Abstract: A clamping circuit comprises a first field-effect transistor (FET) having a gate, a source, and a drain, a diode, a first voltage source, and coupling circuitry configured to couple the first voltage source to the drain of the first FET and the diode to the source of the first FET.

Abstract: A radio frequency front end system can include a first module configured to provide multi-input multi-output (MIMO) receive operations for a first plurality of mid bands and a first plurality of high bands. The first module can be further configured to provide transmit operations for the plurality of mid bands. The first module can include a first node. The radio frequency front end system can include a second module configured to provide transmit and receive operations for a second plurality of mid bands and a second plurality of high bands. The second module can be a power amplifier integrated duplexer (PAiD) module. The second module can include a second node. The first module and the second module can be coupled by a signal path at the first node and the second node, respectively.

Abstract: Acoustic wave resonators are disclosed that include a piezoelectric layer and an interdigital transducer electrode over the piezoelectric layer. The interdigital transducer electrode has a rotation angle and a tilt angle. The rotation angle and the tilt angle can together increase a figure of merit of the acoustic wave device. The rotation angle and the tilt angle can both be non-zero.

Abstract: Disclosed herein are embodiments of low temperature co-fireable barium tungstate materials which can be used in combination with high dielectric materials, such as nickel zinc ferrite, to form composite structures, in particular for isolators and circulators for radiofrequency components. Embodiments of the material can include flux, such as bismuth vanadate, to reduce co-firing temperatures.

Abstract: A piezoelectric microelectromechanical systems diaphragm microphone can be mounted on a printed circuit board. The microphone can include a substrate with an opening between a bottom end of the substrate and a top end of the substrate. The microphone can have two or more piezoelectric film layers disposed over the top end of the substrate and defining a diaphragm structure. Each of the two or more piezoelectric film layers can have a predefined residual stress that substantially cancel each other out so that the diaphragm structure is substantially flat with substantially zero residual stress. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when the diaphragm is subjected to sound pressure via the opening in the substrate.

Abstract: Apparatus and methods for sounding reference signal (SRS) switching are provided. In certain embodiments, transmit path resources of user equipment (UE) are used to reduce or eliminate the impairment of SRS upon transport capacity. Furthermore, the transmit path resources can be used for other purposes, and thus SRS switching time can be reduced by re-using transmit path resources that may be included for other purposes. The teachings herein can be used to achieve SRS switching of 0 ?s, thereby eliminating the impact of switching timing constraints for SRS symbols on transport capacity.

Abstract: The radio frequency front-end systems herein include modules having bandwidth controllable components, such as amplifier and filters. By implementing the modules with bandwidth control, the same module can be used for operation of multiple frequency bands including a first frequency band and a second frequency band. Thus, when implementing features such as carrier aggregation, multiple-input multiple-output (MIMO), and/or sounding resource signaling (SRS) for supporting the multiple frequency bands, the total number of modules used can be reduced and/or additional feature support can be provided compared to an implementation in which each module supports a single frequency band.

Abstract: A packaging substrate can include a first surface and a second opposing surface, the first surface having a mounting region configured to receive electronic components, and electrical contacts formed on the second opposing surface. A saw street region can surround the mounting region and the electrical contacts, a metal layer and a solder mask layer being formed within the saw street region on the second opposing surface, and the solder mask layer being formed over the metal layer. An electronic module can include a packaging substrate including a first surface and a second opposing surface, the first surface including a mounting region. A plurality of electronic components can be mounted on the mounting region. A ground pad can be formed on the second opposing surface of the packaging substrate, the ground pad including a solder mask layer formed thereon, the solder mask layer having a plurality of openings.

Abstract: A delay circuit provides a programmable delay and includes an input selector circuit to select between a loop delay output signal and an input signal. A loop delay circuit provides a loop delay to the input signal and supplies the loop delay output signal. The input signal can be recirculated through the loop delay circuit to extend the range of the delay. The input selector circuit selects the feedback signal during recirculation. A variable delay circuit provides a variable delay to the loop delay output signal after the recirculation is complete and supplies a variable delay output signal. An output selector circuit selects the output of the output selector circuit during the recirculation and selects the variable delay output signal after the recirculation is complete to thereby provide a delayed signal with the delay based on the loop delay, the number of loops of recirculation, and the variable delay.

Abstract: Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker is provided for a power amplifier that amplifies an RF signal. The envelope tracker includes a multi-level switching circuit having an output that provides an output current that changes in relation to an envelope signal indicating an envelope of the RF signal when the envelope tracker is operating in an envelope tracking mode. The multi-level switching circuit includes a multi-level supply (MLS) modulator that receives multiple regulated voltages of different voltage levels, and an MLS control circuit that controls the selection of the MLS modulator over time based on the envelope signal. When transitioning the MLS modulator from selection of one regulated voltage level to another regulated voltage level, the MLS control circuit provides a soft transition to gradually switch the regulated voltage levels.

