Mitsubishi Denki Kabushiki Kaisha

Other

Ntt Docomo, Inc.

Susumu Yoshida

Tsutomu Takeuchi

Sirikiat Ariyavisitakul

Fumio Ikegami

Takao Oda

Kotaro Mitsui

Takafumi Nishioka

Mari Kato

Takahiro Asai

Katsumi Sato

Jaturong Sangiamwong

Hidekazu Murata

Masaaki Sasada

A radio communications apparatus is disclosed which includes a generator which generates a transmit frame; and a transmitter which transmits the transmit frame via multiple transmit antennas. In the radio communications apparatus, the transmit frame includes a predetermined number of resource elements having a predetermined frequency bandwidth and a predetermined symbol period, and the generator generates the transmit frame such that the number of transmit antennas which are identifiable from a location of the resource element taken up by a pilot signal in a certain transmit frame is less than the number of transmit antennas which are identifiable from the location of the resource element taken up by the pilot signal in a retransmission transmit frame of the certain transmit frame.

Radio communications apparatus, radio communications method, and radio communications system for reducing overhead of a transmit frame

A first conductivity type first semiconductor layer is formed on an insulation substrate and a second conductivity type second semiconductor layer is formed on the first semiconductor layer in order to provide a semiconductor device having a highly reliable electrode structure. In order to accomplish this electrode structure, a first electrode which is insulated from the first semiconductor layer with an insulation film, is formed on an area extending from a part of the second semiconductor layer to an exposed surface of the insulation substrate which is not covered with the first semiconductor layer. A second electrode, which is separate from the second semiconductor layer, is formed on a part of the first semiconductor layer which is not covered with the second semiconductor layer. Using this construction, a solar battery cell can be realized. Additionally, the first electrode has a connection region on the exposed surface of the insulation substrate in order to provide connection with an external terminal. This enables welding or bonding with an external terminal on this particular connection region.

Photoelectric conversion semiconductor device

In a light emitting diode array, an N-electrode layer (32) is extended from the bottom surface to the top surface of a semiconductor body (30) through the side surface. PN junctions (42) are exposed to the cleavage surface (S) and light is emitted therefrom. Since the N-electrode layer and P-electrode layers (41) are located on a common surface, the LED array can be mounted on a base plate through a soldering process. The LED array can be used without a self-focus lens array in an electric printer for photography.

Method of making a light emitting diode array

Semiconductor layers having a p-n junction are formed over the surface of a semiconductor substrate except for a partial surface. On the partial surface of the semiconductor substrate, a region of an electrode to be connected with an external terminal is formed with an insulating film interposed between the same. Bonding connection with the external terminal is performed on the region for connection, to reduce mechanical damage of the semiconductor layers having the p-n junction while improving photoelectric conversion efficiency and reliability of the device.

Method of making a semiconductor device

Light emitting diode array with electrodes

A tandem solar cell device includes an upper solar cell, a lower solar cell, and an intervening buffer layer. A short wavelength region of the incident light is absorbed by the upper solar cell while the light having passed through the upper solar cell is absorbed by the lower solar cell. The buffer layer is a semiconductor layer having a larger band gap energy than the upper solar cell, a crystalline lattice match with the upper solar cell, and a tunnel junction.

Tandem solar cell

Semiconductor device

Digital communication system

A digital communication system, in which digital information is represented by a quaternary information symbol (11, 01, 00, 10) and the double step phase shift, each step represented by (.pi./4, 3.pi./4, 5.pi./4, 7.pi./4), is performed per 1/2 time slot in correspondence to each information symbol, so that the number of phase shift per unit time in the case of the identical transmission rate can be decreased to 1/2, as compared with a .DELTA..theta./2-DSK system, and expansion of the bandwidth can be decreased to 1/2.

The present invention provides a digital communication system in which one time slot is divided into a first half section and a second half section and the carrier phase difference .theta. between each neighboring first half section is set to either (.pi., 0) with respect to a binary information symbol (1,0) or (0, .pi./2, .pi., 3/2.pi.) with respect to a quaternary information symbol (11, 01, 00, 10). In addition, the phase difference .psi. between the first half and the second half of any time slot is a constant value .psi..sub.0 (for example, .pi.rad) irrespective of the symbol, or .psi..sub.i determined with respect to a symbol (for example, +.pi./2 with respect to a symbol 1 or -.pi./2 with respect to a symbol 0). Therefore, an arbitrary complementary characteristic can be obtained when differentially demodulated in a multipath fading channel, irrespective of the amplitude characteristic of a demodulation signal.

After a liquid-phase epitaxial growth step by an n-type GaAs saturated solution is terminated, a substrate is temporarily dipped in an undoped GaAs saturated or supersaturated solution, and thereafter liquid-phase epitaxial growth is performed by a p-type Al.sub.x Ga.sub.1-x As saturated solution. Thus, the n-type GaAs saturated solution is prevented from being mixed into the p-type Al.sub.x Ga.sub.1-x As saturated solution to contaminate the same, whereby a solar battery of high quality can be obtained even if the number of times of crystallization is increased.

Method of manufacturing Group III-V compound semiconductor solar battery

A solution for crystal growth reserved in an upper chamber is taken from an opening formed in a slider mounted between the upper chamber and a middle chamber, and flown to the middle chamber containing a substrate, solid bodies in the solution being removed by two grids attached to a hole provided on the side of the middle chamber.

Boat for liquid phase epitaxial growth

The present invention provides a communication system which employs a signal whose carrier phase is shifted by a constant amount .DELTA..theta. per time slot in correspondence to each symbol (1 or 0) transmitted, and the phase shift is performed by .DELTA..theta./2 (or -.DELTA..theta./2) in the first 1/2 time slot and further by .DELTA..theta./2 (or -.DELTA..theta./2) in the second 1/2 time slot thereby to improve the bit error rate in multipath propagation.

A semiconductor light-electricity conversion device, includes: a Group III-V compound semiconductor region having a pn junction therein and including gallium and arsenic; a silicon region having a pn junction; a zinc selenide layer inserted between said two regions; and a plurality of electrodes for outputting light generated current from said two regions.

Light-electricity conversion semiconductor device

An antireflective film (7, 8) for photoelectric devices comprises at least a layer having a refractive index being the largest on the side abutting on the light receiving surface (2a) or the light emitting surface of a photoelectric device and continuously decreasing according to the distance outward from said side.

Growing community of inventors

Itami, Japan

Susumu Yoshida