Travelling Wave Tube Amplifier Operation

It is a special type of vacuum tube that offers an operating frequency ranging between 300 mhz to 50 ghz.

Travelling wave tube amplifier operation.

The traveling wave tube can be used as a medium or high power microwave amplifier. A travelling wave tube is a high power amplifier used for the amplification of microwave signals up to a wide range. Twt operates on lower efficiency. The twt belongs to a category of linear beam tubes such as the klystron in which the radio wave is amplified by absorbing power from a beam of electrons as it.

When the wave on the axial electric field is at positive antinode the electron from the electron beam moves in the opposite direction. Travelling wave tube has wider bandwidth of operation. The heated cathode at one end of the tube produces a beam of electrons and is attracted to the collector at the other end of the tube. The twt because of its construction and working principle has enormous bandwidths and low noise.

Travelling wave tube operation in order to design a helix type traveling wave tube amplifier twta it is necessary to understand the operating physics of a travelling wave tube twt. Has a long life when compared to. Frequency of operation is from 300mhz to 50 ghz. In this video i have explained travelling wave tube with following topics.

Structure of travelling wave tube. There two types of twt that is helix and coupled cavity. Unlike the klystron however it is a device in which the interaction between the beam and the rf field is continuous. Like the multicavity klystron the traveling wave tube working is a linear beam tube used as a microwave amplifier.

A class d i e pulse mode on off amplifier formed from an mwcnt array cathode was also successfully operated at 1 5 ghz with a peak current density of 12 a cm 2 314. The functionalities of these. Traveling wave tube working twt. Twit are vacuum tubes used as high gain low noise wide bandwidth microwave wideband amplifiers a twt is capable of gains from 40 to 70 db with bandwidths exceeding two octaves.

Travelling wave tubes are non resonant structures that offer continuous interaction of applied rf field with the electron beam over the entire length of the tube. Operation of travelling wave tube the anode plates when at zero potential which means when the axial electric field is at a node the electron beam velocity remains unaffected. Operational parameters of travelling wave tube 3. This chapter provides the basic description of the twta structure and its various components.

Travelling wave has high power output. A bandwidth of 1 octave is one in which the upper frequency is twice the lower frequency. Basics of travelling wave tube 2. A traveling wave tube twt pronounced twit or traveling wave tube amplifier twta pronounced tweeta is a specialized vacuum tube that is used in electronics to amplify radio frequency rf signals in the microwave range.

More recently a 32 ghz directly modulated cnt array cathode under class a i e sine wave operation with over 90 modulation depth has also been demonstrated.