Abstract: A spatial filtering adaptable for an interference wave that appears unsteadily can be implemented and also an interference canceling ability can be increased even in a condition that the interference wave does not steadily exist. At a time of non-active communication, the signals from a plurality of interference source radio communication devices 2 are received in advance by an interference signal receiving section 6 as the pre-process mode, then a resultant interference correlation matrix RI is stored in a storing section 7, and then an interference wave receiving antenna weight WI used to receive selectively the transmission signals from the interference source radio communication devices 2 is prepared based on the resultant interference correlation matrix RI.

Abstract: A wireless network system including a first terminal for sending a request-to-send signal including information on a medium use period to a second terminal before sending data, receiving a clear-to-send signal from the second terminal, and sending data to the second terminal during the medium use period; the second terminal for receiving the request-to-send signal and sending the clear-to-send signal; a third terminal for receiving the request-to-send signal and transmitting data to a fourth terminal during the medium use period; ant the fourth terminal. Thus, it is possible to prevent occurrence of a problem that when it is judged that the wireless channel is being used, transmission of the station is suppressed.

Abstract: A spatial filtering adaptable for an interference wave that appears unsteadily can be implemented and also an interference canceling ability can be increased even in a condition that the interference wave does not steadily exist. At a time of non-active communication, the signals from a plurality of interference source radio communication devices 2 are received in advance by an interference signal receiving section 6 as the pre-process mode, then a resultant interference correlation matrix RI is stored in a storing section 7, and then an interference wave receiving antenna weight WI used to receive selectively the transmission signals from the interference source radio communication devices 2 is prepared based on the resultant interference correlation matrix RI.

Abstract: An antenna comprises a ground plate which is planar; a first power feed element which is disposed separately from the ground plate by a prescribed distance and which is formed in a prescribed shape; a first parasitic element which is planar and which is formed in a prescribed shape; a first shortcircuit part which electrically connects the first parasitic element and the ground plate; and a power feed part which is electrically connected with the first power feed element, wherein the first power feed element and the first parasitic element are disposed in parallel in part with each other, and the first power feed element and the first parasitic element have multiple resonances by electro magnetic coupling.

Abstract: An antenna comprises a ground plate which is planar; a first power feed element which is disposed separately from the ground plate by a prescribed distance and which is formed in a prescribed shape; a first parasitic element which is planar and which is formed in a prescribed shape; a first shortcircuit part which electrically connects the first parasitic element and the ground plate; and a power feed part which is electrically connected with the first power feed element, wherein the first power feed element and the first parasitic element are disposed in parallel in part with each other, and the first power feed element and the first parasitic element have multiple resonances by electro magnetic coupling.

Abstract: Disclosed is a multiple-resonant surface-mounted antenna used for a radio device for mobile communication in a microwave band. A high frequency and a low frequency patch antenna electrodes are arranged apart from each other on one main surface of a dielectric block and a feeding line electrode is electromagnetically connected to the respective patch antenna electrodes. Each feeding line electrode is connected to each feeding terminal electrode and connected to each input/output line in every frequency band of a substrate, thereby realizing the multiple-resonant surface-mounted antenna capable of coping with two frequency bands.

Abstract: Disclosed is a multiple-resonant surface-mounted antenna used for a radio device for mobile communication in a microwave band. A high frequency and a low frequency patch antenna electrodes are arranged apart from each other on one main surface of a dielectric block and a feeding line electrode is electromagnetically connected to the respective patch antenna electrodes. Each feeding line electrode is connected to each feeding terminal electrode and connected to each input/output line in every frequency band of a substrate, thereby realizing the multiple-resonant surface-mounted antenna capable of coping with two frequency bands.

Abstract: A hemispherical dielectric resonator is arranged on a metal substrate to make a flat surface of the hemispherical dielectric resonator contact with the metal substrate, and a dielectric wave-guiding channel is connected with a curved side surface of the hemispherical dielectric resonator. Therefore, a dielectric resonance antenna in which the hemispherical dielectric resonator and the dielectric wave-guiding channel are placed on the same metal substrate is obtained. A signal transmitting through the dielectric wave-guiding channel is fed in the hemispherical dielectric resonator, the hemispherical dielectric resonator is resonated, and an electromagnetic wave is radiated. Therefore, the dielectric resonance antenna functions as a wave radiation device.

Abstract: A hemispherical dielectric resonator is arranged on a conductive substrate with a flat surface of the resonator in contact with the conductive substrate and fixed by a pair of fixing blocks. The dielectric resonator is fed with a signal feeder at a position at one side of the resonator such that intensity of the electric field is higher at that position. The fixing blocks contact a portion of the dielectric resonator where the intensity of the electric field is of a local minimum.

