Abstract: Systems and methods related to power amplification and power supply control. A power amplification control system can include an interface configured to receive a transceiver control signal from a transceiver. The power amplification control system can include a power amplifier control component configured to generate a power amplifier control signal based on the transceiver control signal from the transceiver and a power supply control component configured to generate a power supply control signal based on the transceiver control signal from the transceiver and to generate the power supply control signal based on a local control signal from the power amplifier control component.

Abstract: Aspects of this disclosure relate to an acoustic wave filter with an acoustic wave resonator arranged to concentrate a transverse spurious mode at a frequency. Such an acoustic wave resonator can have a narrow aperture to concentrate the transverse spurious mode. The transverse spurious mode can increase steepness of a skirt of the acoustic wave filter. Related methods, acoustic wave devices, multiplexers, radio frequency front ends, radio frequency modules, and wireless communication devices are disclosed.

Abstract: A baseline difference is determined between a slave line card time stamp corresponding to a slave line card frame sync signal and a master line card time stamp corresponding to a master line card frame sync signal. The slave line card generates subsequent slave line card time stamps for subsequent slave line card frame sync signals and the master line card generates subsequent master line card time stamps for subsequent master line card frame sync signals. Current differences are determined between subsequent slave line card time stamps and the subsequent master line card time stamps and the current differences are compared to the baseline difference. When a mismatch difference occurs (current difference differs from the baseline difference), the mismatch difference causes a phase-locked loop in the master line card to be adjusted or an offset to be provided to the master line card time of day counter.

Abstract: Aspects of this disclosure relate to an impedance transformation circuit for use in an amplifier, such as a low noise amplifier. The impedance transformation circuit includes a matching circuit including a first inductor. The impedance transformation circuit also includes a second inductor. The first and second inductors are magnetically coupled to each other to provide negative feedback to linearize the amplifier.

Abstract: Disclosed herein are embodiments of an enhanced resonant frequency hexagonal ferrite material and methods of manufacturing. The hexagonal ferrite material can be Y-phase hexagonal ferrite material, such as those including strontium. In some embodiments, oxides consistent with the stoichiometry of Sr3Co2Fe24O41, SrFe12O19 or CoFe2O4 can be used form an enhanced hexagonal ferrite material.

Abstract: A reconfigurable triplexer that can support more frequency bands than a traditional triplexer is disclosed. For example, the reconfigurable triplexer can handle frequencies of several hundred megahertz up to 10 gigahertz. Further, certain implementations of the reconfigurable multiplexer can reduce or eliminate frequency dead zones that exist with traditional multiplexers. The reconfigurable triplexer includes a multi-stage filter bank capable of supporting a number of frequency bands and a bypass circuit that enables the triplexer to support a variety of sets of frequencies. For instance, unlike traditional triplexers, the reconfigurable triplexer can support both frequency bands with relatively narrow spacing and frequency bands with relatively wide spacing. Further, the inclusion of the bypass circuit enables the reduction or elimination of dead zones between supported frequencies.

Abstract: Aspects of this disclosure relate to a surface acoustic wave resonator. The surface acoustic wave resonator includes a piezoelectric substrate, interdigital transducer electrodes disposed on an upper surface of the piezoelectric substrate, a dielectric temperature compensation layer disposed on the piezoelectric substrate to cover the interdigital transducer electrodes, and a dielectric passivation layer over the temperature compensation layer. The passivation layer may include an oxide layer configured to have a sound velocity greater than that of the temperature compensation layer to suppress a transverse signal transmission.

Abstract: A method for controlling a high-power drive device includes providing a current having a first predetermined current level to an output node during a first phase of a multi-phase turn-on process for the high-power drive device coupled to the output node. The method includes transitioning from the first phase to a second phase of the multi-phase turn-on process based on a first indication of a sensed voltage level on the output node during the first phase and a second indication of a time elapsed from a start of the first phase during the first phase. The method includes providing the current having a second predetermined current level to the output node during the second phase.

Abstract: Aspects of this disclosure relate to a radio frequency module with a radio frequency coupler and a coupler switching circuit. The coupler switching circuit can provide an indication of radio frequency power generated by the radio frequency coupler to a first input/output port. The coupler switching circuit can also pass an indication of radio frequency power received at the first input/output port to a second input/output port, and pass an indication of radio frequency power received at the second input/output port to the first input/output port.

Abstract: Front end systems and related devices, integrated circuits, modules, and methods are disclosed. One such packaged module includes a multi-mode power amplifier circuit in an interior of a radio frequency shielding structure and an antenna external to the radio frequency shielding structure. The multi-mode power amplifier circuit includes a stacked output stage including a transistor stack of two or more transistors. The multi-mode power amplifier circuit also includes a bias circuit configured to control a bias of at least one transistor of the transistor stack based on a mode of the multi-mode power amplifier circuit. The radio frequency shielding structure can extend above a package substrate. The antenna can be on the package substrate. Other embodiments of front end systems are disclosed, along with related devices, integrated circuits, modules, methods, and components thereof.

