The CV67 type of klystron tuning of reflex klystron oscillators forex used in early 10 cm radar systems as a local oscillator. Thanks to Frank Philipse for supplying the above PDF datasheet. Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn’t yet, but we’re working on it!
See more info or our list of citable articles. From Wikipedia, the free encyclopedia For the high-speed switching arc-discharge tube, see Krytron. High-power klystron used at the Canberra Deep Space Communications Complex. Klystrons used for generating heterodyne reference frequencies in radar receivers are about the size of a whiteboard pen.
All modern klystrons are amplifiers, since reflex klystrons, which were used as oscillators in the past, have been surpassed by alternative technologies. Greek verb referring to the action of waves breaking against a shore, and the end of the word electron. The brothers Russell and Sigurd Varian of Stanford University are the inventors of the klystron. Their prototype was completed in August 1937. US and UK researchers working on radar equipment. Hansen was instrumental in the development of klystron and was cited by the Varian brothers in their 1939 paper. Allies used the far more powerful but frequency-drifting technology of the cavity magnetron for microwave generation.
Klystrons amplify RF signals by converting the kinetic energy in a DC electron beam into radio frequency power. This beam is then passed through an input cavity. In the two-chamber klystron, the electron beam is injected into a resonant cavity. The electron beam, accelerated by a positive potential, is constrained to travel through a cylindrical drift tube in a straight path by an axial magnetic field. While passing through the first cavity, the electron beam is velocity modulated by the weak RF signal. The two-cavity amplifier klystron is readily turned into an oscillator klystron by providing a feedback loop between the input and output cavities.
The electrons are fired into one end of the tube by an electron gun. After passing through the resonant cavity they are reflected by a negatively charged reflector electrode for another pass through the cavity, where they are then collected. The electronic tuning range of the reflex klystron is usually referred to as the variation in frequency between half power points—the points in the oscillating mode where the power output is half the maximum output in the mode. Modern semiconductor technology has effectively replaced the reflex klystron in most applications. In all modern klystrons, the number of cavities exceeds two. A larger number of cavities may be used to increase the gain of the klystron, or to increase the bandwidth. Some klystrons have cavities that are tunable.
Tuning a klystron is delicate work which, if not done properly, can cause damage to equipment or injury to the technician. By adjusting the frequency of individual cavities, the technician can change the operating frequency, gain, output power, or bandwidth of the amplifier. The technician must be careful not to exceed the limits of the graduations, or damage to the klystron can result. Manufacturers generally send a card with the unique calibrations for a klystron’s performance characteristics, that lists the graduations to be set to attain any of a set of listed frequencies. Other precautions taken when tuning a klystron include using nonferrous tools. Precautions are routinely taken when transporting klystron devices in aircraft, as the intense magnetic field can interfere with magnetic navigation equipment.
Special overpacks are designed to help limit this field “in the field,” and thus allow such devices to be transported safely. In an optical klystron the cavities are replaced with undulators. The electron gun, the drift tube and the collector are still used. The floating drift tube klystron has a single cylindrical chamber containing an electrically isolated central tube. Electrically, this is similar to the two cavity oscillator klystron with a lot of feedback between the two cavities.