摘要:
An antenna apparatus includes an antenna element and a parasitic element provided on a first surface of a dielectric substrate, and an antenna element and a parasitic element provided on a second surface of the dielectric substrate. Each of the parasitic elements is provided at a position away from the antenna elements by a distance of one-fourth of an operating wavelength λ in communication.
摘要:
An antenna apparatus includes an antenna element and a parasitic element provided on a first surface of a dielectric substrate, and an antenna element and a parasitic element provided on a second surface of the dielectric substrate. Each of the parasitic elements is provided at a position away from the antenna elements by a distance of one-fourth of an operating wavelength λ in communication.
摘要:
When a variable directivity antenna apparatus is controlled to form an initial composite directional pattern, RSSI is measured, and a weak electric field group or an intense electric field group is selected based on the measured RSSI. When the variable directivity antenna apparatus is controlled to form the composite directional patterns included in the selected composite directional pattern group, PER for each of the composite directional patterns is measured, and one composite directional pattern is selected from among the composite directional patterns included in the selected composite directional pattern group based on the measured PER, so that the variable directivity antenna apparatus is controlled to form the selected composite directional pattern.
摘要:
A wireless communications apparatus (1) in the present invention transmits, via wireless communications, data recorded on a memory unit (13) to a recording apparatus (2). The wireless communications apparatus (1) includes: a communication area determining unit (19) determining whether or not the wireless communications apparatus (1) is in a communication area having a threshold value equal to MIDDLE or higher; a stillness detecting unit (15) detecting whether or not the wireless communications apparatus (1) remains still; and a wireless communications unit (17) starting to transmit, via the wireless communications, the data recorded on the memory unit (13) to the recording apparatus (2) in the case where (i) the communication area determining unit (19) determines that the wireless communications apparatus (1) is in the communication area having the threshold value equal to MIDDLE or higher, and (ii) the stillness detecting unit (15) detects that the wireless communications apparatus (1) remains still.
摘要:
An antenna unit is provided with: steerable antennas, each having one active antenna element and two parasitic antenna element; and metal blocks. Each of the active antenna elements is associated with at least one of the metal blocks such that the metal block is disposed remote from the active antenna element by a predetermined distance and operates as a reflector for the active antenna element. Each of the parasitic antenna elements is provided with a switching circuit for changing an electrical length of the parasitic antenna element, and the parasitic antenna element operates as a reflector for an active antenna element of the same steerable antenna as the parasitic antenna element by changing the electrical length using the switching circuit.
摘要:
An antenna unit is provided with: steerable antennas, each having one active antenna element and two parasitic antenna element; and metal blocks. Each of the active antenna elements is associated with at least one of the metal blocks such that the metal block is disposed remote from the active antenna element by a predetermined distance and operates as a reflector for the active antenna element. Each of the parasitic antenna elements is provided with a switching circuit for changing an electrical length of the parasitic antenna element, and the parasitic antenna element operates as a reflector for an active antenna element of the same steerable antenna as the parasitic antenna element by changing the electrical length using the switching circuit.
摘要:
A steerable antenna includes an radiating antenna element and parasitic antenna elements. Each of the parasitic antenna elements is provided with a pair of PIN diodes. On each of control lines connecting the PIN diodes to a controller, inductors are provided at predetermined intervals on portions of the control line electromagnetically coupled to another steerable antenna. The intervals for providing the inductors is set to such a length that substantially no resonance occurs in a section of the control line between the inductors at an operating frequency of the steerable antenna.
摘要:
A plurality of directional patterns are classified into groups and stored in a directional pattern memory, such that among the plurality of directional patterns, the directional patterns strongly correlated with each other are classified into the same group, while the directional patterns weakly correlated with each other are classified into the different groups. One directional pattern is selected from each group in the directional pattern memory. One directional pattern is determined from the selected directional patterns, in accordance with a communication quality of signals each received when each one of the selected directional patterns is set for steerable antenna element. The determined directional pattern is set for the steerable antenna element.
摘要:
A variable directivity antenna apparatus is configured to include a parasitic element, a plurality of antenna elements each provided to be away from the parasitic element by an electrical length of a quarter-wavelength, and a PIN diode connected to the parasitic element and changing over whether or not to ground the parasitic element. A radiation pattern from the variable directivity antenna apparatus is changed by outputting a control signal for changing over whether or not the parasitic element operates as a parasitic element by selectively turning on or off the PIN diode.
摘要:
Before start of streaming, a server apparatus obtains from client apparatuses their respective numbers of antenna combinations, determines a training time t1 according to the maximum of the numbers of antenna combinations, and notifies the client apparatuses of the training time t1. Each client apparatus determines a training time t2 required to estimate transmission path conditions for one antenna combination, based on the training time t1. The server apparatus transmits a training signal during the training time t1. Each client apparatus estimates transmission path conditions using the training signal during the training time t2 for each antenna combination, and selects and sets an antenna combination based on the estimated transmission path conditions.