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排序方式: 共有796条查询结果,搜索用时 31 毫秒
1.
This article presents a design methodology for linearizing GaN HEMT amplifiers based on splitting a large FET into multiple parallel FETs with same total gate periphery and by biasing them individually. By varying the biases, the magnitude and the phase of the IMD3 components at the output of FET changes. A detailed simulation methodology using commercial microwave CAD software is presented. Simulation results show that by biasing one device in Class AB and other(s) in deep Class AB mode, IMD3 components of parallel FETs can be made out of phase to each other leading to cancellation and improvement in linearity. Three prototype circuits were simulated using (a) a single 5 mm FET (1 × 5 mm), (b) two parallel 2.5 mm FETs (2 × 2.5 mm), and (c) four parallel 1.25 mm FETs (4 × 1.25 mm), for a total gate periphery of 5 mm, over the frequency range of 0.8 to 1.0 GHz. IMD3 improvement up to 20 dBc was achieved with the 4 × 1.25 mm circuit when the FET biases were optimized. Measurement results show improvement in linearity up to 20 dBc for 4 × 1.25 mm circuit. The proposed method improves linearity without a substantial penalty on the power consumption and is straightforward to implement. 相似文献
2.
In this research work, we have characterized and simulated a well-known hole transport material (HTM) for perovskite solar cell (PSC) and conductive polyme 相似文献
3.
4.
Journal of Materials Science - Flexible and stretchable strain sensors are in great demand in advanced health care, human–machine interface, stretchable electronics, electronic skin, etc. Of... 相似文献
5.
Precipitation of phosphate minerals from liquid swine manure is an established means of reducing the orthophosphate (OP) concentration. This project investigated the usefulness of a chemical equilibrium model, Visual Minteq, for prescribing the amendments needed to maximize struvite precipitation from liquid swine manure and thus reduce the OP phosphorus concentration. The actual concentrations of Mg(2+), Ca(2+), K(+), OP, NH(4)(+), alkalinity and pH from a liquid swine manure system were used as inputs to the model. The model was modified to remove species with extremely low formation rates, because they would not significantly precipitate in the reaction occurring in a short retention-time process such as those envisioned for swine manure struvite-formation reactors. Using the model's output, a series of 19-L reactors were used to verify the results. Verification results demonstrated that Visual Minteq can be used to pre-determine the concentration of amendments required to maximize struvite recovery. 相似文献
6.
Julie Chandra C. S. Bipinbal P. K. Dileep P. Sasi Sreesha Raman Vidya Bindu Sharmila T. K. Narayanankutty Sunil K. 《SILICON》2022,14(13):7919-7932
Silicon - Nanosilica was synthesized from a low cost raw material, olivine by a more sustainable and cost effective method. The pure nanosilica obtained was amorphous in nature with a surface area... 相似文献
7.
Ronald E. Davis Dallas G. Denery David A. Kendrick Raman K. Mehra 《Computational Economics》2012,39(1):71-76
A continuous-time control model was formulated and fitted to macroeconomic data by an expert control engineer who worked at
NASA-AMES in the 1980s, Rodney C. Wingrove. Two articles were prepared and made available to the aerospace industry at that
time, however the authors feel that wider distribution of his study posthumously is warranted at this time. This introduction
to the two Wingrove articles that follow provides background information on the technologies Wingrove was working with, as
well as subsequent developments in both macroeconomic and engineering modeling and analysis technology. Our purpose is to
stimulate further research along the same lines which can potentially lead to structural and/or policy rule improvements that
can prevent the extremely turbulent abberations that have been seen in recent years, and promote steady growth with low inflation
and low unemployment in a sustainable way. Of particular concern is the exploding national debt problem. 相似文献
8.
Chemical‐looping combustion — an overview and application of the recirculating fluidized bed reactor for improvement 下载免费PDF全文
This paper propose recirculating fluidized bed (RCFB) reactor for chemical‐looping combustion (CLC) to overcome some of the issues associated with the existing interconnected reactors arrangements like low residence time of bed material in the air reactor, high attrition of bed material in the cyclone separator, cluster formation in the air reactor, complex operation involving loop seals and high heat losses. RCFB has high solid circulation rate, long residence time, efficient fuel–oxygen carrier contact, low heat losses and low gas leak in between the reactors, as compared to the existing reactor configurations. A cold model study was performed on a Perspex made, semicircular, transparent RCFB reactor. A single RCFB reactor was operated in the alternate oxidation and fuel burning cycles to simulate the interconnected reactors arrangement for CLC. The generated experimental data has been used to predict the optimal RCFB reactor configuration for a RCFB‐based CLC power plant. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
9.
Raman K. Mishra Vasanthakumaran Sudarsan Savita Jain Chetan P. Kaushik Rajesh K. Vatsa Avesh K. Tyagi 《Journal of the American Ceramic Society》2014,97(2):427-431
Barium sodium borosilicate glasses containing different amounts of uranium oxides were prepared by conventional melt quench method and investigated for their structural aspects by 29Si and 11B MAS NMR technique combined with steady‐state luminescence and lifetime measurements. Based on MAS NMR studies, it is confirmed that uranium ions act as network modifier up to 15 wt% and beyond which a separate uranium containing phase is formed. From the luminescence studies, it is inferred that uranyl species is in a highly distorted environment. For more than 15 wt% uranium oxide incorporation, weaker U–O–U linkages are formed at the expense stronger U–O–Si/B linkages, as suggested by the excited state lifetime value of the uranyl species as well as red shift in emission peak maximum. For glass samples containing more than 25 wt% uranium oxides, crystalline barium uranium silicate gets phase separated from glass matrix as confirmed by XRD studies. 相似文献
10.
Dhineshbabu Nattanmai Raman Karunakaran Gopalu Suriyaprabha Rangaraj Manivasakan Palanisamy Rajendran Venkatachalam 《纳微快报(英文)》2014,6(1):46-54
Nano-Micro Letters - Magnesia (MgO) nanoparticles were produced from magnesite ore (MgCO3) using ball mill. The crystalline size, morphology and specific SSA were characterized by X-ray diffraction... 相似文献