Abstract: To provide a semiconductor memory device comprising a plurality of silicon pillars arranged in a matrix, whose sidewalls are provided with gate electrodes with gate insulating films interposed between the silicon pillars and the gate electrodes and whose top ends are electrically connected to memory elements, and a bit line and a word line provided between the silicon pillars so as to be orthogonal to each other. The bit line is electrically connected to a bottom end of the silicon pillars on both sides of the bit line in alternate rows, and the word line is electrically connected to a gate electrode formed on a sidewall of the silicon pillars on both sides of the word line in alternate columns.

Abstract: A positioning receiver and method in which the time required for signal acquisition can be reduced and positioning time can be reduced by increasing the occasion of the signal acquisition. In an SPS receiver mounted user equipment (100), a Doppler shift amount measuring means (112a) of a frequency search range control unit (112) measures the Doppler shift amount of the signals from a plurality of base stations of a communication network. A search range control means (112b) calculates the difference between the maximum value and minimum value of the measured Doppler shift amount of the base stations and determines the search range at the time of satellite signal search by comparing the difference and a predetermined threshold. The search range control means (112b), if it is judged that the difference between the maximum value and minimum value of the Doppler shift amount is larger than the threshold, sets the search range larger and, if not, sets the search range less.

Abstract: A semiconductor device includes a semiconductor pillar, an insulator, and an electrode. The semiconductor pillar has a semiconductor portion outwardly extending. The insulator extends along the semiconductor pillar. The insulator has an insulating portion outwardly extending along the semiconductor portion. The electrode extends along the insulator. The insulator is between the semiconductor pillar and the electrode. The electrode has an electrode portion overlapping the insulating portion in plain view. The electrode portion is under the insulating portion.

Abstract: A method of manufacturing a semiconductor device includes forming silicon pillar 11 on substrate 10, forming a protective film which covers an upper end portion and a lower end portion of a side surface of silicon pillar 11, forming a constricted portion by anisotropic etching in a portion of the side surface of silicon pillar 11 which is not covered with the protective film after forming the protective film, removing the protective film after forming the constricted portion, forming gate oxide film 12 which covers the side surface of silicon pillar 11 in which the constricted portion is formed, and forming gate electrode 13 which covers gate oxide film 12.

Abstract: A signal capturing apparatus and a signal capturing method wherein the timing at which to implement the clock frequency correction of a GPS reception part during position determination can be optimized to prevent any search omissions, while shortening the time period required for the position determination. A cellular clock precision estimating function part (120) estimates a reception quality of wireless communication. When an estimated reception quality is equal to or greater than a predetermined threshold value, a corrected timing deciding part (140) implements a GPS clock frequency correction with the cellular clock used as a reference. When the reception quality is less than the predetermined threshold value, the corrected timing deciding part (140) inhibits the GPS clock frequency correction from being implemented with the cellular clock used as a reference.

Abstract: A positioning receiver in which the circuit configuration of the receiving system corresponding to a plurality of positioning systems can be simplified and the current consumption and circuit size of which can be reduced. A positioning receiver (100) comprises first low-pass filters (111, 121) which limit outputs of a first signal mixer (103) and a second signal mixer (104) to a first bandwidth, and second low-pass filters (112, 122) which are provided on the output side of the first low-pass filters (111, 121) and limit the outputs of the first low-pass filters (111, 121) to a second bandwidth narrower than the first bandwidth and sets the filter bandwidth of the first low-pass filters (111, 121) greater than that of the second low-pass filters (112, 122).

Abstract: An object of this invention is to provide a modulator, an optical transmitter and an optical transfer device which can modulate a channel signal while suppressing residual AM signals regardless of the frequency of a channel signal and suppressing deterioration of the channel signal due to impossibility of giving a sufficient FM demodulation amplitude.

Abstract: A semiconductor device is provided in which two adjacent cell lines extending in a word line direction are connected by one word line. Additionally, A semiconductor device comprising: word lines; bit lines which are disposed to cross the word lines; a plurality of cell lines extending in a word line direction; and a word line provided to share one cell line and the other cell line, of a pair of cell lines comprising two adjacent cell lines, wherein a distance between two adjacent cell lines in the pair of cell lines is smaller than a distance between two adjacent cell lines between one pair of cell lines and the other pair of cell lines.

Abstract: An object of this invention is to provide a modulator, an optical transmitter and an optical transfer device which can modulate a channel signal while suppressing residual AM signals regardless of the frequency of a channel signal and suppressing deterioration of the channel signal due to impossibility of giving a sufficient FM demodulation amplitude.

Abstract: Providing an optical transceiver module that reduces electric crosstalk between a light emitting device and a photodetector while providing an excellent high-frequency characteristic, and an optical transceiver including the same. According to the invention, a first metal plate having a first substrate for mounting a light emitting device and a at second metal plate having a second substrate for mounting a photodetector are provided separately and independently of each other in a resin package, thus reducing the parasitic capacitance. This provides an optical transceiver module capable of suppressing electric crosstalk where part of a high-frequency signal causes a variation in the potential at a terminal of a photodetector while improving the high frequency characteristic in driving the light emitting device with a high-frequency signal, and an optical transceiver including the same.

Abstract: The subject of the present invention is to provide an optical transmitting device and an optical transmission system, capable of realizing an increase of multiple channels and an extension of a transmission distance at a low cost. In the present invention, the external modulation process is applied to a first optical signal (?1), which is modulated by a transmission signal on a low frequency side for which low noise and distortion characteristics are required, out of the wideband frequency multiplexing electric signals by a first E/O converting unit (22). In contrast, the direct modulation process is applied to a second optical signal (?2), which is modulated by a transmission signal on a high frequency side whose request for the transmission characteristic is not so high, by a second E/O converting unit (24) to execute an E/O conversion.

Abstract: In a multi-channel video optical transmission system comprising an optical transmitter and an optical receiver, a frequency modulation function incorporated pilot signal generating unit is provided in the optical transmitter to generate a pilot signal frequency-modulated. This frequency-modulated pilot signal is superimposed on a multi-channel video signal inputted thereto and is converted into a frequency-modulated signal in a frequency modulator, and is transmitted through an optical fiber to an optical receiver in a state converted into an optical signal in a semiconductor laser device. In the optical receiver, the optical signal is again converted into an electric frequency-modulated signal in a light-receiving device and, after amplified in an amplifier, is demodulated in a frequency demodulator, thereby regenerating the multi-channel video signal before the input to the frequency modulator.

Abstract: Even when wavelength number of input optical signals is changed, or when the optical signals are intermittently transmitted e.g. in the case of the optical packet signals, amplification with constant output intensities for respective wavelengths is provided. An optical amplifier of the invention comprises a semiconductor laser which outputs light having a constant intensity and a given wavelength &lgr; L, a semiconductor optical amplifier which amplifies part of the input optical signals and output light from the semiconductor laser, an optical filter which extracts only an optic element having a wavelength of &lgr; L among the output light therefrom, a means which provides a rare earth ion-doped optical fiber with other part of the input optical signals and the extracted optic element having a wavelength of &lgr; L.

Abstract: In a signal transmission system made up of a transmission section, a receive section and an optical fiber installed between the transmission section and the receive section, a harmonic producing circuit and a harmonic phase shifting circuit are provided on the downstream side of an FM modulator. The harmonic producing circuit superimposes a harmonic of an FM signal on the FM signal, and the harmonic phase shifting circuit shifts the phase of the harmonic. This arrangement compensates a group delay deviation occurring in system components when an AM signal or QAM signal is modulated into an FM signal or PM signal in a modulator and then transmitted to be demodulated in a demodulator, thereby improving transmission quantity.