Abstract: A hemispherical dielectric resonator is arranged on a metal substrate to make a flat surface of the hemispherical dielectric resonator contact with the metal substrate, and a dielectric wave-guiding channel is connected with a curved side surface of the hemispherical dielectric resonator. Therefore, a dielectric resonance antenna in which the hemispherical dielectric resonator and the dielectric wave-guiding channel are placed on the same metal substrate is obtained. A signal transmitting through the dielectric wave-guiding channel is fed in the hemispherical dielectric resonator, the hemispherical dielectric resonator is resonated, and an electromagnetic wave is radiated. Therefore, the dielectric resonance antenna functions as a wave radiation device.

Abstract: A hemispherical dielectric resonator is arranged on a metal substrate to make a flat surface of the hemispherical dielectric resonator contact with the metal substrate, and a dielectric wave-guiding channel is connected with a curved side surface of the hemispherical dielectric resonator. Therefore, a dielectric resonance antenna in which the hemispherical dielectric resonator and the dielectric wave-guiding channel are placed on the same metal substrate is obtained. A signal transmitting through the dielectric wave-guiding channel is fed in the hemispherical dielectric resonator, the hemispherical dielectric resonator is resonated, and an electromagnetic wave is radiated. Therefore, the dielectric resonance antenna functions as a wave radiation device.

Abstract: A hemispherical dielectric resonator is arranged on a metal substrate to make a flat surface of the hemispherical dielectric resonator contact with the metal substrate, and a dielectric wave-guiding channel is connected with a curved side surface of the hemispherical dielectric resonator. Therefore, a dielectric resonance antenna in which the hemispherical dielectric resonator and the dielectric wave-guiding channel are placed on the same metal substrate is obtained. A signal transmitting through the dielectric wave-guiding channel is fed in the hemispherical dielectric resonator, the hemispherical dielectric resonator is resonated, and an electromagnetic wave is radiated. Therefore, the dielectric resonance antenna functions as a wave radiation device.

Abstract: In a mobile communication system, each base station is provided with an array antenna, a section for estimating the respective directions of one or more mobile stations with which the base station is in communication, based on estimated incoming directions of radio waves received from these mobile stations, and sections for operating on respective signals of the antenna elements constituting the array antenna such as to shape the radiation pattern of the antenna to form peaks of directivity which are oriented in the estimated directions of these mobile stations, and can include a capability for shaping these peaks in accordance with estimated positions of these mobile stations, thereby minimizing interference between transmissions from that base station and communication being executed between other adjacent stations of the system, and minimizing the number of different transmission frequencies required in the overall system.

Abstract: A plurality of antennas are disposed in a predetermined area and wherein size, configuration and mounting condition of the antennas are set so that their directivities formed by interference therebetween are most desirable.

Abstract: A first mobile unit identification system having a interrogator and responder. The interrogator transmits a given magnitude of a spread spectrum coded signal in standby mode. The responder receives the spread spectrum coded signal and when the magnitude of received signal exceeds a given value, it reflects the transmitted spread spectrum coded signal with ID code when the magnitude of received signal exceeds the given value. The interrogator receives this and then, transmits data to the responder with amplitude modulating the spread spectrum coded signal with the data. The responder detects by amplitude demodulation and stores the detected data. The interrogator may transmit a mode change code. The responder may transmit an end code after transmission of a data train. A second interrogator informs the responder of the standby mode thereof by amplitude-modulated signal having a given cycle.

Abstract: A mobile unit identifying system comprises: an interrogator having: a spread spectrum signal generation circuit for generating a spread spectrum coding signal using a predetermined pseudo noise signal; and a transmitting antenna for transmitting the spread spectrum coding signal; and a responder having: a memory for storing data; and a modulation unit for modulating radio signals including the transmitted spread spectrum coding signal with the data, the interrogator further comprising: a receiving antenna for receiving the modulated radio signals; and a mixer for mixing the received radio signals with the spread spectrum signal to detect the data. The responder has one or two antennas for receiving or reflecting the spread spectrum coding signal with modulation using a predetermined data. Phase adjusting circuits may be provided in both interrogator and responder to distinguished from reflected waves from reflective objects other than the responder.

Abstract: A digital analog converter which is especially suitable for use in converting a digital audio signal into an analog audio signal includes a unit pulse response signal generator for successively generating unit pulse response signals at a predetermined time interval, a digital data generator for generating digital data at the predetermined time interval, a multiplier for multiplying a unit pulse response signal generated at a certain time by a predetermined item of the digital data, and a mixer for producing an analog signal output by combining the unit pulse response signals that have been multiplied by the digital data.