Patent application number | Description | Published |
20080266027 | LONGITUDINALLY-COUPLED-RESONATOR-TYPE ELASTIC WAVE FILTER DEVICE - In a longitudinally-coupled-resonator-type elastic wave filter device, at least one of two IDTs which are adjacent to each other is provided with a dummy electrode for series weighting in a portion in which the IDTs are adjacent to each other, and at least one of series-weighted portions includes at least one of metallization ratio reducing portion in a first acoustic track and metallization ratio increasing portion in a second acoustic track so as to reduce the difference between the metallization ratio of the first acoustic track passing through a connecting portion of the dummy electrode and the metallization ratio of each of second and third acoustic tracks each placed on either side of the first acoustic track in the direction of propagation of an elastic wave. | 10-30-2008 |
20090021322 | ELASTIC WAVE FILTER DEVICE AND DUPLEXER - An elastic wave filter device includes first and second elastic wave filter units connected to an unbalanced terminal. The first and second elastic wave filter units include first to third IDTs and fourth to sixth IDTs, respectively. One end of the first IDT, one end of the second IDT, one end of the fourth IDT, and one end of the sixth IDT are commonly connected together and are connected to the unbalanced terminal. The second IDT and the fifth IDT are each divided into first to third sub-IDT portions in the elastic wave propagation direction, respectively. The second sub-IDT portions of the second and fifth IDTs are connected to first and second balanced terminals, respectively. | 01-22-2009 |
20090115547 | BOUNDARY ACOUSTIC WAVE FILTER - A longitudinally coupled resonator boundary acoustic wave filter device includes a piezoelectric substrate made of LiNbO | 05-07-2009 |
20090121810 | ACOUSTIC WAVE FILTER - A longitudinally coupled resonator acoustic wave filter device that utilizes an inter-IDT resonance mode with a reduced insertion loss has a structure in which apodization weights are assigned in first to third IDTs having narrow pitch electrode finger portions in portions other than the narrow pitch electrode finger portions, such that the electrode finger overlap width sequentially varies in an acoustic wave propagating direction in which an acoustic wave propagates, and portions of the IDTs located at ends adjacent to the narrow pitch electrode finger portions have a maximum electrode finger overlap width. | 05-14-2009 |
20090160574 | BOUNDARY ACOUSTIC WAVE FILTER - A boundary acoustic wave filter device includes an electrode structure provided at a boundary between a piezoelectric body and a dielectric body laminated on the piezoelectric body and utilizes an SH-type boundary acoustic wave that propagates along the boundary. In the boundary acoustic wave filter device, the electrode structure includes a longitudinally coupled resonator boundary acoustic wave filter portion that has a first IDT and second and third IDTs arranged respectively on both sides of the IDT in a direction in which the boundary acoustic wave propagates. At portions at which two IDTs are located adjacent to each other in the direction in which the boundary acoustic wave propagates, narrow pitch electrode finger portions are provided in the IDTs, and the pitch of the electrode fingers of the narrow pitch electrode finger portion is different from the pitch of the electrode fingers of each of the narrow pitch electrode finger portions. | 06-25-2009 |
20090174284 | BOUNDARY ACOUSTIC WAVE DEVICE - A boundary acoustic wave device includes a piezoelectric substance made of LiNbO | 07-09-2009 |
20100207707 | ACOUSTIC WAVE FILTER DEVICE - An acoustic wave filter device is capable of increasing the steepness of a filter characteristic at a boundary between a passband and an attenuation band and achieving a low loss in the passband. The acoustic wave filter device has a ladder circuit configuration including a plurality of series arm resonators and at least one parallel arm resonator. The anti-resonant frequency of the series arm resonator is different from that of the series arm resonator. The series arm resonator having the lowest anti-resonant frequency has a resonant frequency located in the passband and an electromechanical coupling coefficient less than an average of electromechanical coupling coefficients of the series arm resonators. | 08-19-2010 |
20100301969 | ACOUSTIC WAVE DEVICE - A longitudinally-coupled resonator-type acoustic wave device includes first to third IDT electrodes disposed on a piezoelectric material and first and second reflectors disposed in acoustic wave propagation directions. Each of any two IDT electrodes adjacent to each other in the acoustic wave propagation directions, of the first to third IDT electrodes, has a narrower-pitch electrode finger portion at an edge thereof adjacent to the other IDT electrode. Most portions of the first to third IDT electrodes are apodized, and the narrower-pitch electrode finger portions and the electrode finger portions adjacent thereto are normally shaped. | 12-02-2010 |