Terahertz radiation

Tapering

Electrical engineering

Optics

Physics

Computer graphics (images)

Engineering

Traveling-wave tube

Electron

Magnet

Voltage

Beam (structure)

Materials science

Amplifier

Duty cycle

Bandwidth (computing)

Computer science

Optoelectronics

Quantum mechanics

Telecommunications

Cathode ray

IEEE Electron Device Letters

This letter presents the research progress of a pulsed G-band 50 W traveling wave tube (TWT) with pencil beam focused by periodic permanent magnet (PPM). Three approaches have been combined to improve the tube's operation performances including setting the operating point near the cutoff frequency, using the folded waveguide (FWG) slow wave structure (SWS) with modified circular bends (MCBs), and adopting phase velocity tapering (PVT) technique. The measured output power can be over 50 W at 5% duty cycle with a bandwidth of 3.6 GHz when the beam voltage is 24.25 kV and the beam current is 59 mA. Corresponding electronic efficiency and gain are higher than 3.5% and 35 dB, respectively. The results provide a demonstration of a compact terahertz amplifier with high power, high electronic efficiency and significant bandwidth.

Demonstration of a Pulsed G-Band 50-W Traveling Wave Tube