Abstract: A power converter includes a transformer including a transformer including a primary winding and a secondary winding magnetically coupled to the primary winding, a bridge circuit including a switching element, and an inductor. A direct current voltage is converted into an alternating current voltage by turning on and off the switching element in the bridge circuit. An output voltage in the secondary winding is induced by supplying the alternating current voltage to the primary winding. The inductor is disposed on a path connecting the switching element and the primary winding. A resonance inductance value Lr including a leakage inductance value of the transformer and an inductance value of the inductor satisfies Formula 1.

Abstract: A magnetic component includes a first winding and a second winding which is insulated from the first winding and magnetically couples with the first winding. The first winding forms a first coil unit by being wound. The second winding forms a second coil unit by being wound about the same axis as the first winding. The second winding forming the second coil unit is disposed in areas X and Z. The magnetic component has the first coil unit and the second coil unit at positions that satisfy Equations 1 and 3.

Abstract: Disclosed is a coil structure including: a first coil that is a first primary coil; a second coil that is a second primary coil; a first core around which the first coil is wound, the first core having an annular shape; a second core around which the second coil is wound, the second core having an annular shape; and a third coil that is a secondary coil, the first core including a first penetrating section that penetrates the third coil, the second core including a second penetrating section that penetrates the third coil, the first penetrating section being separated from the second penetrating section.

Abstract: A coil structure includes a conductor band and a first insulating plate. The conductor band turns around a coil axis in such a manner that the conductor band folds at a plurality of portions which form a plurality of folded portions. The first insulating plate includes a first edge portion which abuts along at least one of the plurality of folded portions. At least part of the conductor band is wound around the first insulating plate.

Abstract: A vibration power generator includes: a fixed substrate; a first fixed electrode piece disposed on the fixed substrate, the first fixed electrode piece having a first width of 2w; a second fixed electrode piece disposed on the fixed substrate, the second fixed electrode piece having a second width of 2w; a cover substrate disposed with a space g from the fixed substrate, the cover substrate being opposed to the fixed substrate; a vibrating body disposed between the fixed substrate and the cover substrate; and an electret electrode piece disposed on a side opposed to the first fixed electrode piece and the second fixed electrode piece of the vibrating body, the electret electrode piece having a width that is greater than 2w and less than or equal to 2w+s.

Abstract: A vibration power generator comprises: a fixed substrate; a vibrating body having a surface opposed to the fixed substrate, the vibrating body being vibratable to the fixed substrate; electret electrodes aligned in a vibration direction on one of the surface of the fixed substrate and the surface of the vibrating body; and first fixed electrodes and second fixed electrodes alternately aligned in the vibration direction on the other thereof, wherein when the vibrating body is at a resting position, each of the electret electrodes overlaps with both electrodes of a corresponding fixed electrode pair, the corresponding fixed electrode pair being one of the first fixed electrodes and one of the second fixed electrodes that are opposed to the electret electrode, and when the vibrating body is not at a resting position, each of the electret electrodes always overlaps with at least one electrode of the corresponding fixed electrode pair.

Abstract: A resonator using the MEMS technology is provided which improves the accuracy of a shape of electrodes so as avoid a short circuit that would otherwise be caused between input and output electrodes to thereby increase the reliability thereof. A resonator includes a substrate 101, an insulation layer 102 formed selectively on the substrate 101 as a sacrificial surface, a beam 103 formed on the substrate 101 via a space, a first support portion 104A formed on the insulation layer 102 of the same material as that of the beam 103, and electrodes formed with a space defined between the beam 103 and themselves for signals to be inputted thereinto and outputted therefrom. A sectional area of the beam 103 and a sectional area of the first support portion 104A are substantially equal in a section which is perpendicular to a longitudinal direction of the beam 103.

Abstract: There is provided a vibration power generator for converting vibration energy into electric power. The vibration power generator includes a fixed substrate, and a vibrator capable of vibrating with respect to the fixed substrate. Fixed electrode pieces are disposed on the fixed substrate, and electret electrode pieces opposed to the fixed electrode pieces are disposed on the vibrator. The vibration power generator is adapted to generate electricity, through changes in capacitances between the fixed electrode pieces and the electret electrode pieces, due to the vibration of the vibrator. The electret electrode pieces have opposite end portions in the vibration direction which have a higher average electric-charge density per unit area than that of middle portions, in the vibration direction, of the electret electrode pieces.

Abstract: A vibration power generator 110 including a first fixed substrate 111L, a second fixed substrate 111U, a movable substrate 112 which is vibratory relative to the first and second fixed substrates, a plurality of first electrodes 119a formed over the second fixed substrate, a plurality of second electrodes 119b formed on the movable substrate and opposed to the first electrodes, wherein one of the first electrode 119a and the second electrode 119b includes a film holding a charge, is fixed to a rotating body such that the first fixed substrate 111L, the second fixed substrate 111U and the movable substrate 112 are perpendicular to a radial direction of the rotating body and the first fixed substrate is disposed nearer to a rotational axis side of the rotating body.

Abstract: A MEMS oscillator having a feedback-type oscillation circuit including a MEMS resonator and an amplifier, a voltage control unit operable to control a bias voltage applied to an oscillating member of the MEMS resonator, and an auto gain control unit which receives an output from the amplifier and, based on a level of the output, to output an amplitude control signal for controlling a gain of the amplifier to the amplifier such that the level of the output from the amplifier comes to be a predetermined level, wherein the voltage control unit controls the bias voltage applied to the oscillating member based on an operating temperature of the MEMS resonator such that a peak gain of the MEMS resonator comes to have a predetermined value regardless of the operating temperature, and the voltage control unit derives the operating temperature of the MEMS resonator by monitoring the amplitude control signal.

Abstract: A MEMS oscillator including: an oscillator unit being capable of outputting an output from an amplifier as an original oscillator signal that includes a feedback type oscillator circuit including a MEMS resonator and an amplifier, and an automatic gain controller receiving the output from the amplifier and controlling a gain of the amplifier based on a level of the output to maintain a level of the output from the amplifier constant; and a corrector unit that receives the original oscillator signal, that generates from the original oscillator signal a signal of a predetermined set frequency, and that outputs the generated signal of the predetermined set frequency as an output signal.

Abstract: A MEMS resonator 100 including a substrate 112; an vibrator 102 including an mechanically vibrating part and a fixed part; at least one electrode 108 that is close to the vibrator and has an area overlapping with the vibrator across a gap 109 in a direction perpendicular to a surface of the substrate; and a pressure transferring mechanism to displace the at least one electrode according to an externally applied pressure so as to change the gap; is connected to a detection circuit that detects transmission characteristics of an AC signal from an input electrode to an output electrode, the input and output electrodes being one and the other of the vibrator 102 and the at least one electrode 108, and the pressure is detected based on the transmission characteristics of the AC signal that is detected by the detection circuit.

Abstract: A MEMS oscillator having a feedback-type oscillation circuit including a MEMS resonator and an amplifier, a voltage control unit operable to control a bias voltage applied to an oscillating member of the MEMS resonator, and an auto gain control unit which receives an output from the amplifier and, based on a level of the output, to output an amplitude control signal for controlling a gain of the amplifier to the amplifier such that the level of the output from the amplifier comes to be a predetermined level, wherein the voltage control unit controls the bias voltage applied to the oscillating member based on an operating temperature of the MEMS resonator such that a peak gain of the MEMS resonator comes to have a predetermined value regardless of the operating temperature, and the voltage control unit derives the operating temperature of the MEMS resonator by monitoring the amplitude control signal.

Abstract: A MEMS resonator 100 including a substrate 112; an vibrator 102 including an mechanically vibrating part and a fixed part; at least one electrode 108 that is close to the vibrator and has an area overlapping with the vibrator across a gap 109 in a direction perpendicular to a surface of the substrate; and a pressure transferring mechanism to displace the at least one electrode according to an externally applied pressure so as to change the gap; is connected to a detection circuit that detects transmission characteristics of an AC signal from an input electrode to an output electrode, the input and output electrodes being one and the other of the vibrator 102 and the at least one electrode 108, and the pressure is detected based on the transmission characteristics of the AC signal that is detected by the detection circuit.

