Optically driven field emission array for THZ amplifiers

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Carbon nanotube based cathodes for microwave amplifiers

We have studied two different kinds of electron tubes using a cold field emission cathode as the electron source. This cathode is an array of vertically aligned multiwall carbon nanotubes. The first device is a triode. With this device, we demonstrated the modulation at 32 GHZ of a 1.4 A/cm2 peak current density with a 82% modulation ratio. The second device is a traveling wave tube. For this device, the objective is to test a cathode delivering a 2 A/cm 2 electron beam. ©2009 IEEE

The European Project OPTHER for the development of a THz tube amplifier

The European project OPTHER - Optically Driven THz Amplifiers, is focused on the realization of a THz amplifier. This device aims to overcome the actual limitations of THz sources in terms of emitted power, opening the way to the use of THz in monitoring security systems. Two alternative schemes are under study for amplification. In the first one (THz drive signal amplifier) the continuous wave electron beam emitted by the CNT cathode is modulated by the electric field in the interaction structure driven by a THz signal (generated by QCL or laser mixing). In the second one (optically modulated beam THz amplifier), the CNT cathode emits bunches of electrons at the THz rate. Those bunches are transmitted to the interaction structure and generate the amplified output signal

European Research on THz Vacuum Amplifiers

The OPTHER (OPtically Driven TeraHertz AmplifiERs) project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within this project is a consolidation of efforts at the international level from the main players of the European research, academy and industry in vacuum electronics. This paper describes the status of the project and progress towards the THz amplifier realization

Towards a THz Backward Wave Amplifier in European OPTHER project

Within the EC funded international project OPTHER (OPtically Driven TeraHertz AmplifiERs) a considerable technological effort is being undertaken, in terms of technological development, THz device design and integration. The ultimate goal is to develop a miniaturised THz amplifier based on vacuum-tube principles The main target specifications of the OPTHER amplifier are the following: - Operating frequency: in the band 0.3 to 2 THz - Output power: > 10 mW (10 dBm) - Gain: 10 to 20 dB. The project is in the middle of its duration. Design and simulations have shown that these targets can be met with a proper device configuration and careful optimization of the different parts of the amplifier. Two parallel schemes will be employed for amplifier realisation: THz Drive Signal Amplifier and Optically Modulated Beam THz Amplifier