Institution
Philips
Company•Vantaa, Finland•
About: Philips is a company organization based out in Vantaa, Finland. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 68260 authors who have published 99663 publications receiving 1882329 citations. The organization is also known as: Koninklijke Philips Electronics N.V. & Royal Philips Electronics.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, the free electron densities of up to 1021 cm−3 and mobilities in the range 10−70 cm2 V−1s−1 can be obtained by means of an appropriate doping and/or oxygen deficit.
214 citations
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23 May 2002TL;DR: In this article, the time of the request is used to determine which chat room the person is placed in and the surrounding factors, or context, within which the person initiated the request.
Abstract: When a person requests access to a chat session, the time of the request is used to determine which chat room the person is placed. Other parameters are used to determine the surrounding factors, or context, within which the person initiated the request, such as the particular television program that the person was watching at the time of the request. By forming chat rooms based on the time of entry and the context in which the request is made, the chat rooms are likely to contain people with a common topic to discuss, such as the television news story being broadcast at that time. These time-of-entry chat rooms can also be structured to be of limited duration, obviating the overhead burden of deleting topic-specific chat rooms when the topic ceases to be of interest.
214 citations
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TL;DR: A structure-dependent exchange coupling across wedge-shaped Cu layers in fcc (100) Co/Cu/Co and bcc ( 100) Fe/ Cu/Fe epitaxial sandwiches has been determined from analysis of longitudinal magneto-optical Kerr effect hysteresis loops.
Abstract: A structure-dependent exchange coupling across wedge-shaped Cu layers in fcc (100) Co/Cu/Co and bcc (100) Fe/Cu/Fe epitaxial sandwiches has been determined from analysis of longitudinal magneto-optical Kerr effect hysteresis loops. In the fcc Co/Cu/Co system, the variation of the coupling with Cu thickness can be described as a superposition of two oscillatory terms, with periods of 2.6 and 8.0 monolayers (ML). The bcc Fe/Cu/Fe system shows oscillations with a period of 2 ML
214 citations
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09 Feb 2003TL;DR: In this paper, an I and Q continuous-time fifth-order /spl Sigma/spl Delta/ modulator with 1-bit quantizer and SC feedback DAC is presented, which demonstrates the improvement in maximum achievable SNR when using an SC instead of a switched-current (SI) feedback circuit.
Abstract: Time jitter in continuous-time /spl Sigma//spl Delta/ modulators is a known limitation on the maximum achievable signal-to-noise-ratio (SNR). Analysis of time jitter in this type of converter shows that a switched-capacitor (SC) feedback digital-to-analog converter (DAC) reduces the sensitivity to time jitter significantly. In this paper, an I and Q continuous-time fifth-order /spl Sigma//spl Delta/ modulator with 1-bit quantizer and SC feedback DAC is presented, which demonstrates the improvement in maximum achievable SNR when using an SC instead of a switched-current (SI) feedback circuit. The modulator is designed for a GSM/CDMA2000/UMTS receiver and achieves a dynamic range of 92/83/72 dB in 200/1228/3840 kHz, respectively. The intermodulation distance IM2, 3 is better than 87 dB in all modes. Both the I and Q modulator consumes a power of 3.8/4.1/4.5 mW at 1.8 V. Processed in 0.18-/spl mu/m CMOS, the 0.55-mm/sup 2/ integrated circuit includes a phase-locked loop, two oscillators, and a bandgap.
214 citations
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TL;DR: This paper proposes three basic building blocks for spectral-agile systems, namely spectrum opportunity discovery, spectrum opportunity management, and spectrum usage coordination, and develops protocols for each blocks, and proposes protocols that can improve the throughput of an IEEE 802.11 wireless LAN.
Abstract: Static spectrum allocation prohibits radio devices from using spectral bands designated for others. As a result, some bands are under-utilized while other bands are over-populated with radio devices. To remedy this problem, the concept of spectrum agility has been considered so as to enable devices to opportunistically utilize others' spectral bands. In order to help realize this concept, we establish an analytical model to derive performance metrics, including spectrum utilization and spectrum-access blocking time in spectral-agile communication systems. We then propose three basic building blocks for spectral-agile systems, namely spectrum opportunity discovery, spectrum opportunity management, and spectrum usage coordination, and develop protocols for each blocks. These protocols are integrated with the IEEE 802.11 protocol, and simulated using ns-2 to evaluate the protocol overhead. The simulation results show that our proposed protocols can improve the throughput of an IEEE 802.11 wireless LAN by 90% for the simulated scenarios, and the improvements matched well our analytical model. These results demonstrate the great potential of using spectrum agility for improving spectral utilization in an efficient, distributed, and autonomous manner
214 citations
Authors
Showing all 68268 results
Name | H-index | Papers | Citations |
---|---|---|---|
Mark Raymond Adams | 147 | 1187 | 135038 |
Dario R. Alessi | 136 | 354 | 74753 |
Mohammad Khaja Nazeeruddin | 129 | 646 | 85630 |
Sanjay Kumar | 120 | 2052 | 82620 |
Mark W. Dewhirst | 116 | 797 | 57525 |
Carl G. Figdor | 116 | 566 | 52145 |
Mathias Fink | 116 | 900 | 51759 |
David B. Solit | 114 | 469 | 52340 |
Giulio Tononi | 114 | 511 | 58519 |
Jie Wu | 112 | 1537 | 56708 |
Claire M. Fraser | 108 | 352 | 76292 |
Michael F. Berger | 107 | 540 | 52426 |
Nikolaus Schultz | 106 | 297 | 120240 |
Rolf Müller | 104 | 905 | 50027 |
Warren J. Manning | 102 | 606 | 38781 |