Abstract: The normality verification and radio characteristics test of a radio communication system are executed. RF-SWs (radio-frequency coaxial switches) change-over the paths of signals which are transmitted to and received from an access terminal function portion included in an access point. RF-SWs connect the access terminal function portion 122 with a desired one of radio analog portions. A test function controller controls the changeover operations of the RF-SWs in accordance with information designated by a maintenance apparatus (OMC). An access point controller controls in accordance with received test sort information, one or more of (1) an antenna failure test, (2) a receiver failure test, and (3) a transmitter failure.

Abstract: A reception sensitivity is measured at a high precision. An access terminal function portion includes the transmitter part and receiver part of a communication terminal in a radio communication system. A path switch part effects switching to connect the input ends of receivers to antennas or to terminate them. The path switch part switches the paths of a signal from a transmitter and signals toward the receivers. An access point controller adjusts a packet error rate into a predetermined range, and obtains the reception sensitivity based on the transmission power of the access terminal function portion after the adjustment.

Abstract: A method for fabricating a semiconductor light-emitting element according to the present invention includes the steps of (A) providing a striped masking layer on a first Group III-V compound semiconductor, (B) selectively growing a second Group III-V compound semiconductor over the entire surface of the first Group III-V compound semiconductor except a portion covered with the masking layer, thereby forming a current confining layer that has a striped opening defined by the masking layer, (C) selectively removing the masking layer, and (D) growing a third Group III-V compound semiconductor to cover the surface of the first Group III-V compound semiconductor, which is exposed through the striped opening, and the surface of the current confining layer.

Abstract: The normality verification and radio characteristics test of a radio communication system are executed. RF-SWs (radio-frequency coaxial switches) change-over the paths of signals which are transmitted to and received from an access terminal function portion included in an access point. RF-SWs connect the access terminal function portion 122 with a desired one of radio analog portions. A test function controller controls the changeover operations of the RF-SWs in accordance with information designated by a maintenance apparatus (OMC).

Abstract: A reception sensitivity is measured at a high precision. An access terminal function portion includes the transmitter part and receiver part of a communication terminal in a radio communication system. A path switch part effects switching so as to connect the input ends of receivers to antennas or to terminate them. The path switch part switches the paths of a signal from a transmitter and signals toward the receivers. An access point controller adjusts a packet error rate into a predetermined range, and obtains the reception sensitivity on the transmission power of the access terminal function portion after the adjustment.

Abstract: A semiconductor laser device according to the present invention includes: a semiconductor laser chip 1 for emitting laser light; a stem 3, 4 for supporting the semiconductor laser chip; a plurality of terminal electrodes, inserted in throughholes provided in the stem 3, 4, for supplying power to the semiconductor laser chip; and a cap 5 having an optical window 6 which transmits laser light and being affixed to the stem 3, 4 so as to cover the semiconductor laser chip 1. Between the stem 3, 4 and the terminal electrodes 7, this device includes insulation glass 8, which does not release silicon fluoride gas when heated to a temperature of no less than 700° C. and no more than 850° C.

Abstract: A nitride compound semiconductor element according to the present invention is a nitride compound semiconductor element including a substrate 1 having an upper face and a lower face and a semiconductor multilayer structure 40 supported by the upper face of the substrate 1, such that the substrate 1 and the semiconductor multilayer structure 40 have at least two cleavage planes. At least one cleavage inducing member 3 which is in contact with either one of the two cleavage planes is provided, and a size of the cleavage inducing member 3 along a direction parallel to the cleavage plane is smaller than a size of the upper face of the substrate 1 along the direction parallel to the cleavage plane.

Abstract: To permit electrical testing of a semiconductor integrated circuit device having test pads disposed at narrow pitches probes in a pyramid or trapezoidal pyramid form are formed from metal films formed by stacking a rhodium film and a nickel film successively. Via through-holes are formed in a polyimide film between interconnects and the metal films, and the interconnects are electrically connected to the metal films. A plane pattern of one of the metal films equipped with one probe and through-hole is obtained by turning a plane pattern of the other metal film equipped with the other probe and through-hole through a predetermined angle.

Abstract: There is a need for effectively compensating distortion when a predistortion transmitter is subject to not only a memory effect due to nonlinearity of an amplifier, but also a modulator's DC offset, IQ unbalance, or local quadrature error. A predistortor to be used is a polynomial predistortor including a polynomial basis generation portion and an inner product calculation portion. The polynomial basis generation portion delays a real part and an imaginary part of a complex input signal Sx=Ix+jQx for up to M samples to generate 2 (M+1) signals, duplicately combines these signals to generate monomials having maximum degree N, and outputs, as a basis vector, all or part of the monomials depending or needs. The inner product calculation portion performs an inner product calculation using a coefficient vector, i.e., a set of complex numbers sized equally to the basis vector to find a polynomial value and outputs the value as a complex signal.

Abstract: A process for producing a nitride semiconductor according to the present invention includes: step (A) of provided an n-GaN substrate 101; step (B) of forming on the substrate 101 a plurality of stripe ridges having upper faces which are parallel to a principal face of the substrate 101; step (C) of selectively growing AlxGayInzN crystals (0?x, y, z?1: x+y+z=1) 104 on the upper faces of the plurality of stripe ridges, the AlxGayInzN crystals containing an n-type impurity at a first concentration; and step (D) of growing an Alx?Gay?Inz?N crystal (0?x?, y?, z??1: x?+y?+z?=1) 106 on the AlxGayInzN crystals 104, the Alx?Gay?Inz?N crystal 106 containing an n-type impurity at a second concentration which is lower than the first concentration, and linking every two adjoining AlxGayInzN crystals 104 with the Alx?Gay?Inz?N crystal 106 to form one nitride semiconductor layer 120.