Abstract: Provided is a wavelength converter utilizing gain non-linearity of a semiconductor optical amplifier for suppressing the degradation of extinction ratio when an inputted signal light undergoes wavelength conversion. In the wavelength converter, a first semiconductor laser outputs an optical signal with a first wavelength to be obtained when the inputted signal light undergoes the wavelength conversion, and a second semiconductor laser outputs an optical signal with a second wavelength which is in opposite phase relation to the optical signal from the first semiconductor laser, thereby producing a Mach-Zehnder interferometer. This Mach-Zehnder interferometer enables a high level of the optical signal with the second wavelength in the opposite phase relation to cancel a low level of the optical signal with the first wavelength after passing through a semiconductor optical amplifier, thus improving the extinction ratio.

Abstract: In an automatic gain control circuit comprising a variable gain amplifying circuit for amplifying an input signal through the use of variable gain control to send out an output signal and a gain control circuit for amplitude-controlling the input signal fed into the variable gain amplifying circuit, a peak detecting circuit of the variable gain amplifying circuit detects a peak voltage value of the output signal, and the gain control circuit generates an amplitude control signal corresponding to an amplitude value of the output signal. The generated amplitude control signal is fed back to the variable gain amplifying circuit for controlling the amplitude of the output signal to a constant value with respect to amplitude variations of the input signal. With this arrangement, even if a largely amplitude-varying input signal appears, the gain control circuit can control the amplitude of the output signal readily to a constant value.

Abstract: There is disclosed a constitution in an FM demodulator of a delay detection system for solving a problem that a demodulated signal is distorted because of a dragging or undershoot in an output pulse of an AND gate for outputting a logical product, the FM demodulator comprising: a limiter circuit which responds to an inputted FM signal; a delay circuit which delays one of two outputs; an AND gate into which another output of the limiter circuit and an output of the delay circuit are inputted; and a low-pass filter 4 into which an output of the AND gate is inputted, wherein tilted frequency characteristics are imparted to group delay of the delay circuit, the group delay frequency characteristics impart nonlinearity to fV characteristics, the fV characteristics are thereby inversely corrected, and linearity is improved.

Abstract: In an automatic gain control circuit comprising a variable gain amplifying circuit for amplifying an input signal through the use of variable gain control to send out an output signal and a gain control circuit for amplitude-controlling the input signal fed into the variable gain amplifying circuit, a peak detecting circuit of the variable gain amplifying circuit detects a peak voltage value of the output signal, and the gain control circuit generates an amplitude control signal corresponding to an amplitude value of the output signal. The generated amplitude control signal is fed back to the variable gain amplifying circuit for controlling the amplitude of the output signal to a constant value with respect to amplitude variations of the input signal. With this arrangement, even if a largely amplitude-varying input signal appears, the gain control circuit can control the amplitude of the output signal readily to a constant value.

Abstract: In a multi-channel video optical transmission system comprising an optical transmitter and an optical receiver, a frequency modulation function incorporated pilot signal generating unit is provided in the optical transmitter to generate a pilot signal frequency-modulated. This frequency-modulated pilot signal is superimposed on a multi-channel video signal inputted thereto and is converted into a frequency-modulated signal in a frequency modulator, and is transmitted through an optical fiber to an optical receiver in a state converted into an optical signal in a semiconductor laser device. In the optical receiver, the optical signal is again converted into an electric frequency-modulated signal in a light-receiving device and, after amplified in an amplifier, is demodulated in a frequency demodulator, thereby regenerating the multi-channel video signal before the input to the frequency modulator.

Abstract: In a signal transmission system made up of a transmission section, a receive section and an optical fiber installed between the transmission section and the receive section, a harmonic producing circuit and a harmonic phase shifting circuit are provided on the downstream side of an FM modulator. The harmonic producing circuit superimposes a harmonic of an FM signal on the FM signal, and the harmonic phase shifting circuit shifts the phase of the harmonic. This arrangement compensates a group delay deviation occurring in system components when an AM signal or QAM signal is modulated into an FM signal or PM signal in a modulator and then transmitted to be demodulated in a demodulator, thereby improving transmission quantity.