Abstract: A radiation type oscillator including a radiation type oscillator substrate including a microwave transistor for generating negative resistance by short-duration operation and a resonant cavity structure; a high-frequency pulse signal of an oscillation frequency/frequency bandwidth determined by negative resistance produced by the short-duration operation of the microwave transistor and the resonant cavity structure is generated as a transmitted RF signal and simultaneously radiated into space. The radiation type oscillator performs oscillating operation when a received RF signal that is a reflected wave of the transmitted RF signal from an object of detection enters the radiation type oscillator, an IF signal is acquired from an IF signal output terminal owing to homodyne mixing by the radiation type oscillator itself, and this is analyzed and processed to detect the object of detection.

Abstract: To provide a microwave/milliwave band high-frequency pulse signal generating device that enables realization of structural simplification, high performance, compact integration, easy design, low power consumption, and low cost.

Abstract: To provide a microwave/milliwave UWB pulse wireless communication device that enables realization of structural simplification, high performance, compact integration, easy design, low power consumption, and low cost.

Abstract: A baseband signal processing unit changes the collector current of a transistor (20) formed by a bias control circuit (7) in accordance with a baseband transmission signal input from a baseband signal input terminal (18), changing the drain bias of a high-frequency transistor (1) to realize frequency modulation by changing the oscillation frequency, and the radiation wave thereof forms a transmit RF signal, whereby the transmission operation is performed. On the other hand, the oscillation signal is synchronized with a frequency modulated RF signal that arrives from outside, the change in frequency caused by the frequency modulation is generated as a change in the drain bias of the high-frequency transistor (1), and reception operation is performed by taking out that change as a voltage amplitude change from the baseband signal output terminal (14). As a result, it is possible to provide a microwave/millimeter wave communication apparatus that is simple in structure, low cost, and low power consumption.

Abstract: To provide a microwave/milliwave band high-frequency pulse signal generating device that enables realization of structural simplification, high performance, compact integration, easy design, low power consumption, and low cost.

Abstract: A radiation type oscillator including a radiation type oscillator substrate including a microwave transistor for generating negative resistance by short-duration operation and a resonant cavity structure; a high-frequency pulse signal of an oscillation frequency/frequency bandwidth determined by negative resistance produced by the short-duration operation of the microwave transistor and the resonant cavity structure is generated as a transmitted RF signal and simultaneously radiated into space. The radiation type oscillator performs oscillating operation when a received RF signal that is a reflected wave of the transmitted RF signal from an object of detection enters the radiation type oscillator, an IF signal is acquired from an IF signal output terminal owing to homodyne mixing by the radiation type oscillator itself, and this is analyzed and processed to detect the object of detection.

Abstract: To provide a microwave/milliwave UWB pulse wireless communication device that enables realization of structural simplification, high performance, compact integration, easy design, low power consumption, and low cost.

Abstract: A baseband signal processing unit changes the collector current of a transistor (20) formed by a bias control circuit (7) in accordance with a baseband transmission signal input from a baseband signal input terminal (18), changing the drain bias of a high-frequency transistor (1) to realize frequency modulation by changing the oscillation frequency, and the radiation wave thereof forms a transmit RF signal, whereby the transmission operation is performed. On the other hand, the oscillation signal is synchronized with a frequency modulated RF signal that arrives from outside, the change in frequency caused by the frequency modulation is generated as a change in the drain bias of the high-frequency transistor (1), and reception operation is performed by taking out that change as a voltage amplitude change from the baseband signal output terminal (14). As a result, it is possible to provide a microwave/millimeter wave communication apparatus that is simple in structure, low cost, and low power consumption.

Abstract: An optical receiver including an optical divider to divide a signal light from an optical transmission line into two portions, a first and a second dispersion compensators, each dispersion compensator having variable dispersion compensation to compensate chromatic dispersions of each of the two portions of signal light output from the optical divider, and a data demodulator to demodulate a data carried by a signal light output from the first dispersion compensator. The optical receiver further includes an optical autocorrelator to operate on a signal light output from the second dispersion compensator and a controller to control the second dispersion compensator to increase autocorrelation of the optical autocorrelator, and to control the first dispersion compensator according to the result of said controlling the second dispersion compensator.

Abstract: A communication zone is defined by a plurality of cells, which are separated from one another and has respective fixed base stations. The base stations in the first cell and the last cell are capable of bidirectional communication with a mobile station, while other base stations are capable of unidirectional communication. The base stations are connected to a zone control station, which controls communications with the mobile station within the zone.

