An electronic device according to an embodiment includes: an antenna, a filter configured to pass a signal of a specific frequency band among signals transmitted and received through the antenna, and a processor configured to control the filter to pass the signal of the specific frequency band. The filter includes: a first substrate, a second substrate facing the first substrate, a first group of electrodes disposed inside the first substrate, a second group of electrodes disposed inside the second substrate, a first transducer electrode including a first group of lines, a second transducer electrode including a second group of lines disposed to alternate with the first group of lines, and a power supply configured to apply voltages to the first group of electrodes and the second group of electrodes. The processor is configured to cause at least one of the second group of lines to be separated from the first substrate, by controlling the power supply based on a frequency of a signal to be passed through the filter.

A method for manufacturing a vibrator that includes forming excitation electrodes, lead-out electrodes, and first sealing frames on the main surfaces of a crystal piece; forming second sealing frames on the main surfaces of a base part and a lid part; and sealing a crystal vibration element by bonding the first sealing frames to the second sealing frames. The first sealing frames each include a first Ti or Cr base layer 110, and a first Au surface layer. The first Ti or Cr base layers are thinner than the first Au surface layers. The second sealing frames each include a second Ni base layer, and a second AuSn surface layer. The second Ni base layers are thicker than the second AuSn surface layers. The sealing is carried out by alloying the first Au surface layers and the second AuSn surface layers to each other.

Provided is a multiplexer that includes a first filter (first transmission filter), a second filter (second reception filter), a third filter (third reception filter), a first inductor, and a second inductor. The first inductor is connected in series with one parallel arm resonator (second parallel arm resonator) of the first filter between the one parallel arm resonator and ground. The second inductor is connected in series with another parallel arm resonator (third parallel arm resonator) of the first filter between the other parallel arm resonator and ground. The first inductor and the second inductor have the same winding direction as each other from the first filter side toward the ground side thereof.

A resonator device includes a resonator element, a base which has a first surface and a second surface that are in front-back relation, and in which the resonator element is arranged at the first surface, an integrated circuit provided to the base, a lid which has an inner surface opposed to the resonator element, and an outer surface in a front-back relationship with the inner surface, and which is bonded to the base so as to house the resonator element, and a radiation layer which is arranged at the inner surface of the lid, and is higher in emissivity than the lid.

A filter device having a reduced sensitivity to production tolerances comprises a multilayer panel with integrated wiring, a piezoelectric substrate mounted to the panel. A first filter circuit (FC.sub.1) and a signal path (SP) comprising a second filter circuit are realized on the substrate and connected to a common antenna terminal (AT) as well as to a common node (CN) located on top of the piezoelectric substrate. A first matching circuit (MC.sub.1) and further matching circuits (MC.sub.2) are realized by the wiring in the multilayer panel.

A resonator is provided that includes a vibrating section that vibrates in a contour vibration mode, a frame that surrounds at least a portion of the vibrating section, supporting sections extending along a Y-axis direction and connecting the vibrating section and the frame. The vibrating section includes a through hole that extends along an X-axis direction perpendicular to the Y-axis direction such that a coupling section is disposed between the through hole and each of the supporting sections. The length SL of the through hole in the X-axis direction is longer than the length Sd of the coupling section in the Y-axis direction.

A resonator device includes: a resonator element; a first package accommodating the resonator element; a heater bonded to the first package; and a second package accommodating the first package and the heater. The first package includes: a base substrate that has a first surface on which the resonator element is disposed and a second surface in a front-back relation with the first surface, and that contains single crystal silicon; an integrated circuit that is provided on the first surface or the second surface and that includes a temperature sensor; and a lid that is bonded to the base substrate such that the resonator element is accommodated between the lid and the base substrate.

A structure and method for integrating a crystal resonator with a control circuit are disclosed. The integration of the crystal resonator with the control circuit is accomplished by bonding a substrate (300) containing an upper cavity (310) to a device wafer containing both the control circuit and a lower cavity (120) so that a piezoelectric vibrator is sandwiched between the device wafer (100) and the substrate (300). In addition, a semiconductor die (700) may be bonded to a back side of the device wafer (100).

A resonator is provided that includes a vibration part, a frame, and a support arm. The vibration part includes an Si substrate that has a principal surface with a width W in an X-axis direction and a length L in a Y-axis direction. The vibration part is configured to vibrate mainly in a contour vibration mode. The support arm extends in the Y-axis direction and connects the frame to one of two ends in the Y-axis direction of the vibration part. When the principal surface of the Si substrate is viewed in a plan view, the width W is at its maximum Wmax at a point in the Y-axis direction and decreases with increasing proximity to the one of the two end portions in the Y-axis direction of the vibration part and with increasing proximity to the other end portion in the Y-axis direction of the vibration part.

A resonator element includes a quartz crystal substrate including a supporting section, a resonating section, and a coupling section coupling the supporting section and the resonating section and having thickness smaller than the thickness of the supporting section, the supporting section including a first principal plane and a first side surface coupling the first principal plane and the coupling section, a first excitation electrode disposed in the resonating section, a second excitation electrode disposed in the resonating section and overlapping the first excitation electrode via the resonating section, and first and second pad electrodes including portions disposed on the first principal plane, the first and second pad electrodes being electrically coupled to the first and second excitation electrodes.