摘要:
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. In an initial state of the other adaptive control processor, a weight coefficient of the other adaptive control processor corresponding to at least a beam field strength having the second greater level is set to the initial value, and weight coefficients corresponding to the other beam field strengths is set to zero.
摘要:
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.
摘要:
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).
摘要:
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.
摘要:
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.
摘要:
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. This antenna apparatus is comprised of: a first cylinder 4 provided in such a manner that the first cylinder is uprighted on an upper portion 1 of a housing of the portable telephone; 4-element dipole array antennas 4a to 4d connected to a transmitter/receiver circuit built in the housing via a feeding line path, and arranged on the surface of the first cylinder in an equiinterval in such a manner that the 4-element dipole array antennas have inclined angles with respect to a central axis of the first cylinder, an element length of the 4-element dipole array antennas being equal to an approximately 1/2 electromagnetic wavelength; a second cylinder 5 having a diameter smaller than an inner diameter of the first cylinder, and arranged in such a manner that the second cylinder can be stored into the first cylinder, and when the second cylinder is drawn from the first cylinder, the second cylinder is uprighted in the vicinity of an upper space of the first cylinder in a coaxial manner; and 4-element line-shaped conductors 5a to 5d arranged on the surface of the second cylinder in an equiinterval in such a manner that the 4-element line-shaped conductors have inclined angles with respect to a central axis of the second cylinder.
摘要:
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. Further, based on the calculated plurality of N weight coefficients and a transmitting frequency of the transmitting signals, there is calculated at least either one of a plurality of M amounts of phase shift and a plurality of M amounts of amplitudes for the transmitting signals, and then the antenna elements are controlled in accordance with at least one of the calculated amplitude and phase data, thereby radiating the controlled transmitting signals therefrom.
摘要:
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.
摘要:
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.
摘要:
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.