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Efficient characterization and modelling techniques have a key role in the development of Schottky diode-based devices with state-of-the-art performance. This paper makes an effort to introduce such techniques and to provide examples of how they are used by the Schottky community. The modelling techniques covered in the paper are circuit simulator and electro-magnetic modelling. Characterization methods...
An uncertainty calculation method for the D-band power meter calibration factor is reported. In this method, the propagation of uncertainty from type-B uncertainty components is calculated using the Monte Carlo method. Then, the combined standard uncertainty is calculated as the square root sum of the uncertainty propagation and waveguide flange connection repeatability.
This paper presents a tentative modelling of Superconductor-Insulator-Superconductor (SIS) junction used as frequency multiplier. The model is tested against the experimental data presented earlier and demonstrates good agreement between the measured data and simulation. Such a model will improve understanding of the SIS junction used as frequency multiplier and hopefully lead us to demonstration...
The main objective of this paper is to present full-wave computational procedures and explicit equations leading to reproduce the experimental behavior of photoconductive antennas (PCAs) in the frame of time-domain spectroscopy systems. Additionally, the computational tools developed are aimed to analyze the efficiency of such antennas.
A new technique for the analysis and attenuation calculation of sub-millimeter waveguides is proposed in this paper by dividing the domain into several slices, in which the propagation constant ß and impedance Z for each slice were calculated and then used to estimate the overall attenuation as well as the reflection and transmission coefficients. Variations of losses with the waveguide dimensions,...
This study is aimed at development of a moderate power sheet-beam traveling wave tube (TWT) amplifier with grating slow-wave structure (SWS). A fast and accurate code for calculation of eigenwaves in the grating SWS is developed, and results of numerical modeling of a G-band TWT are presented. Electron gun producing an intensive sheet electron beam is developed. Beam focusing and transportation is...
The new gyrotron simulation code TWANG-PIC, a Particle-In-Cell (PIC)-version of the code will be presented, which solves the slow-timescale self-consistent wave-particle interaction equations for a single transverse mode. This code represents a considerable improvement with respect to the previous trajectory-code by relaxing the approximation of a time-frozen electromagnetic (EM)-field during the...
A new method for modeling terahertz photoconductive antennas (THz-PCAs) is presented. The finite element method solver COMSOL® is utilized to combine Maxwell's, Poisson's and the Drift-Diffusion equations into a single 2D/3D multiphysics model. This model can then be used to computationally investigate and design THz-PCAs with more complex geometries compared with current numerical methods. Preliminary...
We have analyzed the effects of LO phase noise on submillimeter-wave (submm) spectrometers. The phase error integrated from half the spectrometer bandwidth must be < 45 degrees to not distort the spectrometer response. For a phase noise spectrum with f−3 rolloff, the noise level at 1 MHz offset must be < −96 dBc for a 100 kHz spectrometer channel width.
Terahertz metamaterial technique enables a sophisticated electromagnetic excitation of materials. Here, we demonstrate resonant excitation of spin precession motion of canted antiferromagnet ErFeO3 using the magnetic near-field produced by split ring resonator (SRR). When the resonance frequency of spin precession was near the magnetic resonance mode of SRR, we observed substantial increase of precession...
A THz TDS study of permittivity and conductivity properties of new variant of Yttria-stabilized-Zirconia (YSZ) produced using tape-cast method is reported. This study extends the frequency coverage of some of the previously published work. We find a general agreement with published results but the frequency gap in the mm-wave range needs to be measured more carefully before final conclusions on the...
Terahertz radiation is used to follow the solid state reaction to form cocrystals of theobromine and oxalic acid. The formation of an intermediate state is observed, and the cocrystal formation kinetics display a different reaction profile to the loss of the intermediate, thus supporting a moisture mediated reaction mechanism. We propose that THz-TDS is a useful tool in understanding such reactions,...
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