Abstract: An acoustic wave filter device having a balanced-to-unbalanced conversion function, in which the signal balance between a pair of balanced terminals is improved, has, on a piezoelectric substrate, one end of at least of one longitudinally coupled resonator type acoustic wave filter and one end of at least one acoustic wave filter among the rest of acoustic wave filters are commonly connected and connected to an unbalanced terminal, and the other ends of the longitudinally coupled resonator type acoustic wave filters are electrically connected to first and second balanced terminals, respectively, in which a signal input from the unbalanced terminal is configured such that the phase difference of a signal output from the first balanced terminal and a signal output from the second balanced terminal is approximately 180 degrees, and in which a propagation direction of an acoustic wave in the longitudinally coupled resonator type acoustic wave filter and a propagation direction of an acoustic wave in the second lo

Abstract: A surface acoustic wave filter device includes an unbalanced terminal, first and second balanced terminals, and first, second and third IDTs. One end of the first IDT and one end of the third IDT are connected to the unbalanced terminal. The second IDT includes first and second divided IDT portions obtained by dividing the IDT in the surface wave propagating direction. The first and second divided IDT portions include sub-divided IDT portions and sub-divided IDT portions obtained by dividing the first and second divided IDT portions and in the crossing width direction. The first and second divided IDT portions are electrically connected in series. The first and second sub-divided IDT portions are electrically connected in series. The first and second sub-divided IDT portions are electrically connected in series. The second sub-divided IDT portion is connected to the first balanced terminal and the second sub-divided IDT portion is connected to the second balanced terminal.

Abstract: An elastic wave filter includes two longitudinally coupled resonator type elastic wave filter elements that are cascade connected with each other, each longitudinally coupled resonator type elastic wave filter element including three IDTs (interdigital transducers) arranged on a piezoelectric substrate in a transmitting direction of an elastic wave. In at least one of the longitudinally coupled resonator type elastic wave filter elements, electrode fingers of the IDTs that are cascade connected are arranged at a pitch that is smaller than a pitch of electrode fingers of the remaining IDT. The adverse effect of a parasitic capacitance in cascade connected wires disposed between the longitudinally coupled resonator type elastic wave filter elements is reduced so as to improve impedance matching of a cascade connected portion and to improve the VSWR characteristics of input-output terminals of the elastic wave filter.

Abstract: A probe array base including probe-holding portions which are periodically arranged on a solid base member and which have grooves is prepared by anisotropically etching a single-crystalline silicon substrate. Probe solutions are supplied to the probe-holding portions by capillary action from a plurality of tank arrays having a certain cylinder period. This allows a probe array to be completed. The probe array is used as, for example, a DNA or antigen chip, has a high degree of integration, and is capable of holding a constant and sufficient number of probe molecules.

Abstract: A surface acoustic wave filter device includes an unbalanced terminal, first and second balanced terminals, and first, second and third IDTs. One end of the first IDT and one end of the third IDT are connected to the unbalanced terminal. The second IDT includes first and second divided IDT portions obtained by dividing the IDT in the surface wave propagating direction. The first and second divided IDT portions include sub-divided IDT portions and sub-divided IDT portions obtained by dividing the first and second divided IDT portions and in the crossing width direction. The first and second divided IDT portions are electrically connected in series. The first and second sub-divided IDT portions are electrically connected in series. The first and second sub-divided IDT portions are electrically connected in series. The second sub-divided IDT portion is connected to the first balanced terminal and the second sub-divided IDT portion is connected to the second balanced terminal.

Abstract: An acoustic wave filter device includes a piezoelectric substrate and a longitudinally coupled resonator surface acoustic wave filter unit provided on the piezoelectric substrate. The surface acoustic wave filter unit includes first to fifth IDTs arranged in a surface wave propagation direction. The first, third, and fifth IDTs are connected to an unbalanced terminal, while the second and fourth IDTs are connected to first and second balanced terminals, respectively. The second IDT includes first and second sub-IDT portions obtained by dividing the second IDT and arranged in a crossing width direction, and the fourth IDT includes first and second sub-IDT portions obtained by dividing the fourth IDT and arranged in the crossing width direction. The first and second sub-IDT portions are connected in series. The first and second sub-IDT portions are also connected in series.

Abstract: A boundary acoustic wave filter device capable of increasing an out-of-band attenuation includes a dielectric film formed on a piezoelectric substrate, at least one longitudinally coupled resonator boundary acoustic wave filter having a plurality of IDTs disposed along a boundary between the piezoelectric substrate and the dielectric film, and at least two one-terminal-pair boundary acoustic wave resonators. At least one boundary acoustic wave resonator is connected in series to the longitudinally coupled resonator boundary acoustic wave filter, and at least remaining one boundary acoustic wave resonator is connected in parallel to the longitudinally coupled resonator boundary acoustic wave filter.

Abstract: A surface acoustic wave (SAW) filter includes a piezoelectric substrate. A resin pattern having a permittivity less than that of the piezoelectric substrate and first and second conductor patterns are disposed on the piezoelectric substrate. The first conductor pattern defines two one-terminal-pair SAW resonators and two longitudinally coupled resonator SAW filters. A portion of the second conductor pattern defines wiring traces having different potentials. Portions of the wiring traces facing each other in a plan view are disposed on the resin pattern.

Abstract: An acoustic wave filter device includes a piezoelectric substrate and a longitudinally coupled resonator surface acoustic wave filter unit provided on the piezoelectric substrate. The surface acoustic wave filter unit includes first to fifth IDTs arranged in a surface wave propagation direction. The first, third, and fifth IDTs are connected to an unbalanced terminal, while the second and fourth IDTs are connected to first and second balanced terminals, respectively. The second IDT includes first and second sub-IDT portions obtained by dividing the second IDT and arranged in a crossing width direction, and the fourth IDT includes first and second sub-IDT portions obtained by dividing the fourth IDT and arranged in the crossing width direction. The first and second sub-IDT portions are connected in series. The first and second sub-IDT portions are also connected in series.

Abstract: In an acoustic wave filter device, first and second surface acoustic wave filter sections implemented by longitudinally coupled resonators are arranged on a piezoelectric substrate. The first and second surface acoustic wave filter sections include first to third interdigital transducers and fourth to sixth interdigital transducers, respectively, arranged in a direction of propagation of surface waves. The first, third, fourth, and sixth interdigital transducers are connected to an unbalanced terminal. The second and fifth interdigital transducers are connected to first and second balanced terminals, respectively. Each of the second and fifth interdigital transducers has first and second interdigital transducer segments divided in the direction of propagation of acoustic waves. The first and second interdigital transducer segments are connected in series with each other.

Abstract: A longitudinally-coupled-resonator-type surface acoustic wave filter includes three interdigital transducers provided on a piezoelectric substrate in the direction in which surface acoustic waves propagate. An interdigital transducer disposed at the approximate center among the three interdigital transducers of the longitudinally-coupled-resonator-type surface acoustic wave filter is divided into two parts substantially symmetrically in the propagation direction of the surface acoustic waves and the two parts are connected to balanced signal terminals, respectively. Left and right interdigital transducers of which the polarities are inverted relative to each other are connected to an unbalanced signal terminal to provide a balanced-to-unbalanced conversion function. A reactance component provided on the piezoelectric substrate, inside a package, or outside the package is connected to either of the balanced signal terminals.

Abstract: In a surface acoustic wave device in which balanced terminals extend from series IDTs, noise coming from an electrical-potential signal at the series connection point of the series IDTs is removed to improve the degree of balance. A surface acoustic wave filter includes a pair of surface acoustic wave reflectors disposed on a piezoelectric substrate along the propagation direction of surface acoustic waves, and a plurality of IDTs disposed between the two surface acoustic wave reflectors. Two opposing electrode fingers of the IDTs, which are series IDTs, are connected to corresponding balanced terminals, and the series connection point thereof is grounded. As a result, noise coming from an abnormal electrical-potential signal generated at the series connection point is removed to improve the degree of balance between the balanced terminals.

Abstract: A bandpass filter unit includes first and second bandpass filters having substantially the same pass-band characteristics. The first and second bandpass filters are connected in parallel with each other. At least one phase shifter for shifting the phase is connected to at least one of the first and second filters. Accordingly, reflected waves occurring in the first and second bandpass filters cancel out each other at an input terminal pair and an output terminal pair.

Abstract: A surface acoustic wave filter includes a first reflector, a first IDT, a second IDT, a third IDT, and a second reflector arranged in that order on a piezoelectric substrate. The first IDT and the third IDT, connected in parallel, are together also connected to an unbalanced signal terminal. The second IDT includes two separate comb-like electrodes arranged in the direction of propagation of a surface acoustic wave, and electrically connected in series to each other at a serial junction. The comb-like electrodes are respectively connected to balanced signal terminals. The outermost electrode finger of the first IDT is connected to the unbalanced signal terminal, and the outermost electrode finger of the third IDT is grounded.

Abstract: In a surface acoustic wave device in which balanced terminals extend from series IDTs, noise coming from an electrical-potential signal at the series connection point of the series IDTs is removed to improve the degree of balance. A surface acoustic wave filter includes a pair of surface acoustic wave reflectors disposed on a piezoelectric substrate along the propagation direction of surface acoustic waves, and a plurality of IDTs disposed between the two surface acoustic wave reflectors. Two opposing electrode fingers of the IDTs, which are series IDTs, are connected to corresponding balanced terminals, and the series connection point thereof is grounded. As a result, noise coming from an abnormal electrical-potential signal generated at the series connection point is removed to improve the degree of balance between the balanced terminals.

Abstract: A surface acoustic wave (SAW) filter includes a piezoelectric substrate. A resin pattern having a permittivity less than that of the piezoelectric substrate and first and second conductor patterns are disposed on the piezoelectric substrate. The first conductor pattern defines two one-terminal-pair SAW resonators and two longitudinally coupled resonator SAW filters. A portion of the second conductor pattern defines wiring traces having different potentials. Portions of the wiring traces facing each other in a plan view are disposed on the resin pattern.

Abstract: A vibrator includes: a vibrating body; a driving unit for causing the vibrating body to vibrate in a predetermined vibrating direction; and a driving monitoring unit for detecting vibration displacement in a driving direction of the vibrating body. Stabilization of vibration in the driving direction of the vibrating body is achieved by applying positive feedback control to the driving unit based on the state of the vibration displacement in the driving direction of the vibrating body detected by this driving monitoring unit. The driving monitoring unit is constructed and arranged so as to be provided in a barycentric region of the vibrating body to detect the vibration displacement in the driving direction of the barycentric region of the vibrating body.

Abstract: A longitudinally-coupled-resonator-type surface acoustic wave filter includes three interdigital transducers provided on a piezoelectric substrate in the direction in which surface acoustic waves propagate. An interdigital transducer disposed at the approximate center among the three interdigital transducers of the longitudinally-coupled-resonator-type surface acoustic wave filter is divided into two parts substantially symmetrically in the propagation direction of the surface acoustic waves and the two parts are connected to balanced signal terminals, respectively. Left and right interdigital transducers of which the polarities are inverted relative to each other are connected to an unbalanced signal terminal to provide a balanced-to-unbalanced conversion function. A reactance component provided on the piezoelectric substrate, inside a package, or outside the package is connected to either of the balanced signal terminals.

Abstract: A surface acoustic wave filter includes a first reflector, a first IDT, a second IDT, a third IDT, and a second reflector arranged in that order on a piezoelectric substrate. The first IDT and the third IDT, connected in parallel, are together also connected to an unbalanced signal terminal. The second IDT includes two separate comb-like electrodes arranged in the direction of propagation of a surface acoustic wave, and electrically connected in series to each other at a serial junction. The comb-like electrodes are respectively connected to balanced signal terminals. The outermost electrode finger of the first IDT is connected to the unbalanced signal terminal, and the outermost electrode finger of the third IDT is grounded.

Abstract: A bandpass filter unit includes first and second bandpass filters having substantially the same pass-band characteristics. The first and second bandpass filters are connected in parallel with each other. At least one phase shifter for shifting the phase is connected to at least one of the first and second filters. Accordingly, reflected waves occurring in the first and second bandpass filters cancel out each other at an input terminal pair and an output terminal pair.