Abstract: Low noise amplifiers (LNAs) with low noise figure are provided. In certain embodiments, an LNA includes a single-ended LNA stage including an input for receiving a single-ended input signal from an antenna and an output for providing a single-ended amplified signal, a balun for converting the single-ended amplified signal to a differential signal, and a variable gain differential amplification stage for amplifying the differential signal from the balun. Implementing the LNA in this manner provides low noise figure, high gain, flexibility in controlling gain, and less sensitivity to ground/supply impedance.

Abstract: A bridge combiner can be implemented as a coupling circuit that includes a common node and configured to couple the common node to a first group of filters through a first path and to couple the common node to a second group of one or more filters through a second path. The coupling circuit can include a resonator such that an impedance provided by each filter of the first group for a signal in each band of the second group results in the signal being sufficiently excluded from the first path, and such that an impedance provided by each filter of the second group for a signal in each band of the first group results in the signal being sufficiently excluded from the second path.

Abstract: Apparatus and methods for envelope tracking systems with automatic mode selection are provided herein. In certain configurations, a power amplifier system includes a power amplifier configured to provide amplification to a radio frequency signal and to receive power from a power amplifier supply voltage, and an envelope tracker including a signal bandwidth detection circuit configured to generate a detected bandwidth signal based on processing an envelope signal corresponding to an envelope of the radio frequency signal. The envelope tracker further includes a switch bank configured to receive a plurality of regulated voltages, a filter configured to filter an output of the switch bank to generate the power amplifier supply voltage, and a mode control circuit configured to control a filtering characteristic of the filter based on the detected bandwidth signal.

Abstract: An electronic device comprises a first substrate having a first surface bonded to a first surface of a second substrate, one or more acoustic wave devices disposed on the first surface of each of the first substrate and the second substrate, and a thermally conductive layer disposed on a second surface of the first substrate opposite the first surface of the first substrate. The thermally conductive layer has a higher thermal conductivity than a material of which the first substrate is formed to reduce an operating temperature of the first substrate.

Abstract: Radio frequency communication systems with a combined antenna impedance tuning and antenna multiplexing functionality are provided. In certain embodiments, a packaged radio frequency module includes an antenna multiplexer and an antenna impedance tuner. The module can be configured to provide impedance matching between one or more radio frequency front end modules and an antenna. The antenna impedance tuner can supplement antenna tuning provided by an antenna aperture separately connected to the antenna.

Abstract: An architecture can include a first group of filters each configured to support a band such that a first frequency range covers the respective bands, and a second group of one or more filters each configured to support a band such that a second frequency range covers the respective one or more bands. Each filter of the first group can be configured to provide an impedance at or near a short circuit impedance for a signal in each band of the second group, and each filter of the second group can be configured to provide an impedance at or near a short circuit impedance for a signal in each band of the first group. The filters of the first and second groups can be implemented as one or more multiplexers. The architecture can further include a coupling circuit having a common node and configured to couple the common node to the one or more multiplexers through a first path and a second path.

Abstract: A system includes at least one processor and at least one memory storing program instructions that, when executed by the at least one processor, cause the system to send an acoustic ranging transmitter signal between a plurality of calibration reference positions and at least one anchor point, receive an acoustic ranging receiver signal associated with the acoustic ranging transmitter signal and with distances between the plurality of calibration reference positions and the at least one anchor point, and estimate a speed of sound based on the acoustic ranging receiver signal.

Abstract: A system for controlling a high-power drive device includes a fault detection integrated circuit product configured to provide an indication of a fault condition associated with the high-power drive device to a first terminal in a first voltage domain in response to detecting the fault condition in a second voltage domain. The system includes a gate driver controller integrated circuit product configured to drive a second terminal coupled to a control node in a second voltage domain based on a control signal and an enable signal received from a third terminal in the first voltage domain. The second voltage domain is higher than the first voltage domain. The system may include a redundant fault reporting integrated circuit product or an additional fault detection integrated circuit product configured to detect a second fault condition in the second voltage domain that is different from the fault condition.

Abstract: A packaged acoustic wave component is disclosed. The packaged acoustic wave component can include a first acoustic wave resonator that includes a first interdigital transducer electrode that is positioned over a first piezoelectric layer. The packaged acoustic wave component can also include a second acoustic wave resonator including a second interdigital transducer electrode positioned over a second piezoelectric layer. The second piezoelectric layer is bonded to the first piezoelectric layer. The packaged acoustic wave component can further include a stopper structure that is positioned over the first piezoelectric layer. The first stopper structure is positioned above a via and extends through the first piezoelectric layer. The stopper structure is in electrical communication with the first interdigital transducer electrode and includes a material which reflects at least fifty percent of light having a wavelength of 355 nanometers.

Abstract: Components of a power amplifier controller may support lower voltages than the power amplifier itself. As a result, a surge protection circuit that prevents a power amplifier from being damaged due to a power surge may not effectively protect the power amplifier controller. Embodiments disclosed herein present an overvoltage protection circuit that prevents a charge-pump from providing a voltage to a power amplifier controller during a detected surge event. By separately detecting and preventing a voltage from being provided to the power amplifier controller during a surge event, the power amplifier controller can be protected regardless of whether the surge event results in a voltage that may damage the power amplifier. Further, embodiments of the overvoltage protection circuit can prevent a surge voltage from being provided to a power amplifier operating in 2G mode.