Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "enhancement mode" wg kryterium: Wszystkie pola


Wyświetlanie 1-6 z 6
Tytuł:
High Quality Gate Insulator/GaN Interface for Enhancement-Mode Field Effect Transistor
Autorzy:
Taube, A.
Kruszka, R.
Borysiewicz, M.
Gierałtowska, S.
Kamińska, E.
Piotrowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1492515.pdf
Data publikacji:
2011-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
77.55.dj
77.22.Ch
73.40.Qv
81.15.Gh
81.15.Cd
Opis:
The capacitance-voltage measurements were applied for characterization of the semiconductor/dielectric interface of GaN MOS capacitors with $SiO_2$ and $HfO_2//SiO_2$ gate stacks. From the Terman method low density of interface traps $(D_{it} \approx 10^{11} eV^{-1} cm^{-2})$ at $SiO_2//GaN$ interface was calculated for as-deposited samples. Samples with $HfO_2//SiO_2$ gate stacks have higher density of interface traps as well as higher density of mobile charge and effective charge in the dielectric layers. High quality of $SiO_2//GaN$ interface shows applicability of $SiO_2$ as a gate dielectric in GaN MOSFET transistors.
Źródło:
Acta Physica Polonica A; 2011, 120, 6A; A-022-A-024
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania ewaluacyjne tranzystora 650 V E-HEMT GaN do zastosowań w wysokosprawnych przekształtnikach DC/DC
Evaluation of a 650 V E-HEMT GaN transistor for high-efficiency DC/DC converters
Autorzy:
Czyż, P.
Cichowski, A.
Śleszyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/269112.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
azotek galu
GaN
E-HEMT
przekształtnik obniżający
napięcie
straty mocy
gallium nitride
enhancement mode
high electron mobility transistor E-HEMT
DC/DC converters
power losses
Opis:
Tematem artykułu są badania wysokonapięciowego tranzystora z azotku galu typu E-HEMT w aplikacji przekształtnika obniżającego napięcie typu buck. W pracy przedstawiono krótką charakterystykę i zalety półprzewodników szerokoprzerwowych, a także opis tranzystora GS66508P-E03 w obudowie do montażu powierzchniowego (SMD). Następnie poruszono problem chłodzenia łącznika mocy SMD i przeprowadzono badanie porównawcze dwóch układów chłodzenia. Wykazano, że zaproponowany układ jest ponad dwa razy bardziej wydajny niż zalecany przez producenta. W głównej części opracowania zaprezentowano wyniki pomiarów sprawności przekształtnika. Osiągnięto sprawność > 92 % dla układu twardo przełączającego o częstotliwości pracy 200 kHz. Tym samym potwierdzono możliwość budowania wysokosprawnych przekształtników z tranzystorami GaN.
In this paper a brief description of wide-bandgap semiconductors is given. Particularly, advantages of a 650 V GaN EHEMT transistor GS66508P-E03 are shown. This power switch is experimentally evaluated in a synchronous buck with two transistors in a half bridge configuration. The experimental results show that GaN transistors have very low total losses even when operating at high frequencies. The efficiency over 92% is achieved at the frequency of 200 kHz with 5 A output current and output power at a rate of 310 W. Additionally, in this work two different cooling systems for surface mounted transistor are compared. In a prototype for thermal evaluation one transistor has the cooling system with thermal vias through the PCB and alternatively the second one has the cooling system with the copper stud. The proposed cooling system with the copper stud is proven to have the twice smaller thermal resistance than the system with thermal vias. Another advantage is that in the same conditions the transistor is cooler and has lower on-resistance, what decreases the power losses.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2015, 47; 31-34
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bandwidth Enhancement for Half Mode Substrate Integrated Waveguide Antenna using Defected Ground Structures
Autorzy:
Astuti, Dian Widi
Rivayanto
Muslim
Simanjuntak, Imelda
Firmansyah, Teguh
Cahyasiwi, Dwi Astuti
Natali, Yus
Powiązania:
https://bibliotekanauki.pl/articles/27311970.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Bandwidth enhancement
dual cavity
half modesubstrate integrated waveguide
defected ground structure
U-slot
Opis:
The SIW antenna suffers from the narrow bandwidth for a single cavity and single resonant. Defected ground structure (DGS) with a dual cavity was the solution to solve narrow bandwidth by resulting in hybrid resonance. The hybrid resonance with 14.83% impedance bandwidth is proposed in this antenna design. The first resonance resulted from the combination of the TE101 modes from inner and outer HMSIW cavities while the second resonance resulted from the combination of the strong TE101 and the weak TE102 mode from the inner HMSIW cavity and the addition of the weak TE101 from the outer HMSIW cavity. The measurement antenna design has a broadband antenna with a 14.31% (5.71 – 6.59 GHz) impedance bandwidth by using substrate Rogers RO 5880.
