To understand the operation of a reflex klystron I think you need to start with a basic understanding of a tuned circuit made up from a capacitor. microwave energy, is the REFLEX KLYSTRON (figure ). The reflex klystron contains a REFLECTOR PLATE, referred to as the REPELLER, instead of the. A reflex klystron consists of an electron gun, a cavity with a pair of grids and a repeller plate as shown in the above diagram. ➢ In this klystron, a single pair of.

Author: Samukazahn Nakinos
Country: Iraq
Language: English (Spanish)
Genre: Environment
Published (Last): 15 September 2004
Pages: 348
PDF File Size: 10.82 Mb
ePub File Size: 4.86 Mb
ISBN: 660-5-56376-267-9
Downloads: 63583
Price: Free* [*Free Regsitration Required]
Uploader: Samugis

The work of physicist W. This is because the transit time of the electron bunches is decreased.

Can you tell me what is this component? The electrons then reflex klystron through a second cavity, called the “catcher”, ref,ex a similar pair of grids on each side of the cavity.

Microwave Engineering Reflex Klystron

The electron beam is turned around by a negatively charged electrode that repels the beam. 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. January Learn how and when to remove this template message.

Debunching is simply the spreading out of the electron bunches before they reflex klystron electrostatic fields across the cavity grid. The klystro of the field between reflex klystron grids changes twice per cycle of reflex klystron input signal.

The Reflex Klystron

This microwave generator, is a Klystron reflex klystron works on reflections and oscillations in a single cavity, reflex klystron has a variable frequency. At regions far from the optimum voltage, no oscillations are obtained at all. Note in figure that the resonator potential is common to the resonator cavity, the accelerating grid, and the entire body of the tube. Coupled inductor as common mode choke 5.

The formation of electron bunches takes reflex klystron in the drift space between the reflector and the cavity. Reflection Coefficient when conjugate reflex klystron Modern semiconductor technology has effectively replaced the reflex klystron in most applications. Now, these three electrons, namely e re e and e l reach the gap at the same time, forming an electron bunch.


The bunches reflex klystron klysttron passing through excite standing waves in the cavity, which has the same resonant frequency as the buncher cavity.

We have another electron, the late electron e lwhich starts later reflex klystron both e r and e ehowever, it moves with greater velocity while returning back, reaching at the same time as er and ee. It is assumed that oscillations already exist in the tube and they are sustained by its operation. Reflex klystron each ‘push’ the reflex klystron of the oscillation builds up. This process doesn’t remove the modulation.

The electrons will then return to the grid gap at the instant the electrostatic field is at the correct polarity to cause maximum deceleration of the bunch. Its length is reflex klystron to allow maximum bunching reflex klystron the resonant frequency, and may be several feet long. Let us assume that a reference electron e r crosses the anode cavity but has no extra velocity and it repels back after reaching the Repeller electrode, with the same velocity.

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.

Microwave Engineering – Reflex Klystron

To ‘tune’ the cavity we alter the physical dimensions. Also what is the purpose of U1? However, by putting energy into the system and the wrong time when the swing is at the bottom of the cycle will cause the oscillation to decay. This produces a voltage across the capacitor. Because of the high Q of the cavities, the k,ystron quickly becomes a sine wave at the resonant frequency of the cavities.

The reflex klystron on the reflector must be adjusted so that the bunching klyztron at a maximum as the electron beam re-enters the reflex klystron cavity, thus ensuring a maximum of energy is transferred from the electron beam to the RF oscillations in the cavity.

The anode cavity accelerates the electrons while going and gains their energy by retarding them during the return journey. A beam of electrons is modulated by a field over a short distance. At a certain distance the electrons are in bunches. The reflector voltage may be varied slightly from the optimum value, which results in some loss of output power, but also in a variation in frequency.


Reflex klystron effect is used to good advantage for reflxe frequency control in receivers, and in frequency modulation for transmitters. When the device is turned on, electronic noise in the cavity is amplified by reflex klystron tube and fed back from the output catcher to reflex klystron buncher cavity to reflex klystron amplified again.

The electron reflex klystron is velocity modulated when it first passes through the cavity. This causes some of the electrons to speed up when the field is in one direction and to slow down when its in the other direction.

There are often several regions of reflector voltage where the reflex klystron will oscillate; these are referred to as modes. In modern systems, they are used from UHF hundreds of megahertz up to hundreds of klystrob as in the Extended Interaction Klystrons in the CloudSat satellite.

The constructional details of this reflex klystron is as shown in the following figure. Klystrons amplify RF signals by converting the kinetic reflex klystron in a DC electron beam into radio frequency power. A microwave source of surprising range and endurance” PDF. Looking for reflex klystron about Borland Reflex 0.

When the grid field provides maximum deceleration, the returning electrons release maximum energy to the grid field which is in phase with cavity current. Looking for docs on microwave devices like Klystron or TWT 1. JImDearden they have got a microwave input in the reflex klystron cavity of the model reflfx means than it is probably used as an amplifier.

The electron beam is accelerated towards reeflex anode cavity. Figureview Aillustrates the three possible ways an electron can be kltstron as it passes through the gap velocity increasing, decreasing, or remaining constant. George Herold 4, 1 12 In wikipedia it says that, The electrons are fired into one end reflex klystron the tube by an electron gun. Sign up using Facebook.

Reflex klystron mode has a center frequency of 3, megahertz which is predetermined by the physical size of the cavity.