In an example, a system includes a BAW resonator. The system also includes a first heater configured to heat the BAW resonator, where the first heater is controlled by a first control loop. The system includes a circuit coupled to the BAW resonator. The system also includes a second heater configured to heat the circuit, where the second heater is controlled by a second control loop.

In an example, a system includes a BAW resonator. The system also includes a first heater configured to heat the BAW resonator, where the first heater is controlled by a first control loop. The system includes a circuit coupled to the BAW resonator. The system also includes a second heater configured to heat the circuit, where the second heater is controlled by a second control loop.

A resonator device includes: a resonator element; a heat generating unit; a first package including a first base at which the resonator element and the heat generating unit are disposed, and a first lid bonded to the first base so as to accommodate the resonator element between the first lid and the first base; and a high emissivity layer that is disposed at a surface of the heat generating unit on a first lid side and that has an emissivity higher than an emissivity of the surface. In addition, a constituent material of the surface is silicon, and the emissivity of the high emissivity layer at room temperature is 0.5 or more.

A resonator device includes: a resonator element; a heat generating unit; a first package including a first base at which the resonator element and the heat generating unit are disposed, and a first lid bonded to the first base so as to accommodate the resonator element between the first lid and the first base; and a low emissivity layer that is disposed at an inner surface of the first lid and that has an emissivity lower than an emissivity of the first lid. In addition, a constituent material of the first lid is silicon, and the emissivity of the low emissivity layer at room temperature is less than 0.5.

A resonator device includes: a resonator element; a heat generating unit; a first package including a first base at which the resonator element and the heat generating unit are disposed, and a first lid bonded to the first base so as to accommodate the resonator element between the first lid and the first base; and a low emissivity layer that is disposed at an inner surface of the first lid and that has an emissivity lower than an emissivity of the first lid. In addition, a constituent material of the first lid is silicon, and the emissivity of the low emissivity layer at room temperature is less than 0.5.

A resonator device includes a substrate, a heater provided to the substrate, a temperature sensor provided to the substrate, a resonator element having a bond part bonded to the substrate, and a lid bonded to the substrate so as to house the resonator element in cooperation with the substrate, and the bond part is arranged to overlap the heater in a plan view.

A resonator device includes a substrate, a heater provided to the substrate, a temperature sensor provided to the substrate, a resonator element having a bond part bonded to the substrate, and a lid bonded to the substrate so as to house the resonator element in cooperation with the substrate, and the bond part is arranged to overlap the heater in a plan view.

A high frequency module includes a mounting substrate, an acoustic wave filter, a protection member, a resin layer, and a shield layer. The acoustic wave filter is mounted on a first main surface of the mounting substrate. The protection member is disposed on a main surface of the acoustic wave filter that is far from the mounting substrate. The resin layer is disposed on the first main surface of the mounting substrate and covers an outer peripheral surface of the acoustic wave filter and an outer peripheral surface of the protection member. The shield layer covers the resin layer and the protection member. The protection member is in contact with both the acoustic wave filter and the shield layer. The acoustic wave filter includes a piezoelectric substrate. A main surface of the piezoelectric substrate that is far from the mounting substrate is in contact with the protection member.

A high frequency module includes a mounting substrate, an acoustic wave filter, a protection member, a resin layer, and a shield layer. The acoustic wave filter is mounted on a first main surface of the mounting substrate. The protection member is disposed on a main surface of the acoustic wave filter that is far from the mounting substrate. The resin layer is disposed on the first main surface of the mounting substrate and covers an outer peripheral surface of the acoustic wave filter and an outer peripheral surface of the protection member. The shield layer covers the resin layer and the protection member. The protection member is in contact with both the acoustic wave filter and the shield layer. The acoustic wave filter includes a piezoelectric substrate. A main surface of the piezoelectric substrate that is far from the mounting substrate is in contact with the protection member.

A packaged acoustic wave component has two acoustic wave devices interconnected by a thermally conductive frame, at least one of the acoustic wave devices including a multi-layer piezoelectric substrate. The multi-layer piezoelectric substrate includes a support layer and a piezoelectric layer disposed over the support layer. An interdigital transducer (IDT) electrode is disposed over the piezoelectric layer. The support layer has a high thermal conductivity, allowing heat generated by a first acoustic wave device with the multi-layer piezoelectric substrate to be transferred to a second acoustic wave device on which it is stacked to dissipate heat from the first acoustic wave device by way of the thermally conductive frame spaced from ends of the piezoelectric layers.