Classification of microwave tubes
What are microwave tubes?
What is mean by O type and M type tubes?
Static magnetic field is perpendicular to the electric field. Magnetron is the M type Tube. Electron travel in curved path. O type Tubes. Static magnetic field is same direction to the electric field.
What is microwave linear beam tubes?
Linear-beam tubes are the most versatile devices used for the generation and amplification of energy at microwave frequencies. The usual forms are klystrons and travelling-wave tubes (TWTs). High-power klystrons and coupledcavity TWTs are widely used in radars and communications transmitters.
Which modulation method is used in microwave tubes?
Velocity-modulated tubes are microwave tubes using transit time in the conversion of dc power to radio-frequency power. The interchange of power is accomplished by using the principle of electron velocity modulation and low-loss resonant cavities in (or near the electron beam of) the microwave tube.
What are O type tubes give examples?
Klystrons and TWT’s are linear beam or O type tubes in which the accelerating electric field in the same direction as the static magnetic field used to focus the electron beam. A klystron is a vacuum tube that can be used either as a generator or as an amplifier of power at microwave frequencies.
What is the use of klystron?
Klystrons are used in ultrahigh-frequency (UHF) circuits, such as UHF television transmission, and for microwave radar sources, where they can produce oscillations up to 400 gigahertz, in the short microwave range.
What do magnetrons do?
Magnetrons are capable of generating extremely high frequencies and also short bursts of very high power. They are an important source of power in radar systems and in microwave ovens.
How does a Travelling wave tube work?
A Travelling Wave Tube amplifies a modulated electromagnetic wave in order to transmit data. Inside the vacuum envelope, the electromagnetic wave interacts with an electron beam. Because both travel at almost the same speed, electrons transmit their kinetic energy to the wave, an effect known as the Cherenkov effect.
What is velocity modulation?
Definition of velocity modulation
: modification of the velocity of a stream of electrons by imparting alternate accelerations and decelerations to the electrons in such a way that they are caused to bunch together with the result that each bunch causes a cycle of current as it passes an output electrode.
Why TWT is adopted to the multicavity klystron because it?
Has a greater bandwidth. Has a higher number of modes. Produces a higher output power.
What are the two basic types of traveling wave tubes?
A travelling wave tube is basically of two types one is helix type and the other is coupled cavity.
What is the difference between Travelling wave tube and magnetron?
Magnetron tubes are representative of an entirely different kind of tube than the klystron. Whereas the latter tubes use a linear electron beam, the magnetron directs its electron beam in a “circular pattern” by means of a strong magnetic field.
What is the difference between TWT and klystron?
The main difference between the operation of a TWT and a klystron is that while the TWTs’ circuit operates in a non-resonant mode, the klystrons’ circuit operates in a resonant mode. Therefore, the electronic conversion efficiency is relatively low for TWTs and fairly high for klystrons.
Why is it called a traveling wave tube?
Travelling wave tube is a cylindrical structure which contains an electron gun from a cathode tube. It has anode plates, helix and a collector. RF input is sent to one end of the helix and the output is drawn from the other end of the helix. An electron gun focusses an electron beam with the velocity of light.
What does TWTs stand for?
Noun. TWT (plural TWTs) (electronics) Abbreviation of travelling-wave tube. or traveling-wave tube.
What is BWO in microwave?
A backward wave oscillator (BWO), also called backward wave tube, is a vacuum tube that is used to generate microwaves up to the terahertz range. Belonging to the traveling-wave tube family, it is an oscillator with a wide electronic tuning range.
Why helix is used in TWT?
Explanation: A helix in TWT plays an important role as a delay line, slowing down the RF signals travelling at a speed of light near the same speed along the tube as the electron beam.
What are the characteristics of TWT?
The Traveling Wave Tube (twt) is a high-gain, low-noise, wide-bandwidth microwave amplifier. It is capable of gains greater than 40 dB with bandwidths exceeding an octave. (A bandwidth of 1 octave is one in which the upper frequency is twice the lower frequency.)