摘要:
A dielectric antenna of the present invention includes a pillar-shaped dielectric section for radiating an electromagnetic wave being fed thereto. The dielectric section includes a depressed portion in an upper portion thereof. The vertical cross section of the depressed portion has such a shape that the height of the dielectric section gradually increases toward the side surface of the dielectric section. For example, the depressed portion is a notch having a V-shaped vertical cross section. Alternatively, the depressed portion includes a flat surface portion.
摘要:
A dielectric loaded antenna apparatus has a column-shaped loaded dielectric which is loaded on an end portion of a feeding line of the dielectric loaded antenna apparatus. The loaded dielectric has an inclined radiation surface which is inclined from a surface perpendicular to an axial direction of the loaded dielectric. A cross section of the loaded dielectric perpendicular to the axial direction of the loaded dielectric has a shape of one of a circle, ellipse and polygon. The feeding line is a waveguide which includes a radiation waveguide and a feeding waveguide. The radiation waveguide has an axis parallel to the axial direction of the loaded dielectric and includes an opening for feeding an electromagnetic wave to the loaded dielectric. The feeding waveguide feeds the electromagnetic wave to the radiation waveguide.
摘要:
A traveling-wave combining array antenna apparatus includes first and second traveling-wave array antennas. The first traveling-wave array antenna has a plurality of antenna elements provided at intervals along a first feeder line, and has a radiating directivity characteristic. The second traveling-wave array antenna has a plurality of antenna elements provided at intervals along a second feeder line, and has a main beam of a half-value width and a radiating directivity characteristic of a side lobe level lower than that of the first traveling-wave array antenna. A transmitting signal is split into two signals, feeding the signals to the first and second traveling-wave array antennas, which are provided so that a variation of main-beam radiating angle of electromagnetic wave of transmitting signal radiated from the first traveling-wave array antenna corresponding to a frequency change, and that of the second traveling-wave array antenna are substantially canceled by each other.
摘要:
A dielectric antenna of the present invention includes a pillar-shaped dielectric section for radiating an electromagnetic wave being fed thereto. The dielectric section includes a depressed portion in an upper portion thereof. The vertical cross section of the depressed portion has such a shape that the height of the dielectric section gradually increases toward the side surface of the dielectric section. For example, the depressed portion is a notch having a V-shaped vertical cross section. Alternatively, the depressed portion includes a flat surface portion.
摘要:
A traveling-wave combining array antenna apparatus includes first and second traveling-wave array antennas. The first traveling-wave array antenna has a plurality of antenna elements provided at intervals along a first feeder line, and has a radiating directivity characteristic. The second traveling-wave array antenna has a plurality of antenna elements provided at intervals along a second feeder line, and has a main beam of a half-value width and a radiating directivity characteristic of a side lobe level lower than that of the first traveling-wave array antenna. A transmitting signal is split into two signals, feeding the signals to the first and second traveling-wave array antennas, which are provided so that a variation of main-beam radiating angle of electromagnetic wave of transmitting signal radiated from the first traveling-wave array antenna corresponding to a frequency change, and that of the second traveling-wave array antenna are substantially canceled by each other.
摘要:
A radiation imaging apparatus is provided. The apparatus has moving means moving a pair of an X-ray tube and a detector relatively to an object. The apparatus further has means which acquire digital frame data outputted from the detector. The frame data are acquired from the same portion being imaged of the same object at different time points. The apparatus has means which use the frame data to produce a plurality of three-dimensional optimally focused images at the respective time points, an actual position and shape of the portion being imaged being reflected in the images, and means which estimate changes of the plural three-dimensional optimally focused images.
摘要:
A radio communication device of the present invention comprises a first antenna, a second antenna, a phase varying section which varies a phase of a first RF signal received by or transmitted from the first antenna, and a phase control means which causes the phase varying section to vary a phase amount which is a varied amount of the phase of the first RF signal received by or transmitted from the first antenna. Thus, it is possible to prevent that a size of a device configuration increases and avoid that a reception electric field level is lowered in a localized area.
摘要:
Four antenna units arranged adjacent to each other are respectively connected to switches, and are connected to load impedance elements via the switches, or connected to an output terminal and a comparator via a switch. Another ends of the load impedance elements are grounded. The comparator judges which antenna unit receives a radio signal having the maximum signal level among the antenna units. A controller controls the switches and the switch so that the antenna unit that receives the radio communication signal having the maximum signal level is connected to the output terminal and the other antenna units are connected to the load impedance elements.
摘要:
In case of performing so-called “PET acquisition”, a nuclear medical diagnosis apparatus according to the present invention does not set only gamma rays which imparted predetermined energy values (for example, energy values of and above a Compton edge), as subjects for coincidental counting acquisition (coincidence acquisition), but it discriminates also further gamma rays which caused a photoelectric effect after having undergone Compton scattering once in a radiation detection unit, so as to set them as subjects for the coincidental counting acquisition. Concretely, if the added value of energy values observed in two detection elements is “near 511 keV”, the existence of the further gamma ray is presumed, and the acquisition thereof is possible. Besides, that one of the two detection elements as to which energy near the Compton edge is observed can be specified as the incident position of the gamma ray on the radiation detection unit.
摘要:
In an apparatus for measuring a specific absorption rate (SAR) for use in a radio apparatus, a first near magnetic field of a radio wave radiated from a reference radio apparatus is measured in free space, and an SAR of the radio wave radiated from the reference radio apparatus by using a predetermined phantom according to a predetermined measurement method. A transformation factor α is calculated by dividing the measured SAR by a square value of the measured first near magnetic field, and a second near magnetic field of a radio wave radiated from a radio apparatus to be measured is measured in free space. Then an SAR of the radio wave radiated from the radio apparatus to be measured is estimated and calculated by multiplying a square value of the measured second near magnetic field by the calculated transformation factor α.