Abstract: A mobile telephone device includes a display casing having display panels and a television antenna unit, an operation casing having an operation unit and a mobile telephone device antenna unit, and a hinge unit for rotatably connecting the display casing to the operation casing. The television antenna unit is provided at the end of the display casing opposite the end having the hinge unit. The mobile telephone device antenna unit is provided at the end of the operation casing on the hinge unit side. Therefore, the antennas are always separated by the length of the display casing. In addition, a ground electrode is formed so as to continuously extend on the display casing and the operation casing. One end of the television antenna unit electrically communicates with this ground electrode. Thus, a ground electrode having a length corresponding to the television antenna unit can be provided.

Abstract: A multi-resonant antenna device includes an antenna element and an LC parallel resonance circuit making the antenna element resonate in a plurality of frequency bands, and the LC parallel resonance circuit includes a T-type circuit or PI-type circuit including an inductance element, acting as a shunt element, and capacitance elements, which prevent the impedance from becoming infinite in a certain frequency band. In this way, a drop, that is, a notch portion, in the frequency characteristic causing deterioration of the gain can be eliminated.

Abstract: A multi-resonant antenna device of the present invention contains an antenna element 22 and an LC parallel resonance circuit 31 making the antenna element 22 resonate in a plurality of frequency bands, and the LC parallel resonance circuit 31 contains a T-type circuit or PI-type circuit composed of an inductance element 26, acting as a shunt element, and capacitance elements 29 and 30, which prevents the impedance from becoming infinite in a certain frequency band. In this way, a drop, that is, a notch portion, in the frequency characteristic causing deterioration of the gain can be eliminated.

Abstract: A portable terminal device including a main body including a data entry keyboard; a cover openably and closably attached to the main body and establishing a connecting portion between the main body and the cover; a display disposed on the inner side of the cover; a chip antenna disposed on the cover at a place other than the display and opposed to the connecting portion; the chip antenna including a ceramic base body, a conductor disposed at least either inside the base body or on a surface thereof, and a feeding terminal disposed on a surface of the base body and connected to one end of the conductor. The above portable terminal device has the directivity of an antenna in a desired direction without increasing the size and weight of the portable terminal device and without having a bulky and/or separate and/or protruding antenna device.

Abstract: A chip antenna comprising a basic body made of a ceramic material; a first conductor and a second conductor respectively disposed at least either inside or on the surface of the basic body so as to be close to each other; a feeding terminal for applying a voltage to the first conductor disposed on the surface of the basic body and connected to the first conductor; and a grounding terminal disposed on the surface of the basic body and connected to the second conductor.

Abstract: The invention provides a chip antenna comprising: a substrate made by laminating a plurality of sheet layers made of ceramic; a radiating conductor having substantially planar shape and provided on said substrate; a grounding conductor having substantially planar shape and provided so as to oppose said radiating conductor with said sheet layers interposed in between; a capacitor conductor having substantially planar shape and provided so as to oppose said radiating conductor and said grounding conductor with said sheet layers interposed in between; a first shorting conductor which connects said radiating conductor and said grounding conductor; a second shorting conductor which connects said grounding conductor and said capacitor conductor; a feed terminal connected to said radiating conductor or said capacitor conductor; and a ground terminal connected to said grounding conductor. According to the above a chip antenna, the resonance frequency can be adjusted readily with compact size can be achieved.

Abstract: A chip antenna 10 includes, inside a rectangular-parallelepiped base 11 having barium oxide, aluminum oxide, and silica as main constituents, a conductor 12 wound in a spiral form along the length direction of the base 11, and an LC parallel resonance circuit 13, which is inserted in the intermediate portion of the conductor 12 and which is connected electrically in series with the conductor 12, and includes, on the surface of the base 11, a power-feeding terminal 14 for applying a voltage to the conductor 12. The conductor 12 is separated into a first conductor 121 and a second conductor 122 by the LC parallel resonance circuit 13. The LC parallel resonance circuit 13 is formed of a coil L1, which is an inductance element, and a capacitor C1, which is a capacitance element, which are connected in parallel.