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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 ...
He was the leader of a group working on the cavity magnetron from April 1940 in north-west London. [7] The cavity magnetron was producing power of around 500W (E1188 version). Eric Megaw changed the design, coating the cathode with oxides (E1189 version) [ 8 ] and eight segments from six, to increase the power to 100 kW by September 1940 ...
The magnetron was initially limited to aircraft operating over the UK or sea, so that if the aircraft was lost the magnetron would not fall into German hands. However, as the war progressed several new uses for the magnetron were developed, notably ground-mapping systems like the H2S radar .
The resonant cavity magnetron continued to evolve at the Rad Lab. A team led by I.I. Rabi first extended the operation of the magnetron from 10-cm (called S-band), to 6-cm (C-band), then to 3-cm (X-band), and eventually to 1-cm (K-band). To keep pace, all of the other radar sub-systems also were evolving continuously.
A normal magnetron is like a whistle, where the audio note produced is dependant on the size of the whistle's internal dimensions. A resonant cavity magnetron however is like a whistle with a pea in it, the rotary motion of the pea produces multiple notes of a much higher frequency.
Cavity resonators are widely used as the frequency determining element in microwave oscillators. Their resonant frequency can be tuned by moving one of the walls of the cavity in or out, changing its size. An illustration of the electric and magnetic field of one of the possible modes in a cavity resonator.
Name Date invented Invented by Original purpose Civilian uses ASDIC: 1910s United Kingdom. France. Submarine detection Sonar: Radar: mid-1930s United Kingdom [1] [2]: Early warning radar, air defence systems
In radio-frequency engineering and communications engineering, a waveguide is a hollow metal pipe used to carry radio waves. [1] This type of waveguide is used as a transmission line mostly at microwave frequencies, for such purposes as connecting microwave transmitters and receivers to their antennas, in equipment such as microwave ovens, radar sets, satellite communications, and microwave ...