:
1357:
1355:
1336:
1332:
1328:
1321:
1314:
1312:
1296:
1292:
1288:
1281:
1279:
1277:
1275:
1273:
1271:
1269:
1261:
1256:
1240:
1236:
1230:
1222:
1216:
1212:
1205:
1198:
1192:
1190:
1185:
1176:
1173:
1171:
1168:
1166:
1163:
1161:
1158:
1156:
1153:
1151:
1148:
1146:
1142:
1139:
1137:
1134:
1133:
1127:
1125:
1121:
1117:
1113:
1108:
1105:
1103:
1099:
1095:
1087:
1083:
1074:
1072:
1068:
1064:
1059:
1057:
1053:
1049:
1044:
1043:
1037:
1033:
1027:
1025:
1021:
1017:
1013:
1008:
1006:
1002:
1001:Alan Blumlein
998:
994:
990:
986:
982:
978:
976:
975:"Taffy" Bowen
971:
967:
963:
959:
955:
951:
947:
943:
937:
932:
930:
926:
921:
919:
915:
911:
908:
903:
899:
895:
886:
878:
871:
867:
863:
859:
855:
851:
848:
844:
840:
839:night fighter
836:
832:
828:
827:Hans Hollmann
824:
820:
816:
812:
807:
805:
801:
795:
793:
789:
785:
784:Lee De Forest
781:
777:
772:
770:
769:electron mass
766:
756:
754:
750:
746:
742:
741:metal halides
738:
734:
730:
720:
718:
714:
713:cryogenically
709:
708:
703:
695:
691:
686:
677:
675:
670:
666:
660:
658:
654:
648:
640:
636:
632:
628:
623:
608:
598:
592:
588:
585:This section
583:
579:
574:
573:
565:
562:
556:
552:
548:
546:
542:
538:
532:
530:
526:
522:
521:Lorentz force
518:
514:
510:
506:
498:
494:
489:
480:
478:
474:
468:
466:
460:
456:
454:
450:
446:
442:
438:
434:
425:
420:
416:
414:
410:
408:
397:
393:
389:
387:
383:
379:
374:
368:
364:
360:
355:
346:
343:
339:
334:
332:
328:
323:
320:
314:
312:
311:electromagnet
308:
307:Lorentz force
302:
300:
296:
295:Lee de Forest
292:
288:
278:
276:
272:
268:
263:
261:
257:
253:
249:
234:
232:
228:
223:
218:
216:
212:
208:
204:
200:
196:
192:
187:
184:
180:
176:
172:
171:Hans Hollmann
168:
164:
160:
156:
155:Lee de Forest
152:
147:
145:
141:
137:
133:
129:
125:
121:
117:
113:
109:
105:
101:
97:
93:
85:
81:
77:
73:
72:(top, bottom)
69:
64:
56:
47:
38:
34:
30:
19:
3858:Vacuum tubes
3572:Cold cathode
3539:Storage tube
3447:
3429:Vacuum tubes
3378:Neutron tube
3353:Beam tetrode
3335:Vacuum tubes
2920:Power MOSFET
2772:
2756:
2740:
2724:
2708:
2692:
2674:
2577:. Retrieved
2562:
2555:
2529:. Retrieved
2520:
2510:
2498:. Retrieved
2489:
2480:
2468:. Retrieved
2464:the original
2459:
2449:
2416:
2412:
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2396:
2390:
2382:
2375:. Retrieved
2366:
2356:
2344:
2332:. Retrieved
2328:the original
2315:
2311:
2301:
2289:. Retrieved
2280:
2270:
2261:
2255:
2241:"Magnetron,"
2235:
2222:
2218:
2212:(4): 652–59.
2209:
2205:
2196:
2189:(6): 715–41.
2186:
2182:
2146:
2142:
2132:
2128:
2119:
2115:
2099:
2077:(7): 60–67.
2074:
2070:
2064:
2055:
2037:
2033:
2027:
2002:
1998:
1967:
1966:(in Czech).
1963:
1950:
1939:
1935:
1927:
1923:
1914:
1867:
1863:
1836:
1832:
1819:
1792:
1788:
1762:(1): 31–57.