Abstract: Each of a transmitter (1) and a receiver (2) divides temporarily-shared data into one or more purification blocks and one or more disposable blocks, and mixes each purification block so as to enlarge a Hamming distance between corresponding purification blocks being held by the transmitter (1) and the receiver (2) by using a Hamming distance amplification effect. The transmitter (1) Vernam-encrypts the mixed data with the disposable data and transmits the mixed data to the receiver (2), and the receiver (2) decrypts the received Vernam-encrypted data by using a disposable block owned thereby, and compares the Hamming distance between the purification block owned thereby with the mixed data with a predetermined value so as to judge whether each purification block can be shared between the transmitter (1) and the receiver (2).

Abstract: A communication satellite facility and a satellite communication system adapted to respond flexibly to development and change of communication technologies occurring on the ground even after satellites have been launched. The system includes a first satellite having an antenna function, a second satellite having a modem function and a third satellite having a server function all of which are launched into one and same slot of geosynchronous orbit and connected one to another by wideband intersatellite communication. A ground station connected to a ground network communicates with the first satellite.

Abstract: Upon recovery of communication, this recovery is detected by communication recover detector and then optimal times duplicated pseudo acknowledgements calculated by arithmetic unit are transmitted from ACK transmitter. During normal state, advertisement is made in small value of advertised receive window size and immediately after recovery state, advertisement is made in expanded window size.

Abstract: A method and apparatus are provided that make it possible to speedily measure, and obtain images of, the three-dimensional distribution of electric fields in integrated circuits, using electro-optic sampling. The sampling is performed using a plurality of electric field sensors, each comprising an electro-optic crystal layer, a light-reflecting layer that is in close contact with the electro-optic crystal layer, and a separation layer that is in close contact with the reflection layer, separating the reflection layer from the object to be measured.

Abstract: The present invention is directed to improve convenience to the user. A path extending from the present location S of a mobile terminal to a destination D via a base station is calculated (S2), distances between base stations on the calculated path and the present location are calculated, and the closest base station is determined as a contents delivery base station (S7). Grace time for the mobile terminal to pass through the contents delivery base station is calculated. Then, scheduled time to deliver the contents to the mobile terminal is calculated (S8). While monitoring a travel state of the mobile terminal (S10 to S12), the contents are delivered to the mobile terminal near the contents delivery base station (S14).

Abstract: To create a network that connects a plurality of wireless communication systems to create optimal systems for various environments, and that seamlessly integrates the resulting systems together in order to provide more efficient and advanced service in general. A network system that can seamlessly integrate wireless communication systems employs a heterogeneous network architecture with at least four building blocks, including a mobile host 40, a wireless access network 41, a common core network 42, and an external network 43.

Abstract: A method of easily manufacturing a nano-gap electrode by using a focused ion beam lithography includes a layer depositing step of depositing an electrode layer and a metal mask layer in this order on an insulating substrate, a mask pattern forming step of etching the metal mask layer by using the focused ion beam and thereby forming a mask pattern, a dry etching step of transferring a pattern to the electrode layer by dry etching, and a wet etching step of removing the metal mask layer by using a solution that selectively dissolves the metal mask layer compared to the electrode layer.

Abstract: Only a first radio station is equipped with a local oscillation signal source. A signal transmitted to a second radio station includes local oscilaation signal components used to up-convert a modulated intermediate frequency band signal in addition to intermediate frequency band signal components. The second radio station that receives the signal from the first radio station extracts and regenerate the local oscillation signal used at the first radio station using a local oscillation signal regenerator. The extracted and regenerated local oscillation signal is used to down-convert modulated radio signal components to the intermediate frequency band and simultaneously up-convert to the radio frequency band the modulated intermediate frequency band signal to be transmitted to the first radio station.

Abstract: This apparatus calculates a direction of a light source (the sun) in a coordinate system having a 3D geometrical model of an object placed therein from geographic information on an object and a shooting time of image data, and detects a shadow region cast on the 3D geometrical model by a beam from a light source direction so as to identify the shadow region in the image data based on correspondence information. It uses a predetermined reflection model to estimate effects of shadings caused to the 3D geometrical model and determines a parameter of a reflection model suited to estimated shadings. And it performs calculation for removing the effects of the shadows and shadings by using the determined parameter from pixel values sampled from the image data so as to fit the calculated pixel values in the 3D geometrical model and generate a texture model.

Abstract: Here is disclosed a method for generation of a molecular beam from a sample solution, comprising steps of operating a spray-in device to introduce the sample solution in atomized state into a spray chamber, impinging a suitable gas on the sample solution in atomized state or heating the sample solution in atomized state to generate solute molecules deprived of solvent molecules, and then ejecting these solute molecules through an orifice into a low air pressure chamber. The apparatus as well as the method according to the present invention enable to generate a molecular beam for a variety of molecules, particularly for the neutral molecules which can be decomposed by heating at a high temperature or those which can not be sublimated or vaporized even by heating at a high temperature, as long as the sample solutions are prepared.