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A 340GHz backward wave oscillator (BWO) based on the sine waveguide and pencil electron beam is presented as a novel terahertz radiation source. The particle-in-cell (PIC) simulation results predicts that this device can produce the output power of over 2.7W in the frequency range of 335.8–348.5GHz by utilizing a 20mA pencil beam and adjusting the voltage from 12kV to 14 kV.
In this paper, a novel and small sub-terahertz (THz) sheet beam extended interaction klystron (EIK) has been designed. With the help of a three-dimensional(3D) particle-in-cell(PIC) simulation, design and optimizing geometry of THz sheet beam EIK is performed. The interaction system consists of two dumbbell five-gap cavities, one is used for input cavity, the other is output cavity. The operating...
A multi-megawatt Electron Cyclotron Resonance Heating (ECRH) system is in routine operation at the ASDEX Upgrade (AUG) tokamak. It applies four step-tunable gyrotrons at 105 and 140 GHz with 10 s pulse length and output powers close to 1 MW. An upgrade with four more gyrotrons is underway which will double the installed power. The first two-frequency gyrotron of the new series has recently been installed...
Research activity on development of gyrotron travelling-wave tubes (gyro-TWTs) at the Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS) is presented. In the gyro-TWTs under discussion a helically corrugated waveguide is used as a principal part of their microwave circuits which ensures a number of advantages over other configurations of the gyro-TWTs.
The output power and tuning range of injection-seeded terahertz-wave parametric generators (is-TPG) have improved significantly in recent years. Peak output power of a few tens of kW have been achieved, and the upper limit of the tuning range has increased from 3.0 to 5.0 THz. However, the acquisition of spectra requires long measurement time, because is-TPG is a tunable source and emits only one...
In this paper, a two-section folded waveguide (TSFW) structure for generating prebunching beam in terahertz (THz) extended interaction oscillator (EIO) is presented and demonstrated. For the realized aim of prebunching beam in the TSFW, it is split into two halves. With help of high speed numerical mill, the TSFW is manufactured. To avoid the effects of size deformation on the interaction of beam-wave...
Quad-frequency oscillation from 100 GHz to 200 GHz was demonstrated using ITER gyrotron at QST. Those RF beam passed through the center of the gyrotron window and good couples to transmission line were obtained for each oscillation. The mega-watt-class power was obtained for all frequencies. Validation of gyrotron for a demo reactor is numerically started on the basis of our multi-frequency gyrotron.
An H-Band ×4 frequency multiplier chain implemented in an advanced 90 nm SiGe BiCMOS technology is presented. The chain achieves a peak output power of 4 dBm and consists of D-Band doubler followed by D-Band power amplifier which drives an H-Band doubler. It operates from 202 GHz to 247 GHz (3 dB power bandwidth) with 2 dBm input power at V-Band and consumes a total DC power of 250 mW. This paper...
We proposed and fabricated a novel resonant-tunneling-diode terahertz oscillator integrated with dipole array antennas coupled with a slot resonator to obtain output power with multiple peaks, which is convenient for imaging without interference fringes caused by coherence. We measured the radiation pattern for single and arrayed oscillators, and calculated the output power using the integration of...
An ultra-wide band W-Band travelling wave tube using staggered double vane slow wave structure (SDV-SWS) combined with plan alignment three pencil beams is investigated in this paper. Instead of only using the fundamental mode, the first two modes of SDV-SWS are designed to match with the same electron beam to promote the bandwidth. Particle in cell (PIC) simulations with our new type of two stages...
The components of a W-band gyro-TWA including input coupler, output window, corrugated output mode converter, pulsed power system and water-cooled beam dump are being upgraded to achieve an output power of 5 kW and a high pulse repetition rate of 2 kHz for cloud radar applications. Latest results of the W-band gyro-TWA with a helically corrugated waveguide and a cusp electron gun are presented.
A compact 272–288 GHz transmitter with integrated VCO is presented. This source is suitable for use in compact radar, imaging, and spectroscopy systems as an alternative to a W-band Gunn oscillator cascaded with W-band power amplifier and frequency multiplier. The transmitter has a x36 multiplication factor and has external dimensions of 0.875″ × 1.0″ × 1.25″. Measured output power is greater than...
In this paper, we propose a new architecture of photomixer in order to develop a wideband and powerful photomixing THz source. It is achieved by a velocity-matched distributed photoconductor, in which the pump optical power is guided in a dielectric optical guide and slightly coupled to a low-temperature grown GaAs 1-mm-length photoconductor.
In this work we report on the design, fabrication and initial tests of an ultra-compact 16-pixel 1.9 THz local oscillator source with >10 μW output power per pixel at room temperature. The power of each pixel can be individually controlled through the dc bias of the multiplier stages. The total dimensions of the module is 143mm × 30 mm × 25 mm. The pixel spacing is 5 mm and the total estimated...
We present ultra-broadband room temperature monolithic terahertz quantum cascade laser (QCL) sources based on intra-cavity difference frequency generation, emitting continuously more than one octave in frequency between 1.6 and 3.8 THz, with a peak output power of ∼0.2 mW. Broadband terahertz emission is realized by nonlinear mixing between single mode and multi mode spectra due to distributed feedback...
The results of stabilization of both output power and frequency by double PID feedback control of the acceleration and anode voltage in the 460 GHz Gyrotron FU CW GVI (“Gyrotron FU CW GO-1” as an official name in Osaka University) are presented. The experiment based on the cyclotron frequency modulation by modulation of acceleration voltage of beam electrons and on pitch factor modulation by modulation...
Powerful high-efficiency FEM-amplifier operating over Ka frequency range and aimed on accelerating applications is developed in collaboration between IAP RAS and JINR. To achieve a broad amplification band in a regular wiggler, we utilized the so-called grazing regime, in which about of 20 MW of output power was simulated in the frequency range of 30 ± 3 GHz. In the first stage of experiments, the...
A THz laser source based on stimulated polariton scattering (SPS) in an intracavity RbTiOPO4 (RTP) crystal is reported, with frequency-tunable output from 3.10 to 3.16 THz and from 3.50 to 4.15 THz. The gap exhibited from 3.17 to 3.49 THz is located in the vicinity of the 104 cm−1 absorbing mode in RTP. A maximum average output power of 16.2 μW was measured at 3.80 THz.
The LOCUS atmospheric sounder is a satellite-borne THz radiometer concept, for studying molecular species in the mesosphere and lower thermosphere. We report waveguide-integrated THz quantum-cascade lasers for use as 3.5 THz local oscillators. A waveguide-integration scheme, using an integrated diagonal feedhorn significantly improves power outcoupling. 1.3 mW THz emission is demonstrated in a space-qualified...
For utilization of the real THz applications by semiconductor base QCLs, the performances balance of their output power and operation temperature are required for the recent devices. Here we demonstrate our fabricated THz QCLs toward high output power with liquid nitrogen Dewar condenser to approach the target of mW order average output power relative compact size portable THz source unit.
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