1759:
1755:
1742:
1730:. Retrieved
1721:
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1698:
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1679:
1673:
1652:
1647:
1634:
1585:
1581:
1571:
1555:
1533:. Retrieved
1524:
1515:
1493:(7): 60–67.
1490:
1486:
1480:
1468:. Retrieved
1459:
1431:. Retrieved
1422:
1412:
1405:
1389:
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1342:. Retrieved
1330:
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1299:. Retrieved
1290:
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1243:. Retrieved
1229:
1210:
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1196:
1109:
1106:
1091:
1060:
1041:
1028:
1012:World War II
1009:
979:
948:agreed that
939:
934:
922:
912:
907:James Sayers
898:John Randall
891:
815:World War II
808:
796:
773:
762:
726:
707:mode stirrer
705:
699:
669:marine radar
661:
650:
602:
586:
568:Applications
557:
553:
549:
533:
502:
473:phased array
469:
461:
457:
429:
412:
405:
403:
394:
390:
381:
377:
375:
371:
362:
358:
335:
324:
315:
303:
284:
267:control grid
264:
245:
219:
195:John Randall
190:
188:
148:
91:
89:
75:
71:
3738:Transformer
3480:Sutton tube
3320:Charge pump
3173:Memory cell
3103:Zener diode
3065:Laser diode
2948:transistors
2830:transistors
2596:Information
2135:(2): 22–27.
1118:mixed with
896:in the UK,
823:wavelengths
776:Albert Hull
774:In the US,
729:sulfur lamp
637:and a 1N21
248:vacuum tube
159:Albert Hull
96:vacuum tube
3832:Categories
3810:reed relay
3800:Parametron
3733:Thermistor
3711:resettable
3670:Connector
3631:Adjustable
3607:Nixie tube
3577:Crossatron
3544:Trochotron
3519:Iconoscope
3514:Charactron
3491:X-ray tube
3363:Compactron
3343:Acorn tube
3300:Buck–boost
3221:Solaristor
3083:Photodiode
3060:Gunn diode
3056:(CLD, CRD)
2838:Transistor
2747:US 2611094
2731:US 2444152
2715:US 2408236
2699:US 2357314
2683:US 2357313
2665:US 2315313
2652:US 2123728
2602:Magnetrons
1970:: 378–80.
1423:zipcon.net
1344:2009-08-23
1301:2007-08-16
1181:References
902:Harry Boot
862:Harry Boot
605:March 2023
547:are used.
453:LC circuit
319:hysteresis
199:Harry Boot
183:Telefunken
112:microwaves
3773:Capacitor
3617:Trigatron
3612:Thyratron
3602:Neon lamp
3529:Monoscope
3409:Phototube
3393:Pentagrid
3358:Barretter
3243:Trancitor
3238:Thyristor
3163:Memristor
3088:PIN diode
2865:(ChemFET)
2763:GB 879677
2377:9 October
2349:Fine 2019
2005:: 172–80.
1892:189766320
1705:: 856–64.
1610:0028-0836
1260:Fine 2019
1245:23 August
1122:in their
1102:cataracts
997:H2S radar
819:microwave
733:waveguide
694:heat sink
597:talk page
537:impedance
525:waveguide
509:evacuated
465:waveguide
445:capacitor
409:magnetron
275:amplifier
252:electrons
157:in 1906.
