Abstract: Aspects of this disclosure relate to a multiplexer that includes an acoustic wave filter including acoustic wave resonators on at least two die with a transmission line electrically connecting the acoustic wave resonators on the two die. The acoustic wave filter can include a plurality of acoustic wave resonators on a first die electrically connected to at least one acoustic wave resonator on a second die via the transmission line. The acoustic wave resonator on the second die can provide a relatively high impedance at a respective passband of one or more other filters of the multiplexer. This can reduce effects of the transmission line of the acoustic wave filter on a respective passband of one or more other filters of the multiplexer.

Abstract: Methods related to controlling switches. In some embodiments, a method for controlling a radio-frequency switch can include providing or generating a control signal to allow generation of a plurality of reference levels by a regulator, or to allow the regulator to be in sleep mode. The method can further include operating the regulator based on the control signal to generate the plurality of reference voltage levels for operation of the radio-frequency switch, or to be in the sleep mode.

Abstract: A semiconductor die includes a substrate layer, one or more metal layers disposed over the substrate layer, and a pair of polyimide layers disposed over the substrate so that they define an interface therebetween. One or both of the pair of polyimide layers have a trench that separates the interface from the one or more metal layers. The trench can be formed by etching the polyimide layer(s). A topcoat insulation layer is disposed over the one or more metal layers and polyimide layers. The topcoat insulation layer is impervious to moisture and the trench inhibits migration of moisture along the interface to the one or more metal layers, thereby preventing metal migration from the one or more metal layers along the interface.

Abstract: Disclosed herein are ceramic materials, such as bismuth substituted garnets, which can have high curie temperatures and high dielectric constants. In certain implementations, indium can be incorporated into the ceramic to improve certain properties and to avoid calcium compensation. The ceramic materials disclosed herein can be particular advantageous for below resonance applications.

Abstract: A piezoelectric microelectromechanical systems 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 include a single piezoelectric film layer disposed over the top end of the substrate and defining a diaphragm structure, the single piezoelectric film layer having substantially zero residual stress and formed from a piezoelectric wafer. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when subjected to sound pressure via the opening in the substrate.

Abstract: A method for measuring a received signal includes receiving a differential pair of signals by a differential pair of input nodes of a differential circuit. The method includes attempting to match a first current through a first node of the differential circuit corresponding to the differential pair of signals to a second current through a second node of the differential circuit corresponding to a feedback signal. The method includes generating an output measurement signal based on the first current and the second current. The output measurement signal has a level corresponding to an average amplitude of the differential pair of signals.

Abstract: In some embodiments, a power amplification system can comprise a current source, an input switch configured to alternatively feed current from the current source to a high-power circuit path and a low-power circuit path, and a band switch including a switch arm for switching between a plurality of bands. Each of the high-power circuit path and the low-power circuit path can be connected to the switch arm.

Abstract: Phase shifters for communication systems are provided herein. In certain embodiments, a phase shifter includes a plurality of phase shifting sections and a plurality of selection switches each coupled to a corresponding one of the phase shifting sections. The selection switches are formed on a semiconductor die, and are operable to connect one or more selected phase shifting sections between an input terminal and an output terminal, thereby controlling an overall phase shift provided by the phase shifter.

Abstract: Aspects of this disclosure relate to a radio frequency system with tunable notch filtering. The radio frequency system includes a first tunable filter and a second tunable filter. The first tunable filter is coupled between an output of a power amplifier and a radio frequency switch. The second tunable filter includes mutually coupled inductors and a tunable impedance circuit electrically connected to at least one of the mutually coupled inductors. The second tunable filter is coupled between an antenna switch and an antenna node. Related methods and wireless communication devices are also disclosed.

Abstract: Configuration devices in a module. In some embodiments a radio-frequency module includes a serial bus including a first serial data line and a second serial data line. The radio-frequency module also includes a control component coupled to the serial bus and the first switch, the control component configured to determine whether first data is detected on the first serial data line, determine whether second data is detected on the second serial data line, and decode a command based on the first data and second data when the first data is detected on the first serial data line and when the second data is detected on the second serial data line.

Abstract: A method for regulating a voltage reference signal includes providing a first output current during a first interval and a boosted output current during a second interval to generate a low-dropout voltage reference signal based on a first power supply voltage, a second power supply voltage, and a reference voltage level. The method includes, during the second interval, compensating for a voltage drop caused by providing the boosted output current. The first output current may be provided in a first mode of operation. The boosted output current and voltage drop compensation may be provided in a boosted mode of operation.

