NEC

About: NEC is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 33269 authors who have published 57670 publications receiving 835952 citations. The organization is also known as: NEC Corporation & NEC Electronics Corporation.

Broad conical-mode helical antenna

Abstract: In a helical antenna where a helical conductor is spirally wound on a coaxial cable, spacings between turns of the helical conductor are changed in accordance with the positions of the turns.

Graphene-Like-Graphite as Fast-Chargeable and High-Capacity Anode Materials for Lithium Ion Batteries

Abstract: Here we propose the use of a carbon material called graphene-like-graphite (GLG) as anode material of lithium ion batteries that delivers a high capacity of 608 mAh/g and provides superior rate capability. The morphology and crystal structure of GLG are quite similar to those of graphite, which is currently used as the anode material of lithium ion batteries. Therefore, it is expected to be used in the same manner of conventional graphite materials to fabricate the cells. Based on the data obtained from various spectroscopic techniques, we propose a structural GLG model in which nanopores and pairs of C-O-C units are introduced within the carbon layers stacked with three-dimensional regularity. Three types of highly ionic lithium ions are found in fully charged GLG and stored between its layers. The oxygen atoms introduced within the carbon layers seem to play an important role in accommodating a large amount of lithium ions in GLG. Moreover, the large increase in the interlayer spacing observed for fully charged GLG is ascribed to the migration of oxygen atoms within the carbon layer introduced in the state of C-O-C to the interlayer space maintaining one of the C-O bonds.

Interconnecting substrate for carrying semiconductor device, method of producing thereof and package of semiconductor device

Abstract: An interconnecting substrate for carrying a semiconductor device, comprising: an insulating layer; an interconnection set on an obverse surface of the insulating layer; an electrode which is set on a reverse surface side of the insulating layer and formed in such a way that, at least, a lateral face of an obverse end of the electrode is all round brought into contact with the insulating layer, while, at least, a reverse surface of the electrode is not in contact with said insulating layer; a via conductor which is disposed on an obverse surface of the electrode and formed in the insulating layer so as to connect this electrode with the interconnection; and a supporting structure on the surface of the insulating layer.

Liquid cooling system for LSI packages

Abstract: In a liquid cooling system for a printed circuit board on which integrated circuit packages are mounted, heat sinks are secured respectively to the packages in heat transfer contact therewith. Nozzles are provided in positions corresponding to the heat sinks. A housing is tightly sealed to the printed circuit board to enclose the packages, heat sinks and nozzles in a cooling chamber. A feed pump pressurizes working liquid cooled by a heat exchanger and supplies the pressurized liquid to the nozzles for ejecting liquid droplets to the heat sinks. A liquid suction pump is connected to an outlet of the housing for draining liquid coolant to the heat exchanger and a vapor suction pump is connected to a second outlet of the housing for sucking vaporized coolant to the heat exchanger. The cooling chamber is maintained at a sub-atmospheric pressure to promote nucleate boiling of the working fluid.

Mobile communication system

Abstract: A cellular mobile communication system in which each of one or more cells is provided with a base radio station, and mobile terminals communicate with the base radio stations. Base radio stations (21, 22 and 23) are connected to a central base station (100) by optical fibers. The central base station is connected to a mobile switching center (50). Each of the base radio stations is provided with an O/E converter (201) and E/O converter (207). The O/E converter converts a optical signal containing speech signals and a call connection control signal into RF signals. The E/O converter (207) converts RF signals, received from a mobile terminal (11) via an antenna (204), into optical signals and transmits the optical signals to the central base station. The central base station comprises O/E converters (301-303) for converting optical signals from each base radio station into RF signals; receivers (401-403) for demodulating these RF signals; transmitters (406-408) for converting speech signals and a call connection control signal from the mobile switching center into RF signals; and E/O converters (304-306) for converting these RF signals into optical signals and transmitting the optical signals to a base radio station.