Abstract: An acoustic wave filter has a first signal line connecting one among the plurality of first IDT electrodes and the first balanced signal terminal; a second signal line connecting the other first IDT electrode with the second balanced signal terminal; a third signal line connecting one among the plurality of second IDT electrodes with the second balanced signal terminal; and a fourth signal line connecting the other second IDT electrode with the first balanced signal terminal. The fourth signal line has an intersection portion three-dimensionally intersecting with a part of the second signal line. The intersection portion extends in a direction inclined relative to the second signal line on the major surface.

Abstract: The present invention provides a duplexer using a ladder-type filter, which has a small size and is superior in isolation characteristic, and a communication apparatus using such a duplexer. A series resonator (R1) contained in a first filter element (F1) and a parallel resonator (R4) contained in a second filter element (F2) are disposed so as not to allow the elastic wave propagating paths to be overlapped with each other. By disposing them in this manner, it is possible to prevent an elastic wave, leaked from the series resonator (R1) and most influential to the isolation characteristic, from being received by the parallel resonator (R4). Consequently, it is possible to achieve a small-size duplexer that is superior in isolation characteristic.

Abstract: The present invention provides a duplexer using a ladder-type filter, which has a small size and is superior in isolation characteristic, and a communication apparatus using such a duplexer. A series resonator (R1) contained in a first filter element (F1) and a parallel resonator (R4) contained in a second filter element (F2) are disposed so as not to allow the elastic wave propagating paths to be overlapped with each other. By disposing them in this manner, it is possible to prevent an elastic wave, leaked from the series resonator (R1) and most influential to the isolation characteristic, from being received by the parallel resonator (R4). Consequently, it is possible to achieve a small-size duplexer that is superior in isolation characteristic.

Abstract: A SAW device D1 according to the present invention comprises a ladder-type SAW device T1 for transmission and a ladder-type SAW device R2 for receiving on a main surface of a piezoelectric substrate. The ratio (LT/PT) of the width LT of electrode fingers to the pitch PT between the electrode fingers in a SAW resonator S1 in the ladder-type SAW device T1 for transmission is made lower than the ratio (LR/PR) of the width LR of electrode fingers to the pitch PR between the electrode fingers in a SAW resonator S2 in the ladder-type SAW device R2 for receiving. As a result, the SAW device D1 has a low loss within a band and has steep attenuation characteristics outside the band, and is miniaturized.

Abstract: After electrode patterning on an electrode forming surface of a piezoelectric substrate 2 (FIG. 1(b)), a conductor layer is formed on an electrode non-forming surface of the piezoelectric substrate 2 (FIG. 1(c)). After forming the conductor layer, the conductor layer formed on the other surface is removed (FIG. 1(f)) after at least one step (FIG. 1(e)), and thereafter, dicing for separation into elements and mounting on a mounting substrate are carried out. By removing all the conductor layer on the other surface of the piezoelectric substrate, the out-of-passband attenuation and isolation performance can be significantly improved.

Abstract: A gas analyzer apparatus including a support tube having a distal portion arranged in a flue and a gas sensor supported on the support tube. An air supply tube supplies cooling air into the support tube. A basal portion of the gas sensor is cooled by the cooling air.

Abstract: An ac generator for a vehicle includes a rotor having a field coil, a stator having a stator winding disposed around the rotor to provide ac power in cooperation with the rotor, a brush unit disposed near a rotation axis of the rotor, and a voltage regulator for controlling output voltage of the ac power. The voltage regulator has a regulator circuit section and a heat sink for dissipating heat generated by the regulator circuit section. The heat sink has a plurality of axially projecting cooling fins that extends in a circumferential direction of the rotor.

Abstract: An IDT electrode 3, and an input electrode section 5 and an output electrode section 6 each connecting with the IDT electrode 3 are formed in a filter region on one main surface of a piezoelectric substrate 2, and a semiconductor layer 22 is formed on the other main surface opposite to the one main surface of the piezoelectric substrate 2. The semiconductor layer 22 makes it possible to prevent pyroelectric destruction in the device manufacturing process as well as to prevent out-of-band attenuation characteristics from being degraded.

Abstract: A conductor layer 10 is provided so as to prevent pyroelectric destruction occurring in the steps of manufacturing a surface acoustic wave element 1 on the other surface opposite to an IDT electrode formation surface of a piezoelectric substrate 2. At this time, the conductor layer 10 is formed, except for a region 5a opposed to an input electrode section 5 in a filter region 9 and/or a region 6a opposed to an output electrode section 6. This allows a coupling amount between the input electrode section 5 and the output electrode section 6 due to a parasitic capacitance formed between the input electrode section 5 and the output electrode section 6 in the filter region 9 to be reduced, thereby allowing the out-of-band attenuation characteristics of a surface acoustic wave device to be improved.

Abstract: In a surface acoustic wave element 10, in which IDT electrodes 31 and 32, a grounding electrode 37, etc. are formed one main surface of a piezoelectric substrate 20, resistors 40 made of a semiconductor are provided to connection electrodes 38 that interconnect the respective electrodes. By forcing the charges generated in the IDT electrodes to move via the resistors 40, it is possible to provide a compact, highly reliable surface acoustic wave apparatus capable of preventing an electrostatic discharge damage in the IDT electrodes.

Abstract: The present invention provides an AC generator for a vehicle, capable of improving the cooling capability and environmental resistance of a rectifier. The rectifier of the vehicle AC generator includes a positive electrode side radiating fin and negative electrode side radiating fin disposed in piles in a axial direction, a positive electrode side rectifying elements and negative electrode side rectifying elements provided in the radiating fins, respectively, and a terminal board. The positive electrode side radiating fin is equipped with cylindrical fixing portions to which the positive electrode side rectifying elements are fixed and radial sub-fins extending radially from the fixing portions. An opening portion surrounded by the fixing portion, the radial sub-fin and others forms an axial air flow passage.

Abstract: A rotor and a stator are contained in a housing composed of front and rear frames, and a rectifier is mounted on the rear frame and covered with a rear cover having axial and radial openings. A minus heatsink plate having cooling fins extending in the axial direction is disposed to face the radial openings, forming radial air passages, and another air passage is formed between the minus heatsink plate and the rear frame. Cooling air introduced from the radial openings flows through the cooling fins and through the passage between the minus heatsink plate and the rear frame. Thus, efficiency for cooling the rectifier is enhanced.

Abstract: IDT electrodes are arranged on a piezoelectric substrate along a propagation direction of a surface acoustic wave whereas reflectors are each interposed between a respective pair of IDT electrodes, the reflectors each including four or more electrode fingers extended perpendicularly to the propagation direction. An electrode-finger pitch ‘a’ of the reflector is progressively decreased from the opposite ends of the reflector toward the center thereof. Frequencies allowed to pass through a pass band may be controlled by varying the electrode-finger pitch. Thus is provided a surface acoustic wave device featuring a wide-band transmission performance.

Abstract: A rotor and a stator are contained in a housing composed of front and rear frames, and a rectifier is mounted on the rear frame and covered with a rear cover having axial and radial openings. A minus heatsink plate having cooling fins extending in the axial direction is disposed to face the radial openings, forming radial air passages, and another air passage is formed between the minus heatsink plate and the rear frame. Cooling air introduced from the radial openings flows through the cooling fins and through the passage between the minus heatsink plate and the rear frame. Thus, efficiency for cooling the rectifier is enhanced.

Abstract: A SAW device D1 according to the present invention comprises a ladder-type SAW device T1 for transmission and a ladder-type SAW device R2 for receiving on a main surface of a piezoelectric substrate. The ratio (LT/PT) of the width LT of electrode fingers to the pitch PT between the electrode fingers in a SAW resonator S1 in the ladder-type SAW device T1 for transmission is made lower than the ratio (LR/PR) of the width LR of electrode fingers to the pitch PR between the electrode fingers in a SAW resonator S2 in the ladder-type SAW device R2 for receiving. As a result, the SAW device D1 has a low loss within a band and has steep attenuation characteristics outside the band, and is miniaturized.

Abstract: A rotor and a stator are contained in a housing composed of front and rear frames, and a rectifier is mounted on the rear frame and covered with a rear cover having axial and radial openings. A minus heatsink plate having cooling fins extending in the axial direction is disposed to face the radial openings, forming radial air passages, and another air passage is formed between the minus heatsink plate and the rear frame. Cooling air introduced from the radial openings flows through the cooling fins and through the passage between the minus heatsink plate and the rear frame. Thus, efficiency for cooling the rectifier is enhanced.

Abstract: A gas analyzer apparatus including a support tube having a distal portion arranged in a flue and a gas sensor supported on the support tube. An air supply tube supplies cooling air into the support tube. A basal portion of the gas sensor is cooled by the cooling air.

Abstract: An IDT electrode 3, and an input electrode section 5 and an output electrode section 6 each connecting with the IDT electrode 3 are formed in a filter region on one main surface of a piezoelectric substrate 2, and a semiconductor layer 22 is formed on the other main surface opposite to the one main surface of the piezoelectric substrate 2. The semiconductor layer 22 makes it possible to prevent pyroelectric destruction in the device manufacturing process as well as to prevent out-of-band attenuation characteristics from being degraded.

Abstract: A rotary electric machine includes a frame, a rectifying unit fixed to the frame, a rotor accommodated in the frame, a voltage regulator having a regulator section, an arm extending from the regulator section in a circumferential direction and a connector. The arm has a mounting potion at an end, and the connector is disposed between the mounting potion and the regulator portion.