Abstract: A digital television broadcast receiving section (100) of a mobile telephone terminal includes an antenna (101), a notch filter (102), a low-pass filter (LPF) (103), a low noise amplifier (LNA) (104), a receiving IC (105), a control section (107), and an input section (108). A passband for digital television broadcast is divided into several parts. The control section (107) switches a characteristic of each of the notch filter (102) and the LPF (103) so as to combine filters appropriate for a low-band channel or a high-band channel. Thus, frequencies in a mobile telephone transmission frequency band of the mobile telephone terminal, and frequencies in a band of other systems, the frequencies in these band being interfering waves, are largely attenuated, and at the same time, frequencies in the passband which is a frequency band for digital television broadcast are allowed to pass with low loss.

Abstract: A high frequency filter includes an inductor, a serial resonance circuit including an inductor and capacitors, a serial resonance circuit including an inductor and capacitors, and a varactor diode connected between a connection point between the capacitor and the capacitor and a connection point between the capacitor and the capacitor. A controller simultaneously changes two attenuation pole frequencies of the filter device by changing a capacitance of the varactor diode.

Abstract: A MEMS oscillator including: an oscillator unit being capable of outputting an output from an amplifier as an original oscillator signal that includes a feedback type oscillator circuit including a MEMS resonator and an amplifier, and an automatic gain controller receiving the output from the amplifier and controlling a gain of the amplifier based on a level of the output to maintain a level of the output from the amplifier constant; and a corrector unit that receives the original oscillator signal, that generates from the original oscillator signal a signal of a predetermined set frequency, and that outputs the generated signal of the predetermined set frequency as an output signal.

Abstract: A resonator using the MEMS technology is provided which improves the accuracy of a shape of electrodes so as avoid a short circuit that would otherwise be caused between input and output electrodes to thereby increase the reliability thereof. A resonator includes a substrate 101, an insulation layer 102 formed selectively on the substrate 101 as a sacrificial surface, a beam 103 formed on the substrate 101 via a space, a first support portion 104A formed on the insulation layer 102 of the same material as that of the beam 103, and electrodes formed with a space defined between the beam 103 and themselves for signals to be inputted thereinto and outputted therefrom. A sectional area of the beam 103 and a sectional area of the first support portion 104A are substantially equal in a section which is perpendicular to a longitudinal direction of the beam 103.

Abstract: A micromachine switch switches an electrical connection between signal electrodes in accordance with control signals. The micromachine switch includes a substrate, a rotating body provided on the substrate, and a movable electrode provided on the rotating body. The micromachine switch also includes a first signal electrode, one end of which is electrically connected to one end of the movable electrode, and a second signal electrode provided near the rotating body to be positioned such that a rotation of the rotating body causes the second signal electrode to be electrically connected to another end of the movable electrode. Further, a drive section causes, based on a first control signal, the rotating body to rotate until the movable electrode and the second signal electrode are electrically connected, and causes, based on a second control signal, the rotating body to rotate until the movable electrode and the second signal electrode are disconnected.

Abstract: An acoustic thin film resonator including: a first piezoelectric thin film 101; a pair of primary electrodes 103 and 104 for applying an electric signal, which are formed on the first piezoelectric thin film; a second piezoelectric thin film 102 that is disposed so that an oscillation generated in the first piezoelectric thin film propagates to the second piezoelectric thin film; a pair of secondary electrodes 104 and 105 for outputting an electric signal, which are formed on the second piezoelectric thin film; a load 108 that is connected between the secondary electrodes; and a control portion 109 that controls a value of the load. Thereby, an acoustic thin film resonator element is formed so that an electric signal inputted from the primary electrodes is outputted from the secondary electrodes by a piezoelectric effect, and a resonant frequency and an antiresonant frequency are made variable through the control of the value of the load.