Abstract: A multi-resonant antenna having three independent resonance characteristics for three frequency bands includes a first electrode having an open end formed on the top surface of a dielectric substrate of a rectangular plate shape so as to extend from a feeding portion in a first direction (e.g., counterclockwise) along the periphery of the rectangular area; a second electrode having an open end and extending from the feeding portion in a second direction (e.g., clockwise) along the periphery of the rectangular area; and a third electrode positioned such that an open end of the third electrode is closer to the open end of the first electrode than to the open end of the second electrode, and such that the open end of the third electrode is closer to the open end of the first electrode than to a midsection (i.e., half the length) of the first electrode in the longitudinal direction thereof.

Abstract: A chip antenna and an antenna apparatus, which allow the resonance frequency of the antenna to be set with a high degree of freedom, include a feeding electrode formed on the bottom surface, fourth side surface, and top surface of a dielectric substrate, a non-feeding electrode formed on the bottom surface, third side surface, and top surface of the dielectric substrate, wherein the leading ends of the feeding electrode and the non-feeding electrode are facing each other with a predetermined distance therebetween on the top surface of the dielectric substrate. The chip antenna and antenna apparatus further include a frequency adjusting electrode formed on the first side surface of the dielectric substrate, and ground electrodes connected to ground electrodes of a circuit substrate on which the chip antenna is mounted, wherein the ground electrodes are electrically connected to the frequency adjusting electrode and are formed on the bottom surface of the dielectric substrate.

Abstract: This disclosure provides a chip antenna and an antenna device including the chip antenna. The chip antenna is not likely to be affected by a ground electrode located lower than the chip antenna when the chip antenna is mounted on a circuit board, and can have resulting small frequency variation and small reduction in gain. The chip antenna includes a dielectric substrate having a bottom face, a top face, a first side face, a second side face, a third side face, and a fourth side face. A non-feeding electrode extends from the fourth side face to the top face, another non-feeding electrode extends from the third side face to the top face. An end of the non-feeding electrode and an end of the non-feeding electrode face each other on the top face with a certain space therebetween. The bottom face includes bottom-face electrodes electrically connected to the non-feeding electrodes and a bottom-face electrode electrically connected to a feeding electrode.

Abstract: A chip antenna and an antenna apparatus, which allow the resonance frequency of the antenna to be set with a high degree of freedom, include a feeding electrode formed on the bottom surface, fourth side surface, and top surface of a dielectric substrate, a non-feeding electrode formed on the bottom surface, third side surface, and top surface of the dielectric substrate, wherein the leading ends of the feeding electrode and the non-feeding electrode are facing each other with a predetermined distance therebetween on the top surface of the dielectric substrate. The chip antenna and antenna apparatus further include a frequency adjusting electrode formed on the first side surface of the dielectric substrate, and ground electrodes connected to ground electrodes of a circuit substrate on which the chip antenna is mounted, wherein the ground electrodes are electrically connected to the frequency adjusting electrode and are formed on the bottom surface of the dielectric substrate.

Abstract: A multi-resonant antenna having three independent resonance characteristics for three frequency bands includes a first electrode having an open end formed on the top surface of a dielectric substrate of a rectangular plate shape so as to extend from a feeding portion in a first direction (e.g., counterclockwise) along the periphery of the rectangular area; a second electrode having an open end and extending from the feeding portion in a second direction (e.g., clockwise) along the periphery of the rectangular area; and a third electrode positioned such that an open end of the third electrode is closer to the open end of the first electrode than to the open end of the second electrode, and such that the open end of the third electrode is closer to the open end of the first electrode than to a midsection (i.e., half the length) of the first electrode in the longitudinal direction thereof.

Abstract: An antenna structure includes a capacitance-rendering portion located between an open end portion of a feed radiation electrode and a ground portion. A switch for changing the capacitance between the open end portion of the feed radiation electrode and the ground portion rendered by the capacitance-rendering portion is provided. When the capacitance between the open end portion of the feed radiation electrode and the ground portion is increased by the capacitance-rendering portion, a resonant frequency in the fundamental frequency band, caused by the antenna operation of the feed radiation electrode, is reduced corresponding to the increased amount of the capacitance. When the capacitance between the open end portion of the feed radiation electrode and the ground portion is decreased by the changing operation of the capacitance-rendering portion, the resonant frequency in the fundamental frequency band is increased corresponding to the decreased amount of the capacitance.

Abstract: An antenna structure includes a capacitance-rendering portion located between an open end portion of a feed radiation electrode and a ground portion. A switch for changing the capacitance between the open end portion of the feed radiation electrode and the ground portion rendered by the capacitance-rendering portion is provided. When the capacitance between the open end portion of the feed radiation electrode and the ground portion is increased by the capacitance-rendering portion, a resonant frequency in the fundamental frequency band, caused by the antenna operation of the feed radiation electrode, is reduced corresponding to the increased amount of the capacitance. When the capacitance between the open end portion of the feed radiation electrode and the ground portion is decreased by the changing operation of the capacitance-rendering portion, the resonant frequency in the fundamental frequency band is increased corresponding to the decreased amount of the capacitance.

Abstract: In order to enable one radiant electrode to transmit and receive signals with a plurality of frequency bands, in a base member, a feeding electrode to be connected to a signal supply source and an open electrode floated from the ground are arranged adjacent to each other leaving a space. In the base member, one end of a linear electrode is connected to the feeding electrode while the other end is connected to the open electrode. A substantially loop-shaped radiant electrode extending from the feeding electrode toward the open electrode via the linear electrode is defined by the feeding electrode, the open electrode, and the linear electrode. The linear electrode is provided with a short-cut electrode short-cutting a loop of the radiant electrode.

