摘要:
An antenna device of an embodiment includes: an antenna having a feeding point and an end portion apart from the feeding point, the end portion being an open end; a variable impedance matching circuit connected to the antenna at the feeding point; a probe placed in such a position that the distance from the end portion to a tip of the probe is equal to or shorter than one eighth of the wavelength corresponding to the maximum radio frequency used in the antenna device; and a controller that is connected to the probe, and controls the variable impedance matching circuit, based on an electrical signal measured with the probe.
摘要:
A radio apparatus according to one aspect of the embodiments includes a substrate configured to have a high-frequency circuit formed thereon. The high-frequency circuit includes an electromagnetic wave radiation source to radiate an electromagnetic wave. The radio apparatus also includes a shielding case configured to house the substrate and have a plurality of openings each having a length of half a wavelength of the electromagnetic wave in a direction orthogonal to a polarization of the electromagnetic wave. Each of the openings is provided to make each distance between centers of the openings to be shorter than one wavelength of the electromagnetic wave.
摘要:
A reader that performs wireless communication with a tag inside a metal housing including a plurality of metal walls, the reader has an antenna which transmits and receives electromagnetic wave, a transmission control device that writes and/or reads information to/from the tag via the antenna, and a reflecting plate, reflecting the electromagnetic wave, and having a reflection phase different from that of the metal wall.
摘要:
A wireless power transmission device that supplies power to a power receiving device including a second self-resonant coil having a winding structure in which a conductive wire is wound one turn or more perpendicularly to a second central axis, the wireless power transmission device comprising: a first self-resonant coil having the winding structure in which the conductive wire is wound one turn or more perpendicularly to a first central axis to supply the power to the second self-resonant coil that is not located on the first central axis; and a third self-resonant coil having the winding structure in which the conductive wire is wound one turn or more perpendicularly to a third central axis that is not perpendicular to the first central axis and arranged on the first central axis.
摘要:
A measurement apparatus includes an anechoic chamber, a DUT board, rotation units, and a feeding arm. The anechoic chamber has inner-walls. Each inner-wall is covered with a radio wave absorber. One of the inner-wall is a first wall with an aperture and the other inner-walls are second walls. The DUT board holds a first antenna to be measured with radiation property and a probe to detect a signal from the first antenna. A part of the DUT board is inserted into the anechoic chamber through the aperture opened in the first wall. One end of the feeding arm holds a second antenna radiating a radio wave to the first antenna in the anechoic chamber. Each rotation unit provides on each second wall and is selectively attached to the other end of the feeding arm for rotating the second antenna and for feeding to the second antenna.
摘要:
In this second radio channel setting example, the grouping is done for each radio mobile stations 98 running on the same lane. A different radio channel is assigned to each group. Accordingly, this prevents the beam patterns using the same channel from intersecting with each other (interfering with each other). Actually, as shown in FIG. 10B, the pas or the pursuit does not occur between the radio mobile stations 98. Thus, the same radio channel is assigned to each radio mobile stations 98 running on the same lane so as to avoid the interference in the same radio channel. Hence, the same radio channel can be repeatedly used.
摘要:
This is a radio communication system having a radio base station controller 20 which is connected to a plurality of base stations 10n−1, 10n and 10n+1, and then assigns a fixed channel to each of radio mobile stations 18a, 18b and 18c, and further controls the beam patterns of the radio base stations 10n−1, 10n and 10n+1, and accordingly carries out the radio communications with the radio mobile stations 18a, 18b and 18c. The radio base station controller 20, when transmitting to and receiving from the different radio mobile stations 18a, 18b and 18c to which the same channel is assigned, controls the beam patterns so that the channels do not interfere with each other.
摘要翻译:这是具有连接到多个基站10 n -1,10 n和10 n + 1的无线基站控制器20的无线通信系统,然后向每个无线移动台18a分配固定信道, 18b和18c,并且进一步控制无线电基站10 n -1,10 n和10 n +1的波束图案,并且相应地执行与无线电移动台18a,18b和18c的无线电通信 。 无线电基站控制器20在向与其分配相同信道的不同无线电移动站18a,18b和18c进行发送和接收时,控制波束图案,使得信道彼此不干扰。
摘要:
A transformer between a waveguide and a transmission-line includes a high-frequency circuit module, transmission-lines, a waveguide, and feed pins. The high-frequency circuit module has differential-pair terminals to input and output a differential signal. The transmission-lines are connected to the differential-pair terminals. The waveguide includes first to third metal walls. The feed pins are connected to the transmission-lines inside of the waveguide. The feed pins have a first distance of approximately (λg/2) from each other. One of the feed pins has a second distance of approximately (λg*(1+2α)/4) from the third metal plane. “λg” is a wavelength in the waveguide and “α” is an integer which is equal or larger than “0”. Each of the feed pins has a third distance of approximately (a/2) from the first or second wall. “a” is length of the waveguide along the third metal wall.
摘要:
A measurement apparatus includes an anechoic chamber, a DUT board, rotation units, and a feeding arm. The anechoic chamber has inner-walls. Each inner-wall is covered with a radio wave absorber. One of the inner-wall is a first wall with an aperture and the other inner-walls are second walls. The DUT board holds a first antenna to be measured with radiation property and a probe to detect a signal from the first antenna. A part of the DUT board is inserted into the anechoic chamber through the aperture opened in the first wall. One end of the feeding arm holds a second antenna radiating a radio wave to the first antenna in the anechoic chamber. Each rotation unit provides on each second wall and is selectively attached to the other end of the feeding arm for rotating the second antenna and for feeding to the second antenna.
摘要:
A transmitter transmits both an electric power signal and an information signal. The electric power signal includes a first frequency. The information signal includes a second frequency different from the first frequency.