Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

A micro-electrical-mechanical system (MEMS) guided wave device includes a plurality of electrodes arranged below a piezoelectric layer (e.g., either embedded in a slow wave propagation layer or supported by a suspended portion of the piezoelectric layer) and configured for transduction of a lateral acoustic wave in the piezoelectric layer. The piezoelectric layer permits one or more additions or modifications to be made thereto, such as trimming (thinning) of selective areas, addition of loading materials, sandwiching of piezoelectric layer regions between electrodes to yield capacitive elements or non-linear elastic convolvers, addition of sensing materials, and addition of functional layers providing mixed domain signal processing utility.

A front-end module may include an acoustic wave filter with a first and second interdigital transducer electrode. The first interdigital transducer electrode may be single-ended with a first input bus bar that receives an input signal and a second input bus bar connected to ground. The second interdigital transducer electrode may be differential with a first output bus bar connected to a first output terminal and a second output bus bar connected to a second output terminal. The front-end module may include a low noise amplifier (LNA) that outputs a differential signal via a differential output and has a differential input connected to the acoustic wave filter. The LNA may include a first input transistor that receives a first signal from the first output terminal of the acoustic wave filter and a second input transistor that receives a second signal from the second output terminal of the acoustic wave filter.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

A filter device includes a port, a reference potential part, at least one filter, a signal line, a first inductor, and at least one second inductor. A signal is input through the port, and/or a signal is output through the port. The reference potential part is placed at a reference potential. The at least one filter filters a signal. The signal line connects the port to the at least one filter. The first inductor is at least part of the signal line. The second inductor forms a connection between the signal line and the reference potential part. The first inductor and the at least one second inductor are inductively coupled to each other.

A high-frequency module includes a module substrate including an internal wiring pattern, and a SAW filter including a piezoelectric substrate, an electrode pattern on the piezoelectric substrate, a support surrounding the electrode pattern, and a cover on the support covering the electrode pattern to define a hollow space together with the support and the piezoelectric substrate. The module substrate, the cover, and the piezoelectric substrate are disposed in this order in a perpendicular or substantially perpendicular direction with respect to the module substrate, and a shield electrode is provided on a surface of the cover that faces the module substrate or on a surface of the cover that faces the piezoelectric substrate.

A front-end module may include an acoustic wave filter with a first and second interdigital transducer electrode, and a low noise amplifier (LNA) that converts a differential input to a single-ended output with respect to ground. The first interdigital transducer electrode may be single-ended with a first input bus bar configured to receive an input signal and a second input bus bar connected to ground. The second interdigital transducer electrode may be differential with a first output bus bar connected to a first output terminal and a second output bus bar connected to a second output terminal. The LNA may have a differential input connected to the acoustic wave filter, a first input transistor that receives a first signal from the first output terminal of the acoustic wave filter, and a second input transistor that receives a second signal from the second output terminal of the acoustic wave filter.

In an acoustic wave device, an interdigital transducer electrode is disposed on a piezoelectric substrate with a reverse velocity surface having an elliptic shape, and a dielectric film is disposed to cover the interdigital transducer electrode. Assuming an electrode density (%) of the interdigital transducer electrode to be y (%) and a wavelength-normalized film thickness 100h/λ (%) of the interdigital transducer electrode to be x (%), the wavelength-normalized film thickness x of the interdigital transducer electrode takes a value not less than x satisfying y=0.3452x.sup.2−6.0964x+36.262 depending on the electrode density of the interdigital transducer electrode.

Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

A composite acoustic wave filter device includes first and second acoustic wave filters. One end of the first acoustic wave filter with a pass band in a relatively low frequency range and one end of the second acoustic wave filter with a pass band in a relatively high frequency range are connected in common. A first end portion of a first parallel capacitance element and a third end portion of a second parallel capacitance element are connected to a signal line of the second acoustic wave filter. A ground-side end portion of the first parallel capacitance element is connected in common to a ground-side end portion of the first acoustic wave filter. A fourth end portion of the second parallel capacitance element is connected to a ground potential.