High-frequency (245 GHz) and X-band EPR study of stable dicopper radical complexes

1999 ◽  
pp. 3855-3857 ◽  
Author(s):  
Anne-Laure Barra ◽  
Louis-Claude Brunel ◽  
Frank Baumann ◽  
Manuela Schwach ◽  
Michael Moscherosch ◽  
...  
Keyword(s):  
High Frequency ◽  
X Band

High-frequency circuit simulation in X-band coupled-cavity TWT

2015 ◽  
Author(s):  
Peng Chao-Huang ◽  
Hui-Xu ◽  
Wei Ling-Qi ◽  
Tian-Liang ◽  
Da Xi-Ji
Keyword(s):  
High Frequency ◽  
Circuit Simulation ◽  
X Band ◽  
Coupled Cavity

scholarly journals Electrical performances of AlInN/GaN HEMTs. A comparison with AlGaN/GaN HEMTs with similar technological process

2011 ◽  
Vol 3 (3) ◽  
pp. 301-309 ◽  
Author(s):  
Olivier Jardel ◽  
Guillaume Callet ◽  
Jérémy Dufraisse ◽  
Michele Piazza ◽  
Nicolas Sarazin ◽  
...  
Keyword(s):  
High Frequency ◽  
Continuous Wave ◽  
High Electron Mobility Transistors ◽  
High Electron ◽  
Power Added Efficiency ◽  
Electron Mobility Transistors ◽  
X Band ◽  
Gan Hemts ◽  
Load Pull ◽  
Interesting Alternative

A study of the electrical performances of AlInN/GaN High Electron Mobility Transistors (HEMTs) on SiC substrates is presented in this paper. Four different wafers with different technological and epitaxial processes were characterized. Thanks to intensive characterizations as pulsed-IV, [S]-parameters, and load-pull measurements from S to Ku bands, it is demonstrated here that AlInN/GaN HEMTs show excellent power performances and constitute a particularly interesting alternative to AlGaN/GaN HEMTs, especially for high-frequency applications beyond the X band. The measured transistors with 250 nm gate lengths from different wafers delivered in continuous wave (cw): 10.8 W/mm with 60% associated power added efficiency (PAE) at 3,5 GHz, 6.6 W/mm with 39% associated PAE at 10.24 GHz, and 4.2 W/mm with 43% associated PAE at 18 GHz.

scholarly journals Side Effects in a HEMT Performance with InAlN/GaN

2015 ◽  
Vol 15 (2) ◽  
pp. 249
Author(s):  
Z. Kourdi ◽  
B. Bouazza ◽  
A. Guen-Bouazza ◽  
M. Khaouani
Keyword(s):  
Side Effects ◽  
Current Density ◽  
High Frequency ◽  
Density Ratio ◽  
High Electron Mobility Transistor ◽  
Maximum Efficiency ◽  
High Electron ◽  
X Band ◽  
Cutting Frequency ◽  
Gan Heterostructure

<p class="Abstract">We present a simulation of a HEMT (high electron mobility transistor) structure. We extract the device characteristics through the analysis of DC, AC and high frequency regimes, as shown in this paper. This work demonstrates the optimal device with a gate length of 30<span style="text-decoration: underline;"> nm</span>, and InAlN/GaN heterostructure for minimizing side effects. The simulated with Silvaco software of the HEMT devices with the materials InAlN show very good scalability in different application. We have demonstrated an excellent current density, as high as 644 mA/mm, a peak extrinsic transconductance of 710 mS/mm at V<sub>DS</sub>=2 <span style="text-decoration: underline;">V</span>, and cutting frequency cutoffs of 385 GHZ, maximum frequency of 810 GHz, maximum efficiency of 23% for x-Band, maximum breakdown voltage of 365 <span style="text-decoration: underline;">V</span>, and an ON/OFF current density ratio higher than 8 x 10<sup>8</sup>. These values were determined through the simulation by hydrodynamics models, which makes that optimize the design is the future of this technology.</p>

Simulation study on high frequency characteristics of X-band high power relative klystron amplifier

2014 ◽  
Vol 26 (2) ◽  
pp. 23006 ◽  
Author(s):  
朱丹妮 Zhu Danni ◽  
张军 Zhang Jun ◽  
李伟 Li Wei ◽  
戚祖敏 Qi Zumin
Keyword(s):  
Simulation Study ◽  
High Power ◽  
High Frequency ◽  
Frequency Characteristics ◽  
X Band

scholarly journals Coupling X-band dual-polarized mini-radars and hydro-meteorological forecast models: the HYDRORAD project

2013 ◽  
Vol 13 (5) ◽  
pp. 1229-1241 ◽  
Author(s):  
E. Picciotti ◽  
F. S. Marzano ◽  
E. N. Anagnostou ◽  
J. Kalogiros ◽  
Y. Fessas ◽  
...  
Keyword(s):  
Decision Support ◽  
High Frequency ◽  
Weather Radar ◽  
Decision Support Tool ◽  
Dual Polarization ◽  
Radar Observations ◽  
Support Tool ◽  
Radar Network ◽  
X Band ◽  
Modelling System

