Abstract: In an impedance matching circuit, first to fourth inductors are formed by a conductor pattern of a coil shape, and a fifth inductor is formed by a conductor pattern of an unwound shape. The first inductor and the third inductor are respectively formed in different layers of a substrate and are arranged in such a relationship as to have coil openings overlapping each other. Moreover, the second inductor and the fourth inductor are respectively formed in different layers of the substrate and are arranged in such a relationship as to have coil openings overlapping each other. Two coils interposing the mounting position of the RFIC are in a 180° rotational symmetry relationship.

Abstract: A filter that includes a series circuit of a first Zener diode and a second Zener diode, a third Zener diode connected between a node and ground, and a third inductor. A first series resonant circuit is formed by a parasitic capacitance of the first Zener diode, a parasitic capacitance of the third Zener diode, and the third inductor, and a second series resonant circuit is formed by a parasitic capacitance of the second Zener diode, the parasitic capacitance of the third Zener diode, and the third inductor. Moreover, the parasitic capacitances of the first Zener diode and the second Zener diode are substantially equal, and the parasitic capacitance of the third Zener diode is larger than the parasitic capacitance of each of the first Zener diode and the second Zener diode.

Abstract: An RFID tag is provided that includes an RFIC chip having a first connection terminal and a second connection terminal, a first electrode electrically connected to the first connection terminal of the RFIC chip, a capacitance element connected in series to the first electrode and the RFIC chip, and short-circuit parts connecting the first electrode and a ground at an intermediate position of an electrical length of the first electrode. Moreover, the electrical length of the first electrode is a half of a wavelength of a communication frequency of the RFIC chip, the first connection terminal of the RFIC chip is connected to the first electrode at a position within one third of the electrical length from an end portion of the first electrode, and the second connection terminal of the RFIC chip is connected to the ground.

Abstract: An ESD protection device that includes a semiconductor substrate that has a first main surface, terminal electrodes formed on the first main surface, a terminal electrode that is connected to the ground, and a wiring electrode that connects the terminal electrodes to each other and that forms a part of a main line. Moreover, the semiconductor substrate has a rectangular cuboid shape in a plan view and further includes a first semiconductor region that is connected to the wiring electrode, a second semiconductor region that is connected to the third terminal electrode, and a third semiconductor region. The first semiconductor region and the second semiconductor region are arranged along short sides of the semiconductor substrate and electrically connected to each other with the third semiconductor region that extends along the short sides interposed therebetween.

Abstract: An RFID tag is provided that transmits and receives a communication signal. The RFID tag includes a base material, antenna patterns provided on the base material, an RFIC package that is a feeding circuit connected to the antenna patterns, and an ignition protection member provided on the base material or the antenna patterns. Moreover, the ignition protection member contains moisture, such that ignition and combustion can be prevented even in a situation where the RFID tag is subjected to high-frequency power for heating a food item while attached to the food item or the like.

Abstract: An RFIC module is provided that includes a first planar conductor and a second planar conductor that faces each other. Moreover, an inductor is provided of which both ends are connected between the first planar conductor and the second planar conductor. An RFIC also has both ends connected between the first planar conductor and the second planar conductor. In a plan view of the first planar conductor, the inductor is adjacent to a first point that is at an outer edge of the first planar conductor, and the RFIC is adjacent to a second point of the outer edges of the first planar conductor. In addition, the second point is positioned away from the first point.

Abstract: An RFID tag is provided that transmits and receives a communication signal. The RFID tag includes a base material, antenna patterns provided on the base material, an RFIC package that is a feeding circuit connected to the antenna patterns, and an ignition protection member provided on the base material or the antenna patterns. Moreover, the ignition protection member contains moisture, such that ignition and combustion can be prevented even in a situation where the RFID tag is subjected to high-frequency power for heating a food item while attached to the food item or the like.

Abstract: An RFID tag including an RFIC element, a first inductor element that includes a first insulating substrate having a mounting surface on which the RFIC element is mounted, and first coil-shaped antenna internally embedded in first insulating substrate with a winding axis perpendicular to the mounting surface, and second inductor element that includes second insulating substrate mounted on the mounting surface, and second coil-shaped antenna internally embedded in second insulating substrate, electrically connected to first coil-shaped antenna, and with a winding axis parallel to the mounting surface. The first insulating substrate includes a laminate with dielectric layers or magnetic layers laminated, and the first coil-shaped antenna includes a laminate coil-shaped antenna in which conductor patterns are each formed on a corresponding one of the layers of the laminate, such that they are connected to each other through interlayer connection conductor.

Abstract: An ESD protection element includes a semiconductor substrate, a wiring layer, and an inductor conductor. The semiconductor substrate includes a Zener diode. The inductor conductor is provided on the wiring layer and has a two-dimensional spiral shape. The inductor conductor includes a first inductor conductor and a second inductor conductor that are continuously provided from an outer peripheral end toward an inner peripheral end, and a connection conductor portion in a vicinity of a portion at which the first inductor conductor and the second inductor conductor are connected to each other. The second inductor conductor has a width smaller than a width of the first inductor conductor.

Abstract: A filter that includes a series circuit of a first Zener diode and a second Zener diode, a third Zener diode connected between a node and ground, and a third inductor. A first series resonant circuit is formed by a parasitic capacitance of the first Zener diode, a parasitic capacitance of the third Zener diode, and the third inductor, and a second series resonant circuit is formed by a parasitic capacitance of the second Zener diode, the parasitic capacitance of the third Zener diode, and the third inductor. Moreover, the parasitic capacitances of the first Zener diode and the second Zener diode are substantially equal, and the parasitic capacitance of the third Zener diode is larger than the parasitic capacitance of each of the first Zener diode and the second Zener diode.

