RF communications circuitry, which includes a first tunable RF filter and an RF power amplifier (PA), is disclosed. The first tunable RF filter includes a pair of weakly coupled resonators, and receives and filters a first upstream RF signal to provide a first filtered RF signal. The RF PA is coupled to the first tunable RF filter, and receives and amplifies an RF input signal to provide an RF output signal.

A user equipment (UE) includes a transmit chain that includes multiple radio frequency transmitters, multiple power amplifiers and a front end (FE) through which signals are transmitted. To achieve a high power UE solution, aspects of the disclosure selectively combine two or more power amplifier outputs based on an expected power output of the UE. To synchronously combine the outputs, an output feedback signal from a feedback receiver is used to adjust a delay and a phase of one or more signals associated with the power amplifiers.

Embodiments of radio frequency (RF) front-end circuitry are disclosed where the RF front-end circuitry includes a tunable RF filter structure and a calibration circuit. The tunable RF filter structure includes (at least) a pair of weakly coupled resonators and defines a transfer function with a passband. The calibration circuit is configured to shape the passband so that the passband defines a center frequency. Additionally, the calibration circuit is configured to detect a phase difference at the target center frequency between the pair of weakly coupled resonators and adjust the phase difference of the pair of weakly coupled resonators at the target center frequency so as to reduce a frequency displacement between the center frequency of the passband and the target center frequency. In this manner, the calibration circuit calibrates the tunable RF filter structure to correct for errors in the center frequency of the passband due to component manufacturing variations.

RF front-end circuitry, which includes a first RF low noise amplifier (LNA) and a first reconfigurable RF filter, is disclosed. The RF front-end circuitry operates in one of a group of operating modes. The first reconfigurable RF filter, which has a first reconfigurable RF filter path, includes a first receive (RX) shunt switching element coupled between the first reconfigurable RF filter path and ground. The first reconfigurable RF filter path is coupled to an input of the first RF LNA. The group of operating modes includes a first operating mode and a second operating mode. During the first operating mode, the first RX shunt switching element is ON. During the second operating mode, the first RX shunt switching element is OFF and the first RF LNA receives and amplifies a first filtered RF receive signal from the first reconfigurable RF filter to provide a first receive signal.

In an acoustic wave device, a piezoelectric body is directly or indirectly laminated on a silicon support substrate, and a functional electrode is provided on the piezoelectric body. A support layer is directly or indirectly laminated on the silicon support substrate, and the support layer is located outside the functional electrode when viewed in plan view. A silicon cover layer is provided on the support layer that includes an insulating material, and a space A is defined by the silicon support substrate, the support layer, and the silicon cover layer. The electric resistance of the silicon support substrate is higher than the electric resistance of the silicon cover layer.

An acoustic wave device that includes a spinel layer, a piezoelectric layer, a temperature compensating layer between the spinel layer and the piezoelectric layer and an interdigital transducer electrode on the piezoelectric layer is disclosed. The piezoelectric layer is disposed between the interdigital transducer electrode and the spinel layer. The acoustic wave device is configured to generate an acoustic wave having a wavelength of λ. The piezoelectric layer can have a thickness that is less than λ. In some embodiments, the spinel layer can be a polycrystalline spinel layer.

This disclosure relates to variable-gain amplifiers that include degeneration circuits configured to adapt to a gain mode that is currently being implemented. For example, a variable-gain amplifier can operate in a plurality of gain modes to amplify a signal with different levels of amplification. The variable-gain amplifier can include a gain circuit configured to amplify a signal and a degeneration circuit coupled to the gain circuit. The degeneration circuit can include an inductor and a switching-capacitive arm coupled in parallel to the inductor. The degeneration circuit can operate based on a current gain mode to change an inductance for the variable-gain amplifier.

A modulated signal generating device for modulating includes a first amplifier that generates a first amplified signal based on a first control signal; a second amplifier that has a smaller amplification factor as compared to the first amplifier and that generates a second amplified signal based on a second control signal; a combiner that combines the first amplified signal and the second amplified signal and generates a modulated signal; a first control unit that generates the first control signal based on a first component signal included in a input signal; a first filter that eliminates the harmonic component included in a first difference signal, which represents the difference between the input signal and the first component signal, and generates a first filtered signal; and a second control unit that generates the second control signal based on a second component signal included in the first filtered signal.

A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a first power amplifier disposed on the first principal surface and configured to amplify a transmission signal in a first frequency band; a second power amplifier disposed on the first principal surface and configured to amplify a transmission signal in a second frequency band different from the first frequency band; and a switch disposed on the second principal surface and connected to an output terminal of the first power amplifier and an output terminal of the second power amplifier.

A module substrate has first and second main surfaces that on opposite sides of the module substrate, a resin member that covers the second main surface, and a plurality of post electrodes that are spaced apart from each other on the second main surface and penetrate through the resin member from the second main surface. The plurality of post electrodes includes a first post electrode and a first recess recessed toward the second main surface and formed in at least part of a region of the surface of the resin member that surrounds a leading end part of the first post electrode.