Abstract: This specification relates to a semiconductor laser in which an n-type semiconductor layer (13), an active layer (101), and a p-type semiconductor layer (24) are stacked in this order on a substrate (11), the active layer (101) comprising a well layer composed of InGaN, the semiconductor laser comprising an intermediate layer (21) sandwiched between the active layer (101) and the p-type semiconductor layer (24), and the intermediate layer including no intentionally added impurities and being composed of a gallium nitride-based compound semiconductor. This semiconductor laser has an extended lifetime under high optical output power conditions.

Abstract: This specification relates to a semiconductor laser in which an n-type semiconductor layer (13), an active layer (101), and a p-type semiconductor layer (24) are stacked in this order on a substrate (11), the active layer (101) comprising a well layer composed of InGaN, the semiconductor laser comprising an intermediate layer (21) sandwiched between the active layer (101) and the p-type semiconductor layer (24), and the intermediate layer including no intentionally added impurities and being composed of a gallium nitride-based compound semiconductor. This semiconductor laser has an extended lifetime under high optical output power conditions.

Abstract: The method for fabricating a nitride semiconductor of the present invention includes the steps of: (1) growing a first semiconductor layer made of a first group III nitride over a substrate by supplying a first group III source and a group V source containing nitrogen; and (2) growing a second semiconductor layer made of a second group III nitride on the first semiconductor layer by supplying a second group III source and a group V source containing nitrogen. At least one of the steps (1) and (2) includes the step of supplying a p-type dopant over the substrate, and an area near the interface between the first semiconductor layer and the second semiconductor layer is grown so that the density of the p-type dopant locally increases.

Abstract: A reception sensitivity is measured at a high precision. An access terminal function portion 126 includes the transmitter part 214 and receiver part 215 of a communication terminal in a radio communication system. A path switch part 132 effects switching so as to connect the input ends of receivers 134, etc. to antennas 116, etc., or to terminate them. Besides, the path switch part 132 switches the paths of a signal from a transmitter 133 and signals toward the receivers 134, etc. An access point controller 115 adjusts a packet error rate into a predetermined range, and it obtains the reception sensitivity on the basis of the transmission power of the access terminal function portion 126 after the adjustment.

Abstract: After a Group III-V compound semiconductor layer, to which a p-type dopant has been introduced, has been formed over a substrate, the compound semiconductor layer is annealed. In the stage of heating the compound semiconductor layer, atoms, deactivating the p-type dopant, are eliminated from the compound semiconductor layer by creating a temperature gradient in the compound semiconductor layer.

Abstract: A method for fabricating a nitride semiconductor laser device including a step to expose surfaces of an n-type nitride semiconductor layer (102) and a p-type nitride semiconductor layer (108); a step to cover the surface of the multi-layered semiconductor; with an insulating film (109) that has a thickness greater than the difference in levels between the exposed surface of the n-type nitride semiconductor layer (102) and the outermost surface of the p-type nitride semiconductor layer (108); a step to flatten the surface of the insulating film (109); and a step to form an n-type electrode (111) and a p-type electrode (110) electrically connected to the n-type nitride semiconductor layer (102) and the p-type nitride semiconductor layer (108), respectively. This method makes it possible to obtain a nitride semiconductor laser device that is highly reliable and exhibits an excellent heat diffusing property.

Abstract: A method for fabricating a semiconductor light-emitting element according to the present invention includes the steps of (A) providing a striped masking layer on a first Group III-V compound semiconductor, (B) selectively growing a second Group III-V compound semiconductor over the entire surface of the first Group III-V compound semiconductor except a portion covered with the masking layer, thereby forming a current confining layer that has a striped opening defined by the masking layer, (C) selectively removing the masking layer, and (D) growing a third Group III-V compound semiconductor to cover the surface of the first Group III-V compound semiconductor, which is exposed through the striped opening, and the surface of the current confining layer.

Abstract: The semiconductor light-emitting device of the present invention includes a first semiconductor layer of a first conductivity type formed substantially in a uniform thickness on a substrate and a second semiconductor layer of a second conductivity type formed substantially in a uniform thickness on the first semiconductor layer. The device further includes an active layer, formed substantially in a uniform thickness between the first semiconductor layer and the second semiconductor layer, for generating emission light. The device also comprises a first electrode for supplying a drive current to the first semiconductor layer and a second electrode for supplying a drive current to the second semiconductor layer. The device is adapted that the first or second electrode is a divided electrode comprising a plurality of conductive members spaced apart from each other.

Abstract: A method for manufacturing a semiconductor includes: a first step of forming an etching stop layer on a first semiconductor layer; and a second step of forming a second semiconductor layer made of a group III–V compound semiconductor on the etching stop layer. An etching rate for the etching stop layer by dry etching is less than an etching rate for the second semiconductor layer.

Abstract: A nitride semiconductor light-emitting device is provided including: a substrate made of a nitride semiconductor; a semiconductor layer made of a nitride semiconductor containing a p-type impurity, the semiconductor layer being formed as contacting an upper surface of the substrate; a first cladding layer made of a nitride semiconductor containing an impurity of a first conductivity type, the first cladding layer being formed on the semiconductor layer; an active layer formed on the first cladding layer; and a second cladding layer made of a nitride semiconductor containing an impurity of a second conductivity type, the second cladding layer being formed on the active layer.