Źródło:
International Journal of Electronics and Telecommunications; 2023, 69, 3; 449--454
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speech Enhancement Using Sliding Window Empirical Mode Decomposition and Hurst-based Technique
Autorzy:
Poovarasan, Selvaraj
Chandra, Eswaran
Powiązania:
https://bibliotekanauki.pl/articles/176311.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
speech enhancement
Empirical Mode Decomposition
EMD
Intrinsic Mode Functions
hurst exponent
Sliding Window
SW
Opis:
The most challenging in speech enhancement technique is tracking non-stationary noises for long speech segments and low Signal-to-Noise Ratio (SNR). Different speech enhancement techniques have been proposed but, those techniques were inaccurate in tracking highly non-stationary noises. As a result, Empirical Mode Decomposition and Hurst-based (EMDH) approach is proposed to enhance the signals corrupted by non-stationary acoustic noises. Hurst exponent statistics was adopted for identifying and selecting the set of Intrinsic Mode Functions (IMF) that are most affected by the noise components. Moreover, the speech signal was reconstructed by considering the least corrupted IMF. Though it increases SNR, the time and resource consumption were high. Also, it requires a significant improvement under nonstationary noise scenario. Hence, in this article, EMDH approach is enhanced by using Sliding Window (SW) technique. In this SWEMDH approach, the computation of EMD is performed based on the small and sliding window along with the time axis. The sliding window depends on the signal frequency band. The possible discontinuities in IMF between windows are prevented by the total number of modes and the number of sifting iterations that should be set a priori. For each module, the number of lifting iterations is determined by decomposition of many signal windows by standard algorithm and calculating the average number of sifting steps for each module. Based on this approach, the time complexity is reduced significantly with suitable quality of decomposition. Finally, the experimental results show the considerable improvements in speech enhancement under non-stationary noise environments.
Źródło:
Archives of Acoustics; 2019, 44, 3; 429-437
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Monte Carlo study on dose enhancement and photon contamination production by various nanoparticles in electron mode of a medical linac
Autorzy:
Bahreyni Toossi, M. T.
Ghorbani, M.
Sobhkhiz Sabet, L.
Akbari, F.
Mehrpouyan, M.
Powiązania:
https://bibliotekanauki.pl/articles/146518.pdf
Data publikacji:
2015
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dose enhancement
electron mode
Monte Carlo
nanoparticles
photon contamination
Opis:
The aim of this study is the evaluation of electron dose enhancement and photon contamination production by various nanoparticles in the electron mode of a medical linac. MCNPX Monte Carlo code was used for simulation of Siemens Primus linac as well as a phantom and a tumor loaded with nanoparticles. Electron dose enhancement by Au, Ag, I and Fe2O3 nanoparticles of 7, 18 and 30 mg/ml concentrations for 8, 12 and 14 MeV electrons was calculated. The increase in photon contamination due to the presence of the nanoparticles was evaluated as well. The above effects were evaluated for 500 keV and 10 keV energy cut-offs defined for electrons and photons. For 500 keV energy cut-off, there was no significant electron dose enhancement. However, for 10 keV energy cut-off, a maximum electron dose enhancement factor of 1.08 was observed for 30 mg/ml of gold nanoparticles with 8 MeV electrons. An increase in photon contamination due to nanoparticles was also observed which existed mainly inside the tumor. A maximum photon dose increase factor of 1.07 was observed inside the tumor with Au nanoparticles. Nanoparticles can be used for the enhancement of electron dose in the electron mode of a linac. Lower energy electron beams, and nanoparticles with higher atomic number, can be of greater benefi t in this field. Photons originating from nanoparticles will increase the photon dose inside the tumor, and will be an additional advantage of the use of nanoparticles in radiotherapy with electron beams.
Źródło:
Nukleonika; 2015, 60, No. 3, part 1; 489-496
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Normal Mode Solutions of Target Strengths of Solid-filled Spherical Shells and Discussion of Influence Parameters
Autorzy:
Jia, Bing
Fan, Jun
Li, Gui-Juan
Wang, Bin
Chen, Yun-Fei
Powiązania:
https://bibliotekanauki.pl/articles/31339751.pdf
Data publikacji:
2024
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
solid-filled spherical shell
room temperature vulcanized silicone rubber
target strength enhancement
Opis:
The normal mode solution for the form function and target strength (TS) of a solid-filled spherical shell is derived. The calculation results of the spherical shell’s acoustic TS are in good agreement with the results of the finite element method (FEM). Based on these normal mode solutions, the influences of parameters such as the material, radius, and thickness of the inner and outer shells on the TS of a solid-filled spherical shell are analyzed. An underwater spherical shell scatterer is designed, which uses room temperature vulcanized (RTV) silicone rubber as a solid filling material and does not contain a suspension structure inside. The scatterer has a good TS enhancement effect.
Źródło:
Archives of Acoustics; 2024, 49, 1; 83-93
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies