Abstract: Apparatus and methods for signal conditioning of radio frequency signals are provided. In certain embodiments, a mobile device includes a transceiver configured to output a differential transmit signal and to receive a single-ended receive signal, and a front end system. The front end system includes a transmit balun, a differential transmit amplifier configured to amplify the differential transmit signal to generate an amplified differential transmit signal provided to a first winding of the transmit balun, a differential receive amplifier configured to amplify a differential receive signal received from the first winding to generate an amplified differential receive signal, and a receive balun configured to convert the amplified differential receive signal into the single-ended receive signal.

Abstract: Apparatus and methods for power amplifier power management are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a radio frequency signal, a front-end system including a first power amplifier module that amplifies the radio frequency signal, and a power management system including an envelope tracking power management unit that provides an envelope tracking supply voltage to the first power amplifier module, and a first average power tracking power management unit that provides an average power tracking supply voltage to the first power amplifier module. The first power amplifier module is configured to selectively switch between the envelope tracking supply voltage and the average power tracking supply voltage.

Abstract: Power amplifiers with supply capacitor switching are provided herein. In certain configurations, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, a power management circuit that controls a voltage level of a supply voltage of the power amplifier, a supply capacitor, and a silicon-on-insulator (SOI) switch in series with the supply capacitor between the supply voltage and the a reference voltage, such as ground. The power management circuit is operable in multiple supply control modes including, for example, an average power tracking (APT) mode and an envelope tracking (ET) mode. Additionally, the SOI switch is controlled based on the supply control mode of the power management circuit.

Abstract: Apparatus and methods for wirelessly communicating using antennas are disclosed. In certain embodiments, an antenna system includes a first radio frequency signal conditioning circuit configured to condition a first radio frequency signal of a first frequency, a plurality of second radio frequency signal conditioning circuits configured to condition a plurality of second radio frequency signals of a second frequency that is greater than the first frequency, a plurality of switches operable in a first mode and a second mode, and an antenna array of including a plurality of antenna elements interconnect by the plurality of switches. The antenna array is operable to handle the first radio frequency signal in the first mode, and to handle the plurality of second radio frequency signals in the second mode.

Abstract: Methods, systems and devices are disclosed for performing a semiconductor processing operation. In some embodiments this includes configuring a wire bonding machine to perform customized movements with a capillary tool of the wire bonding machine, etching bulk contaminants over one or more locations of a semiconductor device with the capillary tool, and applying plasma to the semiconductor device to remove residual contaminants.

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 tracking and rejection filter for use in a receiver of a radio includes a selectable filter configured to provide an output digital in-phase signal and an output digital quadrature signal based on a center frequency, a digital in-phase signal corresponding to an in-phase component of a received radio frequency signal, and a digital quadrature signal corresponding to a quadrature component of the received radio frequency signal. The tracking and rejection filter includes a select circuit configured to select the center frequency of the selectable filter according to whether an interfering signal is detected in a target frequency band of the received radio frequency signal. The center frequency is selected from a predetermined frequency and an estimated center frequency determined using an instantaneous frequency signal. The instantaneous frequency signal is based on the digital in-phase signal and the digital quadrature signal.

Abstract: Transition smoothing apparatus for reducing spurious input to a system under feedback control connected to a control loop. The apparatus includes a loop filter to integrate an error between an input signal applied to the loop filter and an output signal of the system under feedback control, an analog-to-digital converter to provide digitized integrated error values, a controller to generate output values supplied to the system under feedback control in response to the digitized integrated error values and in a start-up sequence to control a feedback digital-to-analog converter according to the digitized integrated error values to supply a first control signal to the loop filter and control the system under feedback control to generate a second control signal, and an alignment detector to detect phase alignment between the first control signal and the second control signal to control a smooth transition into closed loop operation of the control loop.

Abstract: Methods and systems for fast sounding reference symbol (SRS) antenna port switching for FDD. A mobile device can include a baseband processor and a front end including a transmit power amplifier, a first transmit path, and a second transmit path. The front end can be configurable in a first mode to transmit via the first transmit path within a transmit band of a frequency division duplex band. The front end can be further configurable in a second mode to transmit via the second transmit path within a receive band of the frequency division duplex band.

Abstract: A piezoelectric MEMS microphone includes a substrate and a piezoelectric sensor movably coupled to the substrate. The piezoelectric sensor includes a multilayer cantilever beam with multiple piezoelectric layers and multiple metal electrode layers. The beam is attached to the substrate and extends to a distal tip at a free unsupported end. A feedback control circuit is electrically connected to one or more of the metal electrode layers and applies a direct current bias voltage between at least two of the metal electrode layers to actively control an acoustic resistance of the piezoelectric sensor.

Abstract: Multi-band RF front-end modules, and wireless devices incorporating same, having a multi-feed antenna system and a plurality of dedicated antenna feed paths, each directly connected to the multi-feed antenna system and assigned to a different frequency band.

