Abstract: An antenna unit includes an antenna formed on a magnetic sheet. A transmission circuit includes an inductor, a matching capacitor, and the antenna connected in series, and a reception circuit includes the antenna, the matching capacitor, a resistor, and a capacitor connected in series. The antenna is formed as one turn, and the size of the antenna and the resistor involves a predetermined relationship.

Abstract: An antenna apparatus includes a base member that has an antenna unit and a loop pattern. The loop pattern is wound in such a manner that a magnetic field of the loop pattern is generated along the same direction as that of the antenna unit. Additionally, the loop pattern is formed by a plurality of loops connected parallel to each other.

Abstract: Provided is a RFID magnetic sheet to be attached to an IC tag. The RFID magnetic sheet is provided with a plurality of stripe arranged layers (11a, 11b) whereupon a plurality of magnetic stripes (12) composed of a metal magnetic material are arranged at intervals, and a resin film (10) interposed between the respective stripe arranged layers. The arrangement relationship between the stripe arranged layers is set so that the magnetic stripes on each of the stripe arranged layers intersect with the magnetic stripes on the other stripe arranged layer in a planar shape.

Abstract: An antenna unit includes an antenna formed on a magnetic sheet. A transmission circuit includes an inductor, a matching capacitor, and the antenna connected in series, and a reception circuit includes the antenna, the matching capacitor, a resistor, and a capacitor connected in series. The antenna is formed as one turn, and the size of the antenna and the resistor involves a predetermined relationship.

Abstract: An antenna apparatus is featured by that a base member 4 has an antenna unit 3 and a loop pattern 2 wound in such a manner that a magnetic field of the loop pattern 2 is generated along the same direction as that of the antenna unit 2, and the loop pattern 2 has been formed by a plurality of loops connected parallel to each other.

Abstract: An electronic component of the invention has: a substrate; first to third terminal portions disposed on the substrate; and at least one spiral conductor portion disposed between the first and second terminal portions. The third terminal portion is not electrically connected to other portions of the substrate, and the first and second terminal portions are electrically connected to or disconnected from each other. In the electronic component, the number of production steps is smaller, the cost is lower, and a more highly accurate inductor component is realized as compared with a laminated electronic component in which emphasis is put on increase of the capacitor component. It is possible to realize an electronic component having accurate band- or low-pass filter characteristics.

Abstract: An electronic component of the invention has: a substrate; first to third terminal portions disposed on the substrate; and at least one spiral conductor portion disposed between the first and second terminal portions. The third terminal portion is not electrically connected to other portions of the substrate, and the first and second terminal portions are electrically connected to or disconnected from each other. In the electronic component, the number of production steps is smaller, the cost is lower, and a more highly accurate inductor component is realized as compared with a laminated electronic component in which emphasis is put on increase of the capacitor component. It is possible to realize an electronic component having accurate band- or low-pass filter characteristics.

Abstract: A filter includes a substrate with a relative dielectric constant of 200 or less and a thickness of 0.1 mm or more. A first electrode is disposed on at least one surface of the substrate, a group of second electrodes is disposed on at least the other surface of the substrate. Each of the second electrodes is not in contact with each other and is not in contact with the first electrode. The filter also includes a chip type inductance element. The chip type inductance element has an inductance ranging from 0.1 nH to 30 nH and has dimensions of L1 in length, L2 in width and L3 in height, which satisfy the following conditions; 0.3 mm<L1<2.1 mm 0.1 mm<L2<1.1 mm 0.1 mm<L3<1.1 mm.

Abstract: An electronic component which comprises a substrate, conductive film on the surface of the substrate, a groove created on the conductive film, a protective material covering the groove, and terminals and on both ends of the substrate. Lengths P1 to P8 of the terminals and, the surface roughness and materials of the terminals and, and configuration of the protective material are specified for providing an electronic component and radio terminal with at least one of improved productivity, mountability, and characteristics.

Abstract: An inductance element providing a high Q factor even with a dawn-sized configuration comprises a column shape body (7), a coil (13) wound around the body (7), a terminal electrode provided at both ends of the body (7), connected with the coil (13), and a protection material (16) for covering the coil (13), which has a relative dielectric constant not higher than 6.0.

Abstract: A filter of the present invention comprises a substrate with a relative dielectric constant of 200 or less and thickness of 0.1 mm or more, a first electrode disposed on at least one surface of the substrate, a group of second electrode disposed on at least the other surface of the substrate, each of the group of second electrodes being not in contact with each other and also being not in contact with the first electrode, and a chip type inductance element. The chip type inductance element has an inductance ranging from 0.1 nH to 30 nH and has dimensions of L1 in length, L2 in width and L3 in height, which satisfy the following conditions.

Abstract: A filter device for a transmitter-receiver antenna includes a transmission side filter having resonators and a reception side filter having resonators. Each of the transmission side resonators has a first characteristic impedance ratio other than one. On the other hand, each of the reception side resonators has a second characteristic impedance ratio being set to a value which prevents spurious resonance of the reception side filter at an integral multiple of a fundamental resonance frequency of the transmission side filter, so as to avoid the situation where spurious components increase at the above-noted integral multiple in a frequency characteristic of the transmission side filter being affected by a frequency characteristic of the reception side filter.

Abstract: A dielectric filter including a plurality of coaxial type dielectric resonators having outer conductors and inner conductors is arranged so that the outer conductors are connected to each other. Also included in the dielectric filter are central conductors arranged to be brought into contact with the inner conductors of said plurality of coaxial type dielectric resonators and a dielectric substrate having thereon a plurality of substrate conductors whose number at least corresponds to the number of the plurality of coaxial type dielectric resonators, and input/output terminals provided on said dielectric substrate. The central conductors are respectively coupled to the substrate conductors provided on the dielectric substrate and inductance elements are connected to the substrate conductors which are positioned at both sides.

Abstract: A coaxial dielectric resonator for use at high frequency. The outer or inner peripheral surface of a tubular dielectric member is stepped so as to provide a greater suppression of spurious resonance. The dielectric member has a prism-shaped outer configuration so as to provide a high Q value, as well as improved space factor.