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.

Graphite filaments having tubular structure and method of forming the same

Abstract: A graphite filament which has carbon as a basic structural unit and which have a tubular shape being formed with a helical structure with the carbon hexagons as a main structure and with an outer diameter of 30 nm or less. The tubular lattices a 1 to a 3 are a multiple structure and the interval between inner and outer adjacent tubules is about 0.34 nm, which is similar to the interval between basal planes of graphitic structure. The graphite filament is a new carbon filament material having a structure that is different from a normal graphite filament.

Pulse-time modulated plasma discharge for highly selective, highly anisotropic and charge-free etching

Abstract: Highly selective, highly anisotropic, notch-free and charge-build-up damage-free polycrystalline silicon etching is performed by using electron cyclotron resonance plasma modulated at a pulse timing of a few tens of microseconds. A large quantity of negative ions is produced in the afterglow of the pulse-time modulated plasma. The decay times of electron density, electron temperature and sheath potential are considerably reduced, which is attributable to negative ion generation. Furthermore, the pulse-time modulated plasma reduces the time-averaged sheath potential. As a result of these effects, charged particles in the sheath are strongly modified from the continuous discharge, and they should improve selective etching in the pulsed ECR plasma and elimination of charge accumulation on the substrate.

Mobile communication system, communication control method, and base station and mobile station to be employed in the same

Abstract: In the communication system performing transmission with generating the vacant period in the slotted mode during data transmission in order to perform various process, such as different frequency carrier quality measurement or so forth, the control signal for maintaining a communication quality is inserted even in the vacant period. Therefor, a link quality may not be degraded even if the vacant period is long. Namely, when the pilot signal is used as the control signal, even in the vacant period, measurement of the link quality of the forward link with the pilot signal is performed in the mobile station to report the result of measurement to the base station. Therefore, transmission power control of the forward link can be performed according to the report in the base station. Therefore, degradation of the forward link can be eliminated.

3.8-THz wavelength conversion of picosecond pulses using a semiconductor delayed-interference signal-wavelength converter (DISC)

Abstract: A new all-optical semiconductor-band-filling-based wavelength converter, named delayed-interference signal-wavelength converter (DISC), is proposed. Its speed is not restricted by the carrier lifetime and its structure is very simple: it consists of only two essential components, namely, a semiconductor optical amplifier and a passive split-delay. Using this converter, 3.8-THz-shifted (from 1530 to 1560-nm) 14-ps-long pulses are generated from 1530-nm 140-fJ 0.7-ps pulses with high-conversion efficiency.