Abstract: Apparatus and methods for antenna arrays with staggered rows of antennas for dual frequency operation are provided. In certain embodiments, a mobile device includes a front-end system including a plurality of radio frequency signal conditioning circuits, an antenna array that includes a plurality of antenna elements including a first row of antenna elements and a second row of antenna elements that are staggered, a plurality of switches coupled between the plurality of radio frequency signal conditioning circuits and the antenna array, and a control circuit configured to control a selection of the plurality of antenna elements by the plurality of switches.

Abstract: Apparatus and methods for power amplifier power management are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a radio frequency signal, a front-end system including a first power amplifier module that amplifies the radio frequency signal, and a power management system including an envelope tracking power management unit that provides an envelope tracking supply voltage to the first power amplifier module, and a first average power tracking power management unit that provides an average power tracking supply voltage to the first power amplifier module. The first power amplifier module is configured to selectively switch between the envelope tracking supply voltage and the average power tracking supply voltage.

Abstract: A packaged acoustic wave filter component can include an acoustic wave device including a first piezoelectric layer and an interdigital transducer electrode on the first piezoelectric layer. A support layer may be included over the acoustic wave device, and the packaged hybrid filter component can also include a bulk acoustic wave resonator over the support layer. A cap layer may extend over and encapsulate the bulk acoustic wave resonator. One or more external vias may extend through the support layer and the underlying layers of the acoustic wave device to provide electrical communication with the packaged bulk acoustic wave generator.

Abstract: Systems, methods, and devices relate to tunable circuits for multimode power amplification. For example, a variable-gain amplification system can include an amplifier configured to provide an amplified signal and to selectively operate in at least a first gain mode and a second gain mode. The variable-gain amplification system can also include a tunable circuit configured to receive the amplified signal from the amplifier and to provide an output signal. The tunable circuit can be configured to implement a first turn ratio for the first gain mode and a second turn ratio for the second gain mode.

Abstract: Acoustic wave devices and related methods are disclosed. In some embodiments, an acoustic wave device can include a quartz substrate having a first surface, and a piezoelectric plate formed from LiTaO3 or LiNbO3 and having a first surface configured to support a surface acoustic wave and a second surface in engagement with the first surface of the quartz substrate. The second surface of the piezoelectric plate is a minus surface resulting from crystal structure orientation of the piezoelectric plate. The acoustic wave device can further include an interdigital transducer electrode formed on the first surface of the piezoelectric plate and configured to provide transducer functionality associated with the surface acoustic wave.

Abstract: Methods and assemblies related to fabrication of acoustic wave devices. In some embodiments, a method for fabricating an acoustic wave device can include attaching a first surface of a piezoelectric layer, such as a LiTaO3 or LiNbO3 layer, to a handling substrate, and performing a thinning operation on the piezoelectric layer to expose a second surface of a reduced-thickness piezoelectric layer attached to the handling substrate. The method can further include bonding the second surface of the reduced-thickness piezoelectric layer to a first surface of a permanent substrate, and removing the handling substrate from the reduced-thickness piezoelectric layer. The handling substrate can be, for example, a silicon substrate, and the permanent substrate can be, for example, a quartz substrate.

Abstract: A power amplifier can include an input stage that includes an amplifying transistor having an input node and an output node, such that a signal at the input node has a first power level and an amplified signal at the output node has a second power level. The power amplifier can further include a bias circuit configured to provide a bias signal to the amplifying transistor, and a feedback circuit that couples the output node of the amplifying transistor to the input node of the amplifying transistor. The feedback circuit can include a resistance and a capacitance arranged in series. The power amplifier can further include a gain compensation circuit implemented relative to the input stage such that the second power level is compensated for a variation in temperature associated with the power amplifier.

Abstract: Systems and methods for differential antenna driving are provided. In one aspect, a front end system includes at least one power amplifier configured to receive a first transmit radio frequency signal from a baseband processor, amplify the first transmit radio frequency signal, and output the amplified first transmit radio frequency signal. The front end system further includes at least one balun configured to receive the amplified first transmit radio frequency signal. The at least one balun includes a positive output coupled to a first monopole of at least one antenna and a negative output coupled to a second monopole of the at least one antenna.

Abstract: In some embodiments, a compensated power detector can include a power detector that includes a first detection cell having a bias input and an output, and a second detection cell having a signal input, a bias input and an output. The power detector can further include an error amplifier having a first input coupled to the output of the first detection cell, and a second input for receiving a reference voltage. The error amplifier can be configured to provide an output voltage to each of the bias inputs of the first and second detection cells, such that an output of the second detection cell is representative of power of a radio-frequency signal received at the signal input with an adjustment for one or more non-signal effects as measured by the first detection cell and the error amplifier.