Abstract: A shared bus time interleaves 1 PPS signal and control and coordination information between a primary timing source and line cards that need to be synchronized using the 1 PPS signals. The shared bus utilizes 1 second frames divided into time slots. The 1 PPS signals are interleaved at predetermined locations in the frame so the delays introduced by interleaving the 1 PPS data in time can be precisely removed. While the bus is not being used for 1 PPS signals, the bus is available to send control and coordination information between the line cards and the primary timing source, avoiding the use of another system and increasing utilization of an available communication path.

Abstract: Circuits, systems, devices, and methods related to transistors with Schottky barriers are discussed herein. For example, a method of fabricating a transistor can include forming a p-well or an n-well in a substrate and forming a gate for the transistor. The method can also include doping a region within the p-well or n-well with a concentration below a threshold and forming a conductor layer on the doped region.

Abstract: Methods of manufacturing an acoustic wave device are disclosed. An anti-reflection layer can be formed over a conductive layer that is over a piezoelectric layer. The conductive layer can include aluminum, for example. The anti-reflection layer can remain distinct from the conductive layer after a heating process. A photolithography process can pattern an interdigital transducer of the acoustic wave device from one or more interdigital transducer electrode layers that include the conductive layer. The anti-reflection layer can reduce reflection from the conductive layer during the photolithography process.

Abstract: Remote compensators for mobile devices are provided. In certain embodiments, a remote compensator includes a first balun, a cable-side circulator including an output that provides a transmit signal and an input that receives an amplified receive signal, a first phase shifter, a second phase shifter, a first antenna-side circulator, a second antenna-side circulator, a push-pull amplifier, and a receive amplifier that generates the amplified receive signal by amplifying a first receive signal from the first antenna-side circulator and a second receive signal from the second antenna-side circulator. The push-pull amplifier includes an input that receives the transmit signal, a first output connected to a first end of a winding of the first balun through the first antenna-side circulator and the first phase shifter, and a second output connected to a second end of the winding of the first balun through the second phase shifter and the second antenna-side circulator.

Abstract: A method for fabricating a semiconductor die is provided. The method can include providing a semiconductor substrate, forming a set of field-effect transistors on the semiconductor substrate, each field-effect transistor in the set of field-effect transistors having a respective source, drain, gate, and body, forming a compensation circuit on the semiconductor substrate, and connecting the compensation circuit to the set of field-effect transistors in parallel, the compensation circuit configured to compensate a non-linearity effect generated by the set of field-effect transistors.

Abstract: Composite cascode power amplifiers for envelope tracking applications are provided herein. In certain embodiments, an envelope tracking system includes a composite cascode power amplifier that amplifies a radio frequency (RF) signal and that receives power from a power amplifier supply voltage, and an envelope tracker that generates the power amplifier supply voltage based on an envelope of the RF signal. The composite cascode power amplifier includes an enhancement mode (E-MODE) field-effect transistor (FET) for amplifying the RF signal and a depletion mode (D-MODE) FET in cascode with the E-MODE FET.

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 spur measurement system uses a first device with a spur cancellation circuit that cancel spurs responsive to a frequency control word identifying a spurious tone of interest. A device under test generates a clock signal and supplies the clock signal to the first device through an optional divider. The spur cancellation circuit in the first device generates sine and cosine weights at the spurious tone of interest as part of the spur cancellation process. A first magnitude of the spurious tone in a phase-locked loop in the first device is determined according to the sine and cosine weights and a second magnitude of the spurious tone in the clock signal is determined by the first magnitude divided by gains associated with the first device.

Abstract: Aspects of this disclosure relate to an acoustic wave resonator with hyperbolic mode suppression. The acoustic wave resonator can include a piezoelectric layer, an interdigital transducer electrode, a temperature compensation layer, and a mass loading strip. The mass loading strip can be a conductive strip. The mass loading strip can overlap edge portions of fingers of the interdigital transducer electrode. A layer of the mass loading strip can have a density that is at least as high as a density of a material of the interdigital transducer electrode. The material of the interdigital transducer can impact acoustic properties of the acoustic wave resonator.

Abstract: Apparatus and methods for envelope alignment calibration in radio frequency (RF) systems are provided. In certain embodiments, calibration is performed by providing an envelope signal that is substantially triangular along an envelope path, and by providing an RF signal to a power amplifier along an RF signal path. Additionally, an output of the power amplifier is observed to generate an observation signal using an observation receiver. The observation signal includes a first peak and a second peak, and a delay between the envelope signal and the RF signal is controlled based on relative size of the peaks of the observation signal to one another.