140:amplifier
116:electrons
18:Magnetron
3795:Inductor
3765:Reactive
3743:Varistor
3723:Resistor
3701:Antifuse
3587:Ignitron
3582:Dekatron
3470:Klystron
3459:Gyrotron
3388:Nuvistor
3305:Split-pi
3191:(MOS IC)
3158:Memistor
2916:(MuGFET)
2910:(MOSFET)
2882:(FinFET)
2628:Archived
2610:Archived
2541:cite web
2525:Archived
2494:Archived
2371:Archived
2285:Archived
2244:Archived
2014:Archived
1987:Archived
1901:Archived
1809:51641488
1726:Archived
1618:13165726
1529:Archived
1464:Archived
1427:Archived
1398:Archived
1393:Ma, L. "
1335:Archived
1295:Archived
1291:BBC News
1239:Archived
1150:Klystron
1141:Yoji Ito
1130:See also
1124:filament
1120:tungsten
1086:ISO 7010
1067:klystron
1040:FuG 350
1020:Japanese
835:klystron
723:Lighting
717:hamsters
545:klystron
449:inductor
433:revolver
132:klystron
70:magnets
33:Metatron
29:Megatron
3696:Ferrite
3664:Passive
3655:Varicap
3643:digital
3592:Krytron
3414:Tetrode
3399:Pentode
3253:Varicap
3234:(3D IC)
3210:RF CMOS
3114:devices
2888:(FGMOS)
2819:devices
2645:Patents
2579:24 June
2441:3068822
2433:6071133
2334:22 June
2151:Bibcode
2079:Bibcode
1872:Bibcode
1841:Bibcode
1764:Bibcode
1626:4242031
1590:Bibcode
1495:Bibcode
1116:thorium
1096:of the
962:Wembley
759:History
715:frozen
680:Heating
657:antenna
529:antenna
505:cathode
363:(right)
256:cathode
231:clutter
201:at the
181:(GEC),
175:Philips
118:with a
106:and in
3728:Switch
3419:Triode
3383:Nonode
3348:Audion
3228:(SITh)
3112:Other
3079:(OLED)
3041:Diodes
2992:(LET)
2974:(FET)
2946:Other
2894:(IGBT)
2871:(CMOS)
2858:BioFET
2853:BiCMOS
2768:
2752:
2736:
2720:
2704:
2688:
2670:
2657:
2570:
2521:US EPA
2439:
2431:
1890:
1833:Nature
1807:
1659:
1624:
1616:
1608:
1582:Nature
1562:
1377:
1333:: 10.
1217:
1114:, and
1056:London
1016:German
966:London
831:Berlin
809:While
737:sulfur
589:about
561:S band
493:alnico
386:plates
359:(left)
271:triode
191:cavity
151:Audion
68:alnico
50:shown.
3853:Radar
3805:Relay
3778:types
3716:eFUSE
3487:(TWT)
3475:Maser
3466:(IOT)
3455:(CFA)
3444:(BWO)
3368:Diode
3315:SEPIC
3295:Boost
3248:TRIAC
3217:(SCR)
3180:(MOV)
3154:(LEC)
3073:(LED)
3032:(UJT)
3021:(SIT)
3015:(PUT)
2958:(BJT)
2927:(TFT)
2903:LDMOS
2898:ISFET
2531:5 May
2500:5 May
2470:5 May
2291:5 May
1954:See:
1938:[
1888:S2CID
1805:S2CID
1746:See:
1732:5 May
1651:[
1638:See:
1622:S2CID
1535:5 May
1470:5 May
1433:5 May
1338:(PDF)
1323:(PDF)
1155:Maser
1042:Naxos
942:Nazis
811:radar
745:HEMTs
653:radar
651:In a
633:tube
617:Radar
541:radar
451:: an
260:anode
134:or a
100:radar
76:(top)
35:, or
3748:Wire
3706:Fuse
3290:Buck
3143:(IC)
3131:DIAC
3067:(LD)
2936:UMOS
2931:VMOS
2848:PMOS
2843:NMOS
2828:MOS
2581:2011
2568:ISBN
2547:link
2533:2018
2502:2018
2472:2018
2437:PMID
2429:OSTI
2379:2017
2336:2012
2293:2018
1734:2018
1657:ISBN
1614:PMID
1606:ISSN
1560:ISBN
1537:2018
1472:2018
1435:2018
1375:ISBN
1247:2009
1215:ISBN
1094:lens
1069:and
1018:and
1003:and
900:and
860:and
437:Colt
197:and
189:The
90:The
3310:Ćuk
2421:doi
2320:doi
2159:doi
2147:393
2087:doi
1972:doi
1880:doi
1849:doi
1837:193
1797:doi
1772:doi
1598:doi
1586:173
1503:doi
1367:doi
1098:eye
1032:H2S
914:GEC
829:in
700:In
411:or
250:),
161:of
153:by
3834::
3684:RF
3433:RF
2543:}}
2539:{{
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2073:.
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2038:24
2003:32
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2081::
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1993:.
1980:.
1974::
1907:.
1894:.
1882::
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