Abstract: According to one embodiment, a spiral antenna includes an antenna element, a cavity, and a radio wave absorber. The spiral antenna is formed into a spiral shape on a dielectric substrate. The cavity is formed to have a space with the antenna element. The radio wave absorber is placed to cover a terminal end portion of the spiral.

Abstract: An aspect of an antenna apparatus according to the present invention is provided with a conductor plate, radiating elements disposed to face the conductor plate and partially short-circuited to the conductor plate, a feeding terminal provided on the conductor plate, and a feeding path connecting the feeding terminal and a feeding portion of the radiating elements to each other.

Abstract: In an antenna apparatus, a radiation element includes a perturbation element. A first power feeding line has a first end connected to the radiation element and is configured to feed power to the radiation element. A second power feeding line has a first end configured to feed power to the radiation element through electromagnetic coupling. The radiation element, the first power feeding line and the second power feeding line are arranged on a same plane to constitute a balance type antenna.

Abstract: A wideband antenna including a ground element, and an antenna body provided on the ground element with a predetermined distance. The antenna body includes a feed element and a dielectric substrate, wherein an annular passive element is provided on the top surface of the dielectric substrate with a predetermined gap from the feed element. A plural short-circuit pins are equally spaced on the outer periphery of the passive element, whereby the passive element and the ground element 17 are connected by the short-circuit pins. A slit is formed on the passive element in the vicinity of the short-circuit pins. Since the slit is formed on the passive element, a resonance circuit having a resonance frequency dependant on the shape of the slit is formed on the passive element in the vicinity of the slit, whereby the radiation of the frequency component from the feed element is prevented.

Abstract: According to one embodiment, a spiral antenna includes an antenna element, a cavity, and a radio wave absorber. The spiral antenna is formed into a spiral shape on a dielectric substrate. The cavity is formed to have a space with the antenna element. The radio wave absorber is placed to cover a terminal end portion of the spiral.

Abstract: The problem of the present invention is to offer a wave absorber that has reflection attenuation capability sufficient to enable prevention of communication disturbances due to reflection and the like of EM waves, that enables greater thinness and lighter weight, and that has wide-band attenuation properties, as well as a manufacturing method of the wave absorber. The wave absorber of the present invention has a structure which sequentially laminates a grid-like conductor layer composed of an electric conductor, a first dielectric layer, a high-resistance conductor layer having a surface resistivity within a prescribed range, a second dielectric layer, and a pattern layer having multiple patterns composed of an electric conductor, wherein each pattern in said pattern layer differs in either or both of size and form relative to another adjacent pattern.

Abstract: A wave absorber of the present invention includes a sequentially laminated structure including an conductor layer (11) made of a conductive material; a first dielectric layer (polycarbonate substrate (12) and bismaleimide-triazine substrate (13)) made of one layer or a multilayer of a dielectric material; and a patterned layer (14) including a plurality of a pattern made of the conductive material, wherein the conductor layer, the first dielectric layer, and the patterned layer are laminated sequentially, and each pattern in the patterned layer (14) is different from other adjacent patterns with respect to at least one of size and shape. Therefore, the wave absorber has sufficient reflection-attenuating capability to prevent communication failure caused by a reflection of a radio wave and so on, can be thin-sized and reduced in weight, and has a wide-band attenuation property.

Abstract: An antenna device includes a plurality of loop elements. The loop elements are made of conductive material, and constitute a planar antenna element having N-fold rotationally symmetric shape with respect to a center portion of the planar antenna element, the N being an integer of three or more. Each of the loop elements includes at least two first elements extending in a first direction parallel to a radial direction of the planar antenna element and at least one second element extending in a circumferential direction of the planar antenna element. A ground plate is made of conductive material and opposes the planar antenna element. A power feeding line extends from the ground plate to the planar antenna element, and is electrically connected to the planar antenna element at the center portion.

Abstract: An antenna apparatus, including: an antenna device including a feeding point and a pair of antenna elements placed symmetrically with respect to the feeding point; and a parasitic device placed parallel to each of the antenna elements of the antenna device and including one or a plurality of elements placed at a position separated from each of the antenna elements, wherein the element of the parasitic device includes a gap at a center of the element in an extending direction and includes a pair of sub-elements structured symmetrically with respect to the gap as a boundary.

Abstract: In an antenna apparatus, a radiation element includes a perturbation element. A first power feeding line has a first end connected to the radiation element and is configured to feed power to the radiation element. A second power feeding line has a first end configured to feed power to the radiation element through electromagnetic coupling. The radiation element, the first power feeding line and the second power feeding line are arranged on a same plane to constitute a balance type antenna.

Abstract: An aspect of an antenna apparatus according to the present invention is provided with a conductor plate, radiating elements disposed to face the conductor plate and partially short-circuited to the conductor plate, a feeding terminal provided on the conductor plate, and a feeding path connecting the feeding terminal and a feeding portion of the radiating elements to each other.

