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991.
Wideband high dynamic range CMOS variable gain amplifier for low voltage and low power wireless applications 总被引:4,自引:0,他引:4
A high frequency CMOS variable gain amplifier (VGA) employing a new gain stage cell is proposed. A design technique based on the proposed VGA enables enhancement of its operating frequency up to about 350 MHz with a gain control range of 84 dB. The power consumption of the VGA implemented using a 0.18 /spl mu/m CMOS standard process is about 3 mA at 1.8 V supply voltage. 相似文献
992.
993.
Bong-Hwan Kwon Myung-Joong Youn 《Automatic Control, IEEE Transactions on》1986,31(6):591-591
Results presented by Moil in the paper, which give some bounds for the trace and the determinant of the positive definite solution to the algebraic Riccati matrix equation, are shown to be erroneous, and suggestions to remedy these errors are made. 相似文献
994.
The synthesis of various compounds containing the 1,3-benzodithiole residue is reported. The compounds are examined for application as functional dyes for carbonless duplicating systems and are found to develop slowly on silica gel, and to have good fastness to light. Especially useful was 1,1-bis(p-dimethylaminophenyl)-2-(1',3'-benzodithiol-2'-yl)ethylene (5), which developed blue on silica gel; the developing rate and fastness properties of this derivative are compared with those of benzoyl leuco Methylene Blue. 相似文献
995.
The synthesis of the protamines, the predominant nuclear proteins of mammalian spermatozoa, is regulated during germ cell development by mRNA storage for about 7 days in the cytoplasm of differentiating spermatids. Two highly conserved sequences, the Y and H elements present in the 3' untranslated regions (UTRs) of all known mammalian protamine mRNAs, form RNA-protein complexes and specifically bind a protein of 18 kDa. Here, we show that translation of fusion mRNAs was markedly repressed in reticulocyte lysates supplemented with a mouse testis extract enriched for the 18-kDa protein when the mRNAs contained the 3' UTR of mouse protamine 2 (mP2) or the Y and H elements of mP2. No significant decrease was seen when the fusion mRNAs contained the 3' UTR of human growth hormone. The 18-kDa protein is developmentally regulated in male germ cells, requires phosphorylation for RNA binding, and is found in the ribonucleoprotein particle fractions of a testicular postmitochondrial supernatant. We propose that a phosphorylated 18-kDa protein plays a primary role in repressing translation of mP2 mRNA by interaction with the highly conserved Y and H elements. At a later stage of male gamete differentiation, the 18-kDa protein no longer binds to the mRNA, likely as a result of dephosphorylation, enabling the protamine mRNA to be translated. 相似文献
996.
Gab Seon Rho Kyeong-hoon Koo Naehyuck Chang Jaehyun Park Yeong-gi Kim Wook Hyun Kwon 《Microprocessors and Microsystems》1995,19(10):599-608
A special purpose RISC (reduced instruction set computer) microprocessor for programmable logic controllers (PLC), named PLCRISC, is proposed. To develop an optimal PLCRISC, we analysed existing PLC programs currently used in factories, with special attention to the instruction execution characteristics and features required for a high performance PLC processor. Based on this analysis, an optimal RISC-style instruction set and an architecture suitable for the required features are suggested. In particular, the instruction format, the instruction pipeline, and the detailed internal architecture are the significant characteristics of the proposed PLCRISC. The performance enhancement achieved with a PLCRISC is seen from a straightforward evaluation. ASIC implementation with VHDL is also discussed. The PLCRISC is under fabrication in a 0.8 μm CMOS technology. 相似文献
997.
Removal of hot spot speckle on rear projection screen using the rotating screen system 总被引:1,自引:0,他引:1
Sung Chul Shin Sin Sung Yoo Sang Yeon Lee Chan-Young Park So-Yeon Park Jae Wook Kwon Seung-Gyu Lee 《Display Technology, Journal of》2006,2(1):79-84
This paper investigates a method to remove hot spot speckle, which is produced by laser-long coherence, on a projection screen. The objective of the work has been to first create an image from a digital light processing (DLP) display system using an RGB laser source. We then successfully obtained a high-quality image with speckle contrast, which is less than 2% when the screen was rotated by piezoelectric motor. 相似文献
998.
The LQG/LTR (linear quadratic Gaussian/loop transfer recovery) method is discussed, along with related frequency-domain properties for linear systems with delay in state. Based on the frequency-domain inequality and a robust stability condition, the guaranteed stability margin of LQ regulators and the guaranteed nondivergence margin of Kalman filters are obtained. To improve the robustness of LQG regulators, the asymptotic property of the filter gain is investigated and a loop-transfer recovery procedure is suggested with an illustration 相似文献
999.
The diffusion of zinc into GaAs, Al0.3Ga0.7As and Al0.3Ga0.7As/GaAs single heterostructures have been studied. The depth of the diffusion front is found to be proportional to the square
root of the diffusion time, [t]1/2, and for single heterostructures the Al0.3Ga0.7As layer thickness,d
1 modifies this relationship through decreasing the junction depth byd
1 multiplied by a constant. It is shown that this relationship can be used for predicting diffusion fronts in double heterostructures. 相似文献
1000.