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101.
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103.
Optimization of EDGE terminal power amplifiers using memoryless digital predistortion 总被引:1,自引:0,他引:1
This paper describes a lookup-table (LUT)-based digital predistortion system usable for enhanced data for global system for mobile evolution (EDGE) handset transmitters. The system is memoryless and capable of improving average efficiency and performance in terms of the leakage power at offset frequencies and error vector magnitude. The obtainable efficiency at maximum linear output power is comparable, but at backoffs superior to commercial EDGE power amplifiers (PAs). Minimum system requirements on word length and LUT size have been investigated, which shows that a LUT having approximately 500 coefficients and a system word length of 13 bits are sufficient for EDGE. The proposed system is simple compared to basestation implementations comprising PA memory compensation and can be easily implemented in handsets in order to improve the overall system performance. The effects of antenna mismatch on system performance have been investigated 相似文献
104.
A. M. Stefanini Jincheng Xu L. Corradi G. Montagnoli H. Moreno Y. Nagashima L. Mueller M. Narayanasamy D. R. Napoli P. Spolaore S. Beghini F. Scarlassara G. F. Segato F. Soramel C. Signorini H. Esbensen S. Landowne G. Pollarolo 《Physics letters. [Part B]》1990,240(3-4):306-310
Elastic scattering angular distributions have been measured for 58Ni+64Ni at three energies around the Coulomb barrier employing a new kinematic coincidence technique. The data are compared with the results of coupled-channels calculations including inelastic excitations as well as one-and two-neutron transfer reactions. The agreement is good and the calculations also agree well with the available transfer and fusion reaction data. 相似文献
105.
Tavorite‐structured oxyphosphates, fluorophosphates, oxysulfates, and fluorosulfates are evaluated for use as cathode materials in lithium ion batteries and activation energies for lithium diffusion through LiVO(PO4), LiV(PO4)F, and LiFe(SO4)F are calculated. 相似文献
106.
William J. Evans Prof. Thomas J. Mueller Joseph W. Ziller Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(3):964-975
The limits of steric crowding in organometallic metallocene complexes have been examined by studying the synthesis of [(C5Me5)3MLn] complexes as a function of metal in which L=Me3CCN, Me3CNC, and Me3SiCN. The bis(tert‐butyl nitrile) complexes [(C5Me5)3Ln(NCCMe3)2] (Ln=La, 1 ; Ce, 2 ; Pr, 3 ) can be isolated with the largest lanthanide metal ions, La3+, Ce3+, and Pr3+. The Pr3+ ion also forms an isolable mono‐nitrile complex, [(C5Me5)3Pr(NCCMe3)] ( 4 ), whereas for Nd3+ only the mono‐adduct [(C5Me5)3Nd(NCCMe3)] ( 5 ) was observed. With smaller metal ions, Sm3+ and Y3+, insertion of Me3CCN into the M? C(C5Me5) bond was observed to form the cyclopentadiene‐substituted ketimide complexes [(C5Me5)2Ln{NC(C5Me5)(CMe3)}(NCCMe3)] (Ln=Sm, 6 ; Y, 7 ). With tert‐butyl isocyanide ligands, a bis‐isocyanide product can be isolated with lanthanum, [(C5Me5)3La(CNCMe3)2] ( 8 ), and a mono‐isocyanide product with neodymium, [(C5Me5)3Nd(CNCMe3)] ( 9 ). Silicon–carbon bond cleavage was observed in reactions between [(C5Me5)3Ln] complexes and trimethylsilyl cyanide, Me3SiCN, to produce the trimeric cyanide complexes [{(C5Me5)2Ln(μ‐CN)(NCSiMe3)}3] (Ln=La, 10 ; Pr, 11 ). With uranium, a mono‐nitrile reaction product, [(C5Me5)3U(NCCMe3)] ( 12 ), which is analogous to 5 , was obtained from the reaction between [(C5Me5)3U] and Me3CCN, but [(C5Me5)3U] reacts with Me3CNC through C? N bond cleavage to form a trimeric cyanide complex, [{(C5Me5)2U(μ‐CN)(CNCMe3)}3] ( 13 ). 相似文献
107.
Kohley Z Liang JF Shapira D Varner RL Gross CJ Allmond JM Caraley AL Coello EA Favela F Lagergren K Mueller PE 《Physical review letters》2011,107(20):202701
The fusion excitation functions for radioactive (132)Sn + (58)Ni and stable (130)Te + (58,64)Ni were measured at energies near the Coulomb barrier. The coupling of transfer channels in heavy-ion fusion was examined through a comparison of Sn + Ni and Te + Ni systems, which have large variations in the number of positive Q-value nucleon transfer channels. In contrast with previous experimental comparisons, where increased sub-barrier fusion cross sections were observed in systems with positive Q-value neutron transfer channels, the reduced excitation functions were equivalent for the different Sn + Ni and Te + Ni systems. The present results suggest a dramatically different influence of positive Q-value transfer channels on the fusion process for the Sn + Ni and Te + Ni systems. 相似文献
108.
109.
We study lattice models of charged particles in uniform magnetic fields. We show how longer range hopping can be engineered to produce a massively degenerate manifold of single-particle ground states with wave functions identical to those making up the lowest Landau level of continuum electrons in a magnetic field. We find that in the presence of local interactions, and at the appropriate filling factors, Laughlin's fractional quantum Hall wave function is an exact many-body ground state of our lattice model. The hopping matrix elements in our model fall off as a Gaussian, and when the flux per plaquette is small compared to the fundamental flux quantum one only needs to include nearest and next-nearest neighbor hoppings. We suggest how to realize this model using atoms in optical lattices, and describe observable consequences of the resulting fractional quantum Hall physics. 相似文献
110.