Abstract: To provide a thin wideband antenna unit capable of shrinking the size of a radiation element in a case where a dielectric is not used. In a wideband antenna unit 10 having a ground plate 12 and a flat shaped radiation element 14 disposed on a plane (x, y) flush with a plane where the ground plate extends, the radiation element 14 has an elliptically shape. The radiation element 14 and the ground plate 12 are apart from each other by a predetermined feeding distance ?FD. A ratio between an outside diameter 2aout in an ellipse's x-direction and an outside diameter 2bout in an ellipse's y-direction is 8:5. The elliptically shaped radiation element 14 has an elliptically shaped opening 14a which is concentric O with the elliptically shape. An inside diameter 2bin in the ellipse's y-direction is half of an outside diameter 2bout in the ellipse's y-direction.

Abstract: To provide a circularly polarized antenna capable of obtaining an excellent axial ratio over a very wide range and having a great gain in a zenith direction. The circularly polarized antenna (10) includes a planar loop antenna element (122) and feeding means for providing quadruple feeds with their phases varied by 90 degrees with respect to the planar loop antenna element (122). The feeding means has four feeding probes (131 through 134). The circularly polarized antenna (10) is provided with a circuit board (25) disposed in parallel with the planar loop antenna element (122). The circuit board (25) has an area greater than that of the planar loop antenna element (122). The circuit board (25) has a principal surface (25U) which entirely serves as a ground plane. The circuit board (25) has a rear surface (25L) provided with a 90-degree phase shifter formed thereon.

Abstract: An antenna unit consists of an EBG reflector, a single curl antenna supported at a central portion of the EBG reflector, and a periodic structure upper plate disposed apart from a principal surface of the EBG reflector by a predetermined distance. The EBG reflector includes a substrate having the principal surface and (Nx×Ny) square patches which are printed on the principle surface of the substrate and which are arranged in a matrix fashion (lattice structure). The periodic structure upper plate consists of a film and (Nx×Ny) square patch-like conductors printed on the film. The (Nx×Ny) square patch-like conductors are disposed so as to oppose to the (Nx×Ny) square patches, respectively.

Abstract: The problem of the present invention is to offer a wave absorber that has reflection attenuation capability sufficient to enable prevention of communication disturbances due to reflection and the like of EM waves, that enables greater thinness and lighter weight, and that has wide-band attenuation properties, as well as a manufacturing method of the wave absorber. The wave absorber of the present invention has a structure which sequentially laminates a grid-like conductor layer composed of an electric conductor, a first dielectric layer, a high-resistance conductor layer having a surface resistivity within a prescribed range, a second dielectric layer, and a pattern layer having multiple patterns composed of an electric conductor, wherein each pattern in said pattern layer differs in either or both of size and form relative to another adjacent pattern.

Abstract: A wave absorber of the present invention includes a sequentially laminated structure including an conductor layer (11) made of a conductive material; a first dielectric layer (polycarbonate substrate (12) and bismaleimide-triazine substrate (13)) made of one layer or a multilayer of a dielectric material; and a patterned layer (14) including a plurality of a pattern made of the conductive material, wherein the conductor layer, the first dielectric layer, and the patterned layer are laminated sequentially, and each pattern in the patterned layer (14) is different from other adjacent patterns with respect to at least one of size and shape. Therefore, the wave absorber has sufficient reflection-attenuating capability to prevent communication failure caused by a reflection of a radio wave and so on, can be thin-sized and reduced in weight, and has a wide-band attenuation property.

Abstract: In a broadband antenna unit having a ground plate and an elliptically shaped radiation element disposed at an upper portion of the ground plate in a plane where the ground plate extends, the ground plate has a semi-elliptically shaped upper edge and a lower portion where both side corner portions are deleted with a central portion left. The ground plate and the radiation element are formed on a substrate.

Abstract: An antenna unit consists of an EBG reflector, a single curl antenna supported at a central portion of the EBG reflector, and a periodic structure upper plate disposed apart from a principal surface of the EBG reflector by a predetermined distance. The EBG reflector includes a substrate having the principal surface and (Nx×Ny) square patches which are printed on the principle surface of the substrate and which are arranged in a matrix fashion (lattice structure). The periodic structure upper plate consists of a film and (Nx×Ny) square patch-like conductors printed on the film. The (Nx×Ny) square patch-like conductors are disposed so as to oppose to the (Nx×Ny) square patches, respectively.

Abstract: To provide a compact and light broad range antenna apparatus transmitting and receiving an electric wave in GHz frequency band (wavelength: ?), a flat shaped antenna element (10), where a length b? in an X-axis direction is less than ?/4 and a length a? in a Y-axis direction is less than ?/4, is arranged at a distance j less than ?/4 from a ground plate (2) in the Y-axis direction and connected to a high-frequency power source (9), and an enlarged flat shaped parasitic element (15) is structured by connecting a base portion (13) having approximately the same shape and dimension as those of the antenna element (10) with an extension portion (14) extending from the base portion (13) in the X-axis direction so as to face to the antenna element (10) with a distance, and connected conductively with the ground plate (2) by a ground line (5).

Abstract: In a UWB antenna having an upper dielectric member, a lower dielectric member, and a conductor pattern interposed therebetween, the conductor pattern has a feeding point at a generally center portion of a front surface of the antenna. The conductor pattern further has an inverted triangular portion including a right tapered portion and a left tapered portion extending from the feeding point towards right and left side surfaces of the antenna, respectively. A main expanding portion expands from an upper side of the inverted triangular portion. A right expanding portion and a left expanding portion expand from the right and the left tapered portions of the inverted triangular portion, respectively.