Abstract. Hydro-meteorological hazards like convective outbreaks leading to torrential rain and floods are among the most critical environmental issues world-wide. In that context weather radar observations have proven to be very useful in providing information on the spatial distribution of rainfall that can support early warning of floods. However, quantitative precipitation estimation by radar is subjected to many limitations and uncertainties. The use of dual-polarization at high frequency (i.e. X-band) has proven particularly useful for mitigating some of the limitation of operational systems, by exploiting the benefit of easiness to transport and deploy and the high spatial and temporal resolution achievable at small antenna sizes. New developments on X-band dual-polarization technology in recent years have received the interest of scientific and operational communities in these systems. New enterprises are focusing on the advancement of cost-efficient mini-radar network technology, based on high-frequency (mainly X-band) and low-power weather radar systems for weather monitoring and hydro-meteorological forecasting. Within the above context, the main objective of the HYDRORAD project was the development of an innovative \\mbox{integrated} decision support tool for weather monitoring and hydro-meteorological applications. The integrated system tool is based on a polarimetric X-band mini-radar network which is the core of the decision support tool, a novel radar products generator and a hydro-meteorological forecast modelling system that ingests mini-radar rainfall products to forecast precipitation and floods. The radar products generator includes algorithms for attenuation correction, hydrometeor classification, a vertical profile reflectivity correction, a new polarimetric rainfall estimators developed for mini-radar observations, and short-term nowcasting of convective cells. The hydro-meteorological modelling system includes the Mesoscale Model 5 (MM5) and the Army Corps of Engineers Hydrologic Engineering Center hydrologic and hydraulic modelling chain. The characteristics of this tool make it ideal to support flood monitoring and forecasting within urban environment and small-scale basins. Preliminary results, carried out during a field campaign in Moldova, showed that the mini-radar based hydro-meteorological forecasting system can constitute a suitable solution for local flood warning and civil flood protection applications.

A Tyrosyl Radical in an Irradiated Single Crystal ofN-Acetyl-l-tyrosine Studied by X-band cw-EPR, High-Frequency EPR, and ENDOR Spectroscopies

1999 ◽  
Vol 103 (48) ◽  
pp. 9636-9643 ◽  
Author(s):  
Alberto Mezzetti ◽  
Anna Lisa Maniero ◽  
Marina Brustolon ◽  
Giovanni Giacometti ◽  
Louis Claude Brunel
Keyword(s):  
Single Crystal ◽  
High Frequency ◽  
Tyrosyl Radical ◽  
X Band

scholarly journals A closed modified V-shaped uniplanar triple band ACS fed antenna for wireless applications

2020 ◽  
Vol 9 (4) ◽  
pp. 1497-1505
Author(s):  
Anuj Kumar ◽  
Anukul Jindal ◽  
Apurva Singh ◽  
Reshma Roy ◽  
Om Prakash Kumar ◽  
...  
Keyword(s):  
High Frequency ◽  
Impedance Matching ◽  
Simulation Software ◽  
Impedance Bandwidth ◽  
Wireless Applications ◽  
Feed Line ◽  
X Band ◽  
Rectangular Strips ◽  
Different Characteristics ◽  
Triple Band

In the proposed paper, a uniplanar asymmetric coplanar strip (ACS) fed antenna with closed V-shaped radiating patch of size  printed on FR4 substrate with loss tangent ( =0.02, height (h)=1.6mm, and dielectric constant of 4.4 covering WiMAX, X-band and WLAN applications is presented. The proposed closed V-shaped radiating patch is formed by joning two rectangular stubs. The resultant shape of the radiating patch is obtained by adding rectangular strips to feed line until desired multiband results are achieved.  The advantage of this structure is that it forms simple configuration as well as helps the overall antenna in attaining three distinict useful frequency band with good impedance matching for S11-10 dB criteria. The proposed ACS fed antenna operates at 3.1 (WiMAX), 5.0 (WLAN) and 9.9 (X-band) GHz with impedance bandwidth ranging from 2.7-3.9 GHz, 4.4-5.5 GHz and 9.5-10.3 GHz in simulation. Under measurement the proposed antenna shows multiband phenomenon at 3.2, 5.3 and 9.7 GHz with impedance bandwidth ranging from 2.8-3.7 GHz, 4.6-5.4 GHz and 9.4-10 GHz, respectively. The antenna exhibits simulated gain of 2.51, 1.18 and 1.96 dB at the corresponding frequency bands of 3.1, 5.0 and 9.9 GHz. The key parameters of the antenna like length and width of the multi-branched strips are optimized to get the multiband operation. The deisign simulation is carried out in Ansys HFSS (High frequency Simulation Software) where different characteristics of the proposed antenna are investigated. The evolution and optimization process is dealt in detail with the help of S11, VSWR, current distributions, radiation patterns and gain.

scholarly journals Design and Simulation of Rectangular Microstrip Double Patch Antenna for X Band

2021 ◽  
Vol 9 (10) ◽  
pp. 453-459
Author(s):  
Neha Afreen
Keyword(s):  
Radiation Pattern ◽  
Patch Antenna ◽  
High Frequency ◽  
Return Loss ◽  
Dielectric Substrate ◽  
Substrate Material ◽  
Feed Line ◽  
X Band ◽  
Microstrip Feed Line ◽  
Microstrip Feed

Abstract: In the present work an attempt has been made to design and simulation of rectangular microstrip double patch antenna for X band using microstrip feed line techniques. HFSS High frequency simulator is used to analyse the proposed antenna and simulated the result on the return loss, radiation pattern and gain of the proposed antenna. The antenna is able to achieve in the range of 8-12 GHz for return loss of less than -10 dB. The operating frequency of the proposed antenna is 8.7 GHz with dielectric substrate, ARLON of = 2.5 and h= 1.6mm. Keywords: ARLON substrate material, FEM, Microstrip Feed Line, X band

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