A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate; lower and upper electrodes facing each other across at least a part of the piezoelectric film; a first insertion layer located between the lower and upper electrodes and located in at least a part of an outer peripheral region within a resonance region in which the lower and upper electrodes face each other across the piezoelectric film, the first insertion layer being not located in a center region of the resonance region; and a second insertion layer located between the lower and upper electrodes and located in at least a part of the outer peripheral region, the second insertion layer being not located in the center region, a position of an edge of the second insertion layer being different from a position of an edge of the first insertion film in the resonance region.

A piezoelectric thin film resonator includes: a substrate; a piezoelectric film located on the substrate; lower and upper electrodes facing each other across at least a part of the piezoelectric film; a first insertion layer located between the lower and upper electrodes and located in at least a part of an outer peripheral region within a resonance region in which the lower and upper electrodes face each other across the piezoelectric film, the first insertion layer being not located in a center region of the resonance region; and a second insertion layer located between the lower and upper electrodes and located in at least a part of the outer peripheral region, the second insertion layer being not located in the center region, a position of an edge of the second insertion layer being different from a position of an edge of the first insertion film in the resonance region.

An RF circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.

An RF circuit device using modified lattice, lattice, and ladder circuit topologies. The devices can include four resonator devices and four shunt resonator devices. In the ladder topology, the resonator devices are connected in series from an input port to an output port while shunt resonator devices are coupled the nodes between the resonator devices. In the lattice topology, a top and a bottom serial configurations each includes a pair of resonator devices that are coupled to differential input and output ports. A pair of shunt resonators is cross-coupled between each pair of a top serial configuration resonator and a bottom serial configuration resonator. The modified lattice topology adds baluns or inductor devices between top and bottom nodes of the top and bottom serial configurations of the lattice configuration. These topologies may be applied using single crystal or polycrystalline bulk acoustic wave (BAW) resonators.

A temperature compensated oscillation circuit includes an oscillation circuit that oscillates a resonator, a fractional N-PLL circuit that multiplies frequency of an oscillation signal which is output by the oscillation circuit, on the basis of a frequency division ratio which is input, a temperature measurement unit that measures temperature, and a storage unit that stores a temperature correction table for correcting frequency temperature characteristics of the oscillation signal, in which the frequency division ratio of the fractional N-PLL circuit is set on the basis of a measurement value obtained by the temperature measurement unit and the temperature correction table.

A temperature compensated oscillation circuit includes an oscillation circuit that oscillates a resonator, a fractional N-PLL circuit that multiplies frequency of an oscillation signal which is output by the oscillation circuit, on the basis of a frequency division ratio which is input, a temperature measurement unit that measures temperature, and a storage unit that stores a temperature correction table for correcting frequency temperature characteristics of the oscillation signal, in which the frequency division ratio of the fractional N-PLL circuit is set on the basis of a measurement value obtained by the temperature measurement unit and the temperature correction table.

A resonator device comprising a piezoelectric material and at least one electrode, the device also provided with a material with a positive coefficient of stiffness, wherein the material is disposed in the device as an electrode or as a separate layer adjacent the piezoelectric material formed as one or more layers in the device. The material that performs the temperature compensating function is selected from the group consisting of ferromagnetic metal alloys, shape-memory metal alloys, and polymers, wherein the selected material has a temperature coefficient that varies with the relative amounts of the individual constituents of the compositions and wherein the composition is selected to provide the material with the positive coefficient of stiffness.

A resonator device comprising a piezoelectric material and at least one electrode, the device also provided with a material with a positive coefficient of stiffness, wherein the material is disposed in the device as an electrode or as a separate layer adjacent the piezoelectric material formed as one or more layers in the device. The material that performs the temperature compensating function is selected from the group consisting of ferromagnetic metal alloys, shape-memory metal alloys, and polymers, wherein the selected material has a temperature coefficient that varies with the relative amounts of the individual constituents of the compositions and wherein the composition is selected to provide the material with the positive coefficient of stiffness.

The invention relates to a microelectromechanical resonator device comprising a support structure and a semiconductor resonator plate doped to a doping concentration with an n-type doping agent and being capable of resonating in a width-extensional resonance mode. In addition, there is at least one anchor suspending the resonator plate to the support structure and an actuator for exciting the width-extensional resonance mode into the resonator plate. According to the invention, the resonator plate is doped to a doping concentration of 1.2*10.sup.20 cm.sup.−3 or more and has a shape which, in combination with said doping concentration and in said width-extensional resonance mode, provides the second order temperature coefficient of frequency (TCF.sub.2) to be 12 ppb/C.sup.2 or less at least at one temperature. Several practical implementations are presented.

A bulk acoustic resonator filter includes a plurality of bulk acoustic resonators connected between first and second radio frequency (RF) ports to form a frequency band, wherein each of the plurality of bulk acoustic resonators includes a first electrode, a second electrode, and a piezoelectric layer disposed between the first and second electrodes, the plurality of bulk acoustic resonators include first and second bulk acoustic resonators having different differences between a resonant frequency and an antiresonant frequency, and different ratios of a thickness of the piezoelectric layer to a total thickness of the first and second electrodes, and/or different thicknesses of the piezoelectric layer.