Abstract: Switchable base feed circuit for radio-frequency (RF) power amplifiers. In some embodiments, an RF power amplifier (PA) circuit can include a transistor having a base, a collector, and an emitter, with the transistor being configured to amplify an RF signal. The PA circuit can further include a bias circuit configured to provide a base bias signal to the base of the transistor. The PA circuit can further include a switchable base feed circuit implemented between the bias circuit and the base of the transistor. The switchable base feed circuit can be configured to provide a plurality of different resistance values for the base bias signal between the bias circuit and the base of the transistor. Such a PA circuit can be implemented in products such as a die, a module, and a wireless device.

Abstract: Aspects of this disclosure relate to dynamic error vector magnitