A surface acoustic wave filter includes first and second signal terminals and first and second IDT electrodes that are adjacent to or in a vicinity of each other in an x-axis direction and that each includes a pair of comb-shaped electrodes each including a busbar electrode extending in the x-axis direction and electrode fingers extending in a y-axis direction. One of the comb-shaped electrodes in each of the first and second IDT electrodes is electrically connected to the first and second signal terminals, respectively. The surface acoustic wave filter further includes a bridging capacitance including a pair of comb-shaped electrodes arranged in a region outside an overlap region of the electrode fingers. One of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the first IDT electrode. The other of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the second IDT electrode.

In an arrangement having a DMS filter, it is provided to symmetrically divide at least one of the transducers (W) of the DMS filter (DMS) into two sub-transducers (T,T′) electrically connected in parallel and to shift them apart from each other by an amount of at least a half wavelength. This results in the signals of the two sub-transducers canceling each other out at a frequency in a stopband and thereby generating an attenuation pole in the upper blocking region.

An elastic wave filter has an unbalanced signal terminal, first and second balanced signal terminals, and first through fifth IDT electrodes arranged in ordinal order between a pair of grating reflectors. Wiring electrodes of the third and fifth IDT electrodes are disposed adjacent a ground electrode of the fourth IDT electrode, wiring electrodes of the second and third IDT electrodes are disposed adjacent one another, and ground electrodes of the first and second IDT electrodes are disposed adjacent one another. The unbalanced signal terminal is connected to the wiring electrodes of the first, third, and fifth IDT electrodes, and the first and second balanced signal terminals are connected to the wiring electrodes of the second and fourth IDT electrodes, respectively. A pitch gradation of pitch spacing between electrode fingers in each of the first, second, and third IDT electrodes on one side of a center line in the third IDT electrode is gradually reduced by a first spacing α, and a pitch gradation of pitch spacing between electrode fingers in each of the third, fourth, and fifth IDT electrodes on the other side of the center line is gradually reduced by a second spacing β (β≠α), as the distance from the center line increases.

An electronic component has a support member, an SAW element which is mounted on the support member with a space S therebetween and which has a facing surface which faces the support member, and a resin portion which covers the SAW element and which is provided so as to seal the space S. The SAW element has a piezoelectric substrate, an IDT provided on the facing surface of the piezoelectric board, an wiring (an outer wiring) which is provided on the facing surface of the piezoelectric board and extends from the IDT toward the periphery side of the piezoelectric board, and a dam member which is adjacent to a lateral edge portion of the wiring and which is provided locally relative to the circumferential direction which surrounds the IDT.

A surface acoustic wave filter device includes surface acoustic wave filters, one of which includes a longitudinally coupled resonator-type first filter section and a longitudinally coupled resonator-type second filter section. The second filter section is electrically connected in parallel or series with the first filter section on at least one of an input signal side and an output signal side. The first filter section includes a first IDT group including three IDTs. The second filter section includes a second IDT group including three IDTs. Another surface acoustic wave filter includes a third IDT group that is cascade connected to the first filter section and the second filter section and includes IDTs arranged in order in a line in a surface acoustic wave propagation direction.

In an arrangement having a DMS filter, it is provided to symmetrically divide at least one of the transducers (W) of the DMS filter (DMS) into two sub-transducers (T,T) electrically connected in parallel and to shift them apart from each other by an amount of at least a half wavelength. This results in the signals of the two sub-transducers canceling each other out at a frequency in a stopband and thereby generating an attenuation pole in the upper blocking region.

A surface acoustic wave filter includes first and second signal terminals and first and second IDT electrodes that are adjacent to or in a vicinity of each other in an x-axis direction and that each includes a pair of comb-shaped electrodes each including a busbar electrode extending in the x-axis direction and electrode fingers extending in a y-axis direction. One of the comb-shaped electrodes in each of the first and second IDT electrodes is electrically connected to the first and second signal terminals, respectively. The surface acoustic wave filter further includes a bridging capacitance including a pair of comb-shaped electrodes arranged in a region outside an overlap region of the electrode fingers. One of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the first IDT electrode. The other of the comb-shaped electrodes of the bridging capacitance is electrically connected to the comb-shaped electrode in the second IDT electrode.

The present invention relates to a surface acoustic wave filter device with floating units. The surface acoustic wave filter device comprises a piezoelectric substrate, at least one interdigitated transducer configuration and at least one floating unit. The interdigitated transducer configuration comprises a plurality of interdigitated transducer units disposed on the piezoelectric substrate. The floating unit is disposed between adjacent interdigitated transducer units, and covers partial region of adjacent interdigitated transducer units to reduce the BAW scattering of the surface acoustic wave filter device, and can be used to improve the amplitude and phase balances of the surface acoustic wave filter devices.

A SAW device (1) comprises a substrate (3); SAW elements (10) on a first main surface (3a) of the substrate (3); first lines (intermediate lines (29) and output side lines (31)) that are disposed upon the first main face (3a) and connected to the SAW elements (10); an insulator (21) that is layered upon the first lines; second lines (a second ground line (33b) and a third ground line (33c)) that are layered upon the insulator (21) and configure three-dimensional wiring parts (39) with the first lines; and a cover (5) that seals the SAW elements (10) and the three-dimensional wiring parts (39). Wiring spaces (53), formed between the first main face (3a) and the cover (5), houses the three-dimensional wiring parts (39), without housing the SAW elements (10).

An elastic wave element has a piezoelectric substrate; an excitation electrode which is located on an upper surface of the piezoelectric substrate and generates an acoustic wave, and two reflectors which are located on the upper surface of the piezoelectric substrate and sandwich the excitation electrode in the propagation direction of the acoustic wave. The excitation electrode has a main region located between the two end parts of the propagation direction and outer regions located on two sides of the main region. When the number of the electrode fingers of the outer region is m, an electrode finger interval of the main region is a, and an interval between the electrode finger of the main region on the outer region side and the reflector electrode finger of the reflector is x, 0.5a(m+1)<x<a(m+1) is satisfied. Further, a resonant frequency of the reflector is lower than a resonant frequency in the main region of the excitation electrode.