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The development's results of the 7-beam Ka-band TWT with high electronic efficiency (∼20%), the gain coefficient (∼50dB) and a broad band operating frequency (∼2.5%) are presented.
Beam Optics Analyzer (BOA) provides a new capability to model the RF modulated electron beam entering and exiting the output cavity of an Inductive Power Tube (IOT). For a given Q factor, we will present numerical results of a simple cylindrical cavity resonated by a RF modulated electron beam. The spent beam will be verified by a 2D Tesla simulation.
The new concept of symmetric (double-folded) and asymmetric (single-folded) folded meander-line slow-wave structures is proposed for broader bandwidth and higher interaction impedance characteristics, respectively. The structures are analyzed using 3D numerical simulation in CST-Microwave Studio for the dispersion and interaction impedance characteristics at Ka- and W-bands. The results are compared...
L-3 Communications Electron Technologies (L-3 ETI) has recently tested a unit from the production family of Ku-band TWTs, the 88151HXR S/N 110, up to 200-W RF output power in thermal vacuum. Performance data and thermal analysis from the testing will be presented.
L-3 Communications Electron Technologies Inc., (L-3 ETI), continues to push the envelope for spacedownlink qualified mm-wave helix TWTs. We report results of high-power, wide bandwidth, and extreme environmental margin testing on the mm-wave family of helix TWTs from 22 GHz to 75 GHz.
A gyrotron operating at the second cyclotron harmonic in a magnetic field of 9.7 T has produced a CW output power of 25 W at 527 GHz. The gyrotron is now being employed in Dynamic Nuclear Polarization (DNP) Applications. The gyrotron design and results of the tests are presented.
Microfabricated sheet-beam traveling-wave tubes for THz and sub-THz operation have attracted a considerable interest. In this paper we discuss design issues of a double-vane slow-wave structure (SWS) for a 0.2 THz amplifier. A fast and accurate code for calculation of electrodynamic characteristics of the SWS is developed.
A 220 GHz power amplifier has been demonstrated as part of the DARPA HiFIVE program. This amplifier is based on a folded waveguide circuit, and operates at 19 kV and 250 mA. Short pulse tests resulted in 56 W at 214 GHz and a 5.0 GHz bandwidth.
Fabrication of carbon nanotube cold cathode requires an efficient and low cost process. In the paper, carbon nanotube is direct synthesized on stainless steel which acts as cathode substrate and catalyst for growing carbon nanotube. The best type of stainless steel is chosen and investigated its effect on the synthesis quality of carbon nanotube. The field emission character of carbon nanotube on...
The design and simulation of a predistortion type lineariser based on schottky diodes are proposed. With increase of input power, different combinations of the gain expansion and phase shift can be achieved over input power dynamic range. Because of this feature, it can compensate both AM-AM and AM-PM distortions for different travelling wave tube amplifiers (TWTAs) significantly. Also, it does not...
A broadband pill-box window with sapphire piece for 0.14THz folded waveguide traveling wave tube is manufactured. Cold-test result shows the attenuation of the window is about 0.7dB during 0.13THz-0.15THz. Using the back-to-back method, the RF coupling system including pill-box and taper waveguide is test. The result shows that the VSWR is less than 1.2, which meets the practical requirements in 0...
ITER is an international project supported by seven partners: China, Europe, India, Japan, Korea, Russian Federation and USA. Formally established in 2006, construction has started in France, more precisely in Provence. General progress of the project is presented followed by a focus on the RF systems which will provide 40 MW into the plasma, based on systems around 50 MHz and 170 GHz. These systems...
A square cross section ring-bar slow-wave structure with straight-edge connections has been simulated with a cylindrical electron beam for application in a traveling-wave tube amplifier. An electric field probe has been designed for coupling between the square ring-bar and a WR-10 rectangular waveguide. The saturated output peak power varies from 9.1 W to 28.6 W over the frequency range of 90–98 GHz...
One-dimensional (SUNRAY-1D), and two and half dimensional (SUNRAY-2.5D) codes are developed for accurate, fast and reliable multi-signal large signal analysis of a complete helix-type space TWT. Detailed beam and rf field parameters including inter-modulation components and higher-order time harmonics are simulated accurately for a high efficiency space TWT. The spent electron beam data of SUNRAY-2...
A three-dimensional (3-D) large signal model of beam-wave interaction in a folded waveguide (FW) slow wave circuit is described. The 3-D code carries out with numerical solutions of the structure, without using the analytical formulations of the eigenmodes. This model can also be used in helix TWTs and coupled-cavity TWTs.
We have successfully developed the vacuum-sealed carbon nano-tube (CNT) x-ray tube. The remarkable improvement of field emission properties, life time and stability, was obtained after high temperature brazing process in a vacuum circumstance.
Beam Optics Analyzer (BOA) has the capability to design all components of an electron beam from its emitter, magnetic focusing system, to the resonant cavities and the collector. We will present the current status and advances toward the goal of making BOA a multiphysics modeling and simulation tool.
A novel slow-wave-structure (SWS) named angular log-periodic micro-strip meander-line was proposed in this paper. This kind of slow wave structure is mainly determined by 3 parameters only, and the calculation results show that it has a very weakly dispersion s. That is to say, its operation bandwidth would be very wide. Its another advantage is the low operation voltage. The radial normalized phase...
Diversified Technologies, Inc. (DTI), under contract for BAE Systems, developed a switch tube test set for the realistic testing and conditioning of high power modulator switch tubes employed in radar transmitters. The system may be configured for triode or tetrode tubes and has a nominal plate power rating of 30 kW.
A novel three-dimensional finite-element (FE) modeling technique without matching meshes for the eigenmode analysis of arbitrary lossy slow-wave structures (SWSs) of traveling-wave tubes (TWTs) is presented. By simulating many examples, it is shown that the cold parameters of SWSs can be accurately and quickly obtained without matching meshes when using this technique. This technique would make the...
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