Abstract: The object of the invention is to provide a thermal conductivity measuring device that comprises a heat generator arranged in such a way as to come into contact with an object to be measured for thermal conductivity, a heat resistant material arranged in such a way as to come into contact with the heat generator, at least one pair of differential thermocouples for measuring a voltage value caused by the difference in temperature of two points of the heat resistant material, the temperature being generated by allowing heat to flow from the heat generator, and a calculating device for calculating the time rate of change of output voltage of the differential thermocouples and then calculating the thermal conductivity of the object to be measured on the basis of the calculated time rate of change.

Abstract: The object of the invention is to provide a thermal conductivity measuring device that comprises a heat generator arranged in such a way as to come into contact with an object to be measured for thermal conductivity, a heat resistant material arranged in such a way as to come into contact with the heat generator, at least one pair of differential thermocouples for measuring a voltage value caused by the difference in temperature of two points of the heat resistant material, the temperature being generated by allowing heat to flow from the heat generator, and a calculating device for calculating the time rate of change of output voltage of the differential thermocouples and then calculating the thermal conductivity of the object to be measured on the basis of the calculated time rate of change.

Abstract: There are disposed four antenna elements which are arranged circumferentially at regular intervals, and four 90-degree hybrids each having four terminals, two 90-degree hybrids which are arranged in parallel are connected in two stages, only one of the output terminals of an upstream 90-degree hybrid and only one of the input terminal of a downstream 90-degree hybrid cross each other and are connected to each other, and the four output terminals of the two downstream 90-degree hybrids and the four antenna elements are connected to each other; the passing phase between the terminals that cross each other within the respective 90-degree hybrids is set to 0 degree, and the passing phase between the terminals that are in parallel within the respective 90-degree hybrids is set to 90 degrees. As a result, the structure of the feed circuit can be simplified, and plural kinds of beams can be formed.

Abstract: An antenna apparatus arranged in accordance with the invention has a plurality of element antennas 1 arranged on a plurality of concentric circles 2 assumed to exist on a plane and differs in radius from each other, and forms a beam in a direction inclined by &thgr;0 at the maximum from a direction perpendicular to the plane. If the radius of the n-th concentric circle 2 from the inner side is an; the number of element antennas 1 arranged on the n-th concentric circle 2 from the inner side is Mn, and the number of waves is k, the number Mn of element antennas 1 arranged on each concentric circle 2 is determined so as to satisfy the following equation: Mn+0.8·Mn1/3>k·an·(1+sin &thgr;0) Also, the element antennas 1 are arranged on each concentric circle 2 by being generally equally spaced apart from each other in the circumferential direction of the concentric circle.

Abstract: A directivity control of an adaptive antenna is performed for an antenna of a base station when a signal is received in the antenna of the base station, and the directivity control of the adaptive antenna is performed for an antenna of a mobile station when a signal is received in the antenna of the mobile station. Therefore, even though an antenna of a second mobile station functions as an interference wave source, the reception of an interference wave from the interference wave source can be prevented in both the antenna of the base station and the antenna of the mobile station, and a communication quality in both the base station and the mobile station can be maintained in the communication between the base station and the mobile station.

Abstract: A plurality of concentric circle array antennas each having a different radius are disposed on an identical plane, and a plurality of element antennas are arranged circumferentially in each of the concentric circle array antennas. The plurality of concentric circle array antennas are arranged at regular intervals d in most part thereof, and the concentric circle array antennas corresponding to a remaining part of the plurality of concentric circle array antennas are arranged at intervals d±0.4 to 0.6d. The radii of the part of plural concentric circles change by ±(0.4 to 0.6)d, so that it is possible to reduce a wide-angle side lobe.

Abstract: There are disposed four antenna elements which are arranged circumferentially at regular intervals, and four 90-degree hybrids each having four terminals, two 90-degree hybrids which are arranged in parallel are connected in two stages, only one of the output terminals of an upstream 90-degree hybrid and only one of the input terminal of a downstream 90-degree hybrid cross each other and are connected to each other, and the four output terminals of the two downstream 90-degree hybrids and the four antenna elements are connected to each other; the passing phase between the terminals that cross each other within the respective 90-degree hybrids is set to 0 degree, and the passing phase between the terminals that are in parallel within the respective 90-degree hybrids is set to 90 degrees. As a result, the structure of the feed circuit can be simplified, and plural kinds of beams can be formed.

Abstract: A plurality of concentric circle array antennas each having a different radius are disposed on an identical plane, and a plurality of element antennas are arranged circumferentially in each of the concentric circle array antennas. The plurality of concentric circle array antennas are arranged at regular intervals d in most part thereof, and the concentric circle array antennas corresponding to a remaining part of the plurality of concentric circle array antennas are arranged at intervals d±0.4 to 0.6 d.

Abstract: A directivity control of an adaptive antenna is performed for an antenna of a base station when a signal is received in the antenna of the base station, and the directivity control of the adaptive antenna is performed for an antenna of a mobile station when a signal is received in the antenna of the mobile station. Therefore, even though an antenna of a second mobile station functions as an interference wave source, the reception of an interference wave from the interference wave source can be prevented in both the antenna of the base station and the antenna of the mobile station, and a communication quality in both the base station and the mobile station can be maintained in the communication between the base station and the mobile station.

Abstract: Since adaptive control has been made by using different reference characters every transmitter-receiver, it has been necessary to provide an adaptive control device every transmitter-receiver. Hereupon, an adaptive array antenna apparatus according to the invention provides a weighting control device for calculating a weight coefficient to control weighting processing so that electric power of array signals synthesized by applying weighting processing to signals received by antennas of a plurality of systems becomes minimum, and an adaptive control device for using the weight coefficient for application of weighting processing to thereby form null points of antenna directivity in a direction, along which interference signals having a greater electric power than that of desired signals arrive, to remove the interference signals and to output array signals to transmitter-receivers.

Abstract: When the portable wireless device of the present invention is used, the second housing 3 with the antenna unit 4 telescopically received therein is turned about the hinge 2 to a spread position where the antenna unit 4 is spread out a sufficient distance away from the housing 1 and is extended from the second housing 3. Hence, during communication the antenna unit 4 is kept sufficiently far apart from the user's head 100 to provide improved transmission and/or reception characteristics.

Abstract: A composite antenna apparatus comprising a balun connected to an inner conductor at the upper end of a coaxial line 11, one end of a helical element formed by a pair of wire conductors is connected to the balun, the other end is wound symmetrically around the coaxial line using the the coaxial line as a center so as to face the balun and is connected to the outer conductor 13 at the lower end of the coaxial line. The provision of an outer conductor connecting terminal connected to the outer conductor and an inner conductor connecting terminal connected to the inner conductor at the lower end of the coaxial line, allows the formation, on the same axis, of a helical antenna fed by the coaxial line via the helical element and a monopole antenna formed by the outer conductor of the coaxial line. Thereby equivalent gain in the horizontal plane and a reduction in the occupied volume is achieved.

Abstract: An object of the present invention is to provide an antenna feeding circuit, which requires no balance-unbalance converter and has a simplified structure. The object is attained, by an antenna feeding circuit, according to the present invention, in which micro-strips lines are constituted from one or more pair(s) of band conductors (5a, 5b) disposed on the outer surface of the cylindrical body (1) and an inner conductor (6) disposed on the whole of the inner surface of the cylindrical body (1). A 180 degree distributor (2) supplies electric power to the band conductors (5a, 5b) so that the phase difference between the currents in the band conductors (5a, 5b) is 180 degrees. Inutile current induced in the inner surface of the inner conductor can be cancelled out, because the inner conductor 6 is disposed on the whole of the inner surface of the cylindrical body (1).

Abstract: An antenna apparatus for a portable telephone which is capable of having a better gain characteristic and also capable of achieving a better circularly polarized characteristic over a wide range is provided.

Abstract: A mobile satellite communication system including an artificial satellite which is situated in a satellite orbit and develops an active phased array antenna so as to accomplish a line to a terrestrial station using a portable terminal in a specific area. As a result, a service that satisfies a demand for communication in the specific area can be realized.

Abstract: A non-driven first linear element is disposed in the vicinity of an inverted-F second linear antenna element. The driven second linear element is disposed over a conductive plate having a flat shape, in such a manner as to be substantially parallel to the inverted-F antenna. The non-driven element has a short-circuited end of the inverted-F antenna, and has substantially the same resonant frequency as that of the inverted-F antenna.

Abstract: In an apparatus and method for controlling an array antenna comprising a plurality of antenna elements arranged so as to be adjacent to each other in a predetermined arrangement configuration, a plurality of received signals received by the antenna elements is transformed into respective pairs of quadrature baseband signals, using a common local oscillation signal, wherein each pair of quadrature baseband signals is orthogonal to each other. Then predetermined first and second data are calculated based on each pair of transformed quadrature baseband signals, and are filtered using a noise suppressing filter. Respective elements of a transformation matrix for in-phase combining are calculated based on the filtered first and second data, and the received signals obtained from the each two antenna elements are put in phase based on the calculated transformation matrix. Thereafter, a plurality of received signals which are put in phase are combined in phase, and an in-phase combined received signal is outputted.

Abstract: In an apparatus for adaptively controlling an array antenna of M antenna elements, a multi-beam forming circuit calculates N beam field strengths in a known manner, and a beam selecting circuit selectively outputs beam field strengths not smaller than a predetermined threshold value by comparing the N beam field strengths with the threshold value. At least two adaptive control processors calculate N weight coefficients corresponding to N beams according to a constant modulus algorithm, respectively multiplies the calculated beam field strengths by the calculated N weight coefficients, and combines in phase respective signals of multiplication results, outputting the combined signal as a reception signal. In an initial state of one adaptive control processor, a weight coefficient thereof corresponding to the maximum beam field strength is set to a predetermined initial value not zero, and weight coefficients corresponding to the other beam field strengths are set to zero.

Abstract: In an apparatus and method for controlling an array antenna including a predetermined plurality of M antenna elements arranged in a predetermined arrangement configuration, beam electric field strengths of a plurality of N beams of transmitting signals are calculated, and then signals representing the calculated beam electric field strengths equal to or larger than a threshold value are outputted. Thereafter, based on the outputted signals, there are calculated a plurality of N weight coefficients for the receiving signals respectively corresponding to the plurality of N beams of transmitting signals, such that a main beam of the array antenna is directed toward an incoming direction of a desired radio wave and also a level of the receiving signal in an incoming direction of an unnecessary radio wave are made zero.

Abstract: Disclosed herein is an antenna system comprising a plurality of element antennas, a plurality of variable phase shifters and a plurality of variable amplitude type devices connected to the plurality of element antennas respectively, and an arithmetic unit used to perform the arithmetical operation of the excitation amplitude and phase for exciting each of the plurality of element antennas. The arithmetic unit includes the four means and performs the arithmetical operation of the excitation amplitude and phase used to define a desired radiation pattern composed by each of the element antennas with respect to a preset allowable variation width D of the excitation amplitude.