Abstract: An ESD protection device that includes a semiconductor substrate that has a first main surface, terminal electrodes formed on the first main surface, a terminal electrode that is connected to the ground, and a wiring electrode that connects the terminal electrodes to each other and that forms a part of a main line. Moreover, the semiconductor substrate has a rectangular cuboid shape in a plan view and further includes a first semiconductor region that is connected to the wiring electrode, a second semiconductor region that is connected to the third terminal electrode, and a third semiconductor region. The first semiconductor region and the second semiconductor region are arranged along short sides of the semiconductor substrate and electrically connected to each other with the third semiconductor region that extends along the short sides interposed therebetween.

Abstract: A high-frequency transformer includes a primary coil and a secondary coil coupled to each other by magnetic field coupling and sharing a coil winding axis, a first terminal connected to a first end of the primary coil, a second terminal connected to a first end of the secondary coil, and a common terminal connected to a second end of the primary coil and a second end of the secondary coil. The primary and secondary coils are helical coils including loop conductor patterns, and the number of turns of a first loop conductor pattern closest to the second end of the primary coil is larger than an average number of turns of other loop conductor patterns included in the primary coil.

Abstract: An ESD protection device includes a first terminal and a second terminal defining a first balanced port, a third terminal and a fourth terminal defining a second balanced port, and a ground terminal. A first coil and a third coil are provided between the first terminal and the third terminal to cancel an inductance component of a first ESD protection circuit. A second coil and a fourth coil are provided between the second terminal and the fourth terminal to cancel an inductance component of a second ESD protection circuit.

Abstract: This disclosure provides an antenna apparatus in which stable antenna characteristics are maintained by detecting surrounding conditions that affect the antenna characteristics and appropriately compensating the antenna characteristics. More specifically, when surrounding condition such as a human body (e.g., a palm or fingers) approaches and enters an electric field of a pseudo dipole formed by an antenna element electrode, a stray capacitance is sensed and stable antenna characteristics are maintained by appropriately controlling an antenna matching circuit to compensate for a change in the antenna characteristics due to the approach of the surrounding condition.

Abstract: A thin film LC component includes a substrate that has a first surface and a second surface opposing to each other, a thin film capacitor that is formed on the first surface by a thin film process, a thin film inductor that is formed in a region of the second surface by a thin film process, the region at least partially overlapping the thin film capacitor when viewed in plan, interlayer connection conductors that are formed in the substrate and connect the thin film capacitor and the thin film inductor to each other, an insulating layer that is formed over the first surface and covers the thin film capacitor, and a plurality of terminal electrodes that are formed on a surface of the insulating layer and are connected to the thin film capacitor and the thin film inductor.

Abstract: A common mode choke coil includes a differential transmission line including first and second signal lines, a main circuit including a first coil provided in the first signal line, and a second coil provided in the second signal line and connected to the first coil by magnetic field coupling, and a parallel resonance circuit including a third coil connected to both the first and second coils by magnetic field coupling, and a first capacitor electrically connected in parallel to the third coil. In the common mode choke coil, a first resonant frequency of the main circuit is equal or substantially equal to a second resonant frequency of the parallel resonance circuit.

Abstract: A first coil of a common mode choke coil includes first and second loop-shaped conductors in different layers, and an interlayer connection conductor that connects the first and second loop-shaped conductors. The inner and outer diameters of the second loop-shaped conductor are less than or equal to the inner and outer diameters of the first loop-shaped conductor. A second coil includes third and fourth loop-shaped conductors in different layers, and an interlayer connection conductor that connects the third and fourth loop-shaped conductors. The third loop-shaped conductor is outside the first loop-shaped conductor in the same layer as the first loop-shaped conductor, and the fourth loop-shaped conductor is inside the second loop-shaped conductor in the same layer as the second loop-shaped conductor.

Abstract: A variable capacitance device includes a ferroelectric capacitor, a control terminal, a ground terminal, and a capacitor. The ferroelectric capacitor includes a ferroelectric film and capacitor electrodes sandwiching the ferroelectric film, and its capacitance value is changed according to a control voltage value applied between the capacitor electrodes. The control terminal is connected to a first end of the ferroelectric capacitor. The ground terminal is connected to a second end of the ferroelectric capacitor. The capacitor is connected between the control terminal and the ground terminal, and has a capacitance larger than that of the ferroelectric capacitor.

Abstract: An ESD protection device includes a first terminal and a second terminal defining a first balanced port, a third terminal and a fourth terminal defining a second balanced port, and a ground terminal. A first coil and a third coil are provided between the first terminal and the third terminal to cancel an inductance component of a first ESD protection circuit. A second coil and a fourth coil are provided between the second terminal and the fourth terminal to cancel an inductance component of a second ESD protection circuit.

Abstract: An impedance converting circuit module includes a first matching circuit, a feeding-circuit-side matching circuit interposed between the first matching circuit and a feeding circuit, and an antenna-side matching circuit interposed between the first matching circuit and a radiating element. The feeding-circuit-side matching circuit performs impedance matching between a feeding port of the feeding circuit and the first matching circuit, and the antenna-side matching circuit performs impedance matching between a port of the radiating element and the first matching circuit.