摘要:
An antenna device comprising a plurality of directional antennas which are aligned on the same axis in one direction and which are also arranged in a manner that the main radiation directions of the plurality of directional antennas deviate from each other in a direction orthogonal to the direction. Hence, a drop in directivity due to the array factor can be prevented and radiation characteristics in the plane orthogonal to the direction is expanded.
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 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 dual-band multilayer bandpass filter having a first filter unit (18) for filtering a first signal having a first frequency and a second filter unit (19) for filtering a second signal having a second frequency. First and second filter units are arranged in stacked ceramic layers. A first blocking element (20a, 20b; 25a, 25b; 25a', 25b'; 46a, 46b) is coupled to the first filter unit (18) for blocking the second signal from being applied to the first filter unit (18). A second blocking element (21a, 21b; 26a, 26b; 25c, 25d; 27a, 27b) is coupled to the second filter unit (19) for blocking the first signal from being applied to the second filter unit (19).
摘要:
A voltage-controlled resonator is fabricated by laminating, one on top of the other, a first dielectric which has a resonant circuit and on the upper surface of which a variable-capacitance element is mounted, and a second dielectric which has a through-hole formed in a position thereof corresponding to the position of the variable-capacitance element and which has a dual function of shielding and resonant frequency tuning. With this structure, the height of the resonator can be further reduced compared with the prior art while retaining the shielding effect, and moreover, further precise resonant frequency tuning can be accomplished as compared with the prior art.
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:
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.