Abstract: An acoustic wave device that includes a spinel layer, a 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 ?. The piezoelectric layer can have a thickness than is less than ?. In some embodiments, the acoustic wave device can include a temperature compensating layer that is disposed between the piezoelectric layer and the spinel layer.

Abstract: A technique for powering gate drivers in a half-bridge configuration uses a single external power supply to power each gate driver. A single on-chip regulator regulates the positive turn-on voltage for each switch. The regulator overhead, is also used as the negative voltage for turn-off, thus transferring the low-frequency variation of the external power supply to the negative turn-off voltage. Accordingly, a single on-chip regulator generates both the positive turn-on voltage and the negative turn-off voltage. In at least one embodiment, reuse of the switch turn-off current further reduces on-chip power dissipation. The on-chip regulator's output filter capacitor discharges during turn-on of the external power switching device. During turn-off, the current that discharges the switch gate capacitance recharges the regulator filter capacitor.

Abstract: Multi-mode broadband low noise amplifiers (LNAs) are disclosed herein. In certain embodiments, an LNA includes a first amplification stage and a second amplification stage having a lower gain than the first amplification stage. The LNA is operable in a plurality of operating modes including a first mode in which the first amplification stage and the second amplification stage operate in a cascade to amplify a radio frequency (RF) receive signal, and a second mode in which the first amplification stage amplifies the RF receive signal and the second amplification stage is bypassed.

Abstract: A supply-glitch-tolerant voltage regulator includes a regulated voltage node and an output transistor having a source terminal, a gate terminal, and a drain terminal. The source terminal is coupled to the regulated voltage node. The supply-glitch-tolerant voltage regulator includes a first current generator coupled between a first node and a first power supply node. The supply-glitch-tolerant voltage regulator includes a second current generator coupled between the first node and a second power supply node. The supply-glitch-tolerant voltage regulator includes a feedback circuit coupled to the first current generator and the second current generator and is configured to adjust a voltage on the first node based on a reference voltage and a voltage level on the regulated voltage node. The supply-glitch-tolerant voltage regulator includes a diode coupled between the drain terminal and the first power supply node and a resistor coupled between the gate terminal and the first node.

Abstract: Methods related to radio-frequency (RF) filters on silicon-on-insulator (SOI) substrate. In some embodiments, a method of manufacturing a radio-frequency device can include providing a semiconductor die including a radio-frequency circuit, a first side and a second side, and a plurality of vias, each via configured to provide an electrical connection between the first side and the second side of the semiconductor die. The method can further include mounting a filter device on the first side of the semiconductor die, the filter device in communication with the radio-frequency circuit, the radio-frequency circuit implemented in a layer on the first side of the semiconductor die and at least some of the vias coupled with the radio-frequency circuit to support an electrical connection between the radio-frequency circuit and mounting features on the second side of the semiconductor die.

Abstract: A semiconductor-on-insulator die can include a power amplifier configured to amplify a radio frequency input signal having a fundamental frequency. The die can further include an output matching circuit including first and second second-order harmonic rejection circuits configured to resonate at about two times the fundamental frequency and a third order harmonic rejection circuit configured to resonate at about three times the fundamental frequency.

Abstract: Devices and methods for layout-dependent voltage handling improvement in switch stacks. In some embodiments, a switching device can include a first terminal and a second terminal, a radio-frequency signal path implemented between the first terminal and the second terminal, and a plurality of switching elements connected in series to form a stack between the second terminal and ground. The stack can have an orientation relative to the radio-frequency signal path, and the switching elements can have a non-uniform distribution of a first parameter based in part on the orientation of the stack.

Abstract: Aspects of this disclosure relate to a radio frequency system with a plurality of radio frequency modules. At least one of these radio frequency modules includes a coupler switching circuit that can pass an indication of radio frequency power received at a 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: A radio frequency (RF) switch arrangement that improves the voltage handling capacity of a stack of switching elements (e.g., field-effect transistors (FETs)). The RF switch arrangement can include a ground plane and a stack arranged in relation to the ground plane, the stack including a plurality of switching elements coupled in series with one another. The RF switch arrangement can also include a plurality of capacitive elements, each of the plurality of capacitive elements providing a capacitive path across respective terminals of a corresponding one of the plurality of switching elements.