Abstract: In order to enable one radiant electrode to transmit and receive signals with a plurality of frequency bands, in a base member, a feeding electrode to be connected to a signal supply source and an open electrode floated from the ground are arranged adjacent to each other leaving a space. In the base member, one end of a linear electrode is connected to the feeding electrode while the other end is connected to the open electrode. A substantially loop-shaped radiant electrode extending from the feeding electrode toward the open electrode via the linear electrode is defined by the feeding electrode, the open electrode, and the linear electrode. The linear electrode is provided with a short-cut electrode short-cutting a loop of the radiant electrode.

Abstract: A reduced thickness radio unit without deteriorating antenna performance is disclosed. A metallic plate performing radio wave transmission/reception together with the radiation electrode, is conductively connected to the radiation electrode of a surface-mount type antenna. The metallic plate is preferably disposed so as to be opposed to the outer long-side surface of the substrate of the surface-mount type antenna with a space therebetween. Therefore, when mounting the metallic metal on a circuit board of the radio unit, the metallic plate does not face the circuit board surface and the top surface of a shield case, which are equivalent to ground. By thus disposing the metallic plate substantially perpendicularly to the circuit board, the problem of increase in electrostatic capacitance between the metallic plate and ground can be avoided, the increase in electrostatic capacitance being due to the reduction in thickness of the radio unit.

Abstract: A reduced thickness radio unit without deteriorating antenna performance is disclosed. A metallic plate performing radio wave transmission/reception together with the radiation electrode, is conductively connected to the radiation electrode of a surface-mount type antenna. The metallic plate is preferably disposed so as to be opposed to the outer long-side surface of the substrate of the surface-mount type antenna with a space therebetween. Therefore, when mounting the metallic metal on a circuit board of the radio unit, the metallic plate does not face the circuit board surface and the top surface of a shield case, which are equivalent to ground. By thus disposing the metallic plate substantially perpendicularly to the circuit board, the problem of increase in electrostatic capacitance between the metallic plate and ground can be avoided, the increase in electrostatic capacitance being due to the reduction in thickness of the radio unit.

Abstract: The invention provides an electronic part comprising an electronic-part body comprising: composite-material body made of synthetic resin in which ceramic powder as a functional material and a catalytic agent to make plating practicable are dispersed; and a layer of composite material of synthetic resin in which ceramic powder as a functional material is dispersed, said layer covering the external surface of said composite-material body except the portion in which an electrode is to be disposed; and an electrode disposed on the external surface of said electronic-part body. The above described electronic part is excellent in the freedom of shape, high in dimensional accuracy, and it is easy to realize the intended electrical characteristics.

Abstract: A rectangular-prism-shaped base member is made from a dielectric material or a magnetic material. A ground electrode and a power supplying electrode are formed on one end face of the base member with a gap disposed therebetween. At least one through hole is formed between the end face and the opposing end face. A radiation electrode is formed on the inside surface of the through hole. One end of the radiation electrode is connected to the ground electrode, and the other end serves as an open end. The power supplying electrode and the radiation electrode are electromagnetically coupled through a capacitor formed at the gap.

Abstract: A surface mounting antenna in which a wider frequency bandwidth can be achieved and a dual-frequency signal can be obtained without hampering the gain and needing to enlarge the configuration of the antenna. Also disclosed is a communication apparatus using this type of antenna. Two radiation electrodes for producing different resonant frequencies and a feeding electrode are formed on the obverse surface of a substrate formed of a dielectric material or a magnetic material. A ground electrode is primarily disposed on the reverse surface of the substrate. The radiation electrodes form open ends and are connected at the other ends to the ground electrode. The open ends of the radiation electrodes and the feeding electrode are electromagnetically coupled to each other through capacitances generated in gaps formed between the feeding electrode and the open ends.

Abstract: A compact surface-mount antenna is constructed from a rectangular-prism-shaped base member made from a dielectric material or a magnetic material. A through-hole is formed between one end-face and the opposing end-face in the base member. A radiation electrode is formed on the inside surface of the through-hole. One end of the radiation electrode is connected to a ground electrode formed on the one end-face, and the other end of the radiation electrode serves as an open end on the opposite end-face. A power-supplying electrode is formed through a dielectric gap disposed around the open end on the opposite end-face.

Abstract: A surface-mount-type antenna that is capable of being surface-mounted on a printed circuit board includes a dielectric substrate, a through-hole formed within the dielectric substrate and having its openings in opposed side surfaces of the dielectric substrate, a radiation electrode formed in the inner periphery of the through-hole, a feeding electrode, and side electrodes formed on the side surfaces in which the through-hole has its openings. The antenna can be placed on a printed circuit board having an electrode pattern, and the feeding electrode and the electrode pattern can be soldered together to thereby surface-mount the antenna on the printed circuit board.

Abstract: A dielectric rod antenna including a dielectric rod, a ring-shaped conductive film provided on an outer peripheral surface of the dielectric rod, and a waveguide. The conductive film is provided on an outer peripheral surface portion of the dielectric rod which is inclined from a base end portion toward a forward end portion. The conductive film is arranged to intersect the waveguide so as to form a substantially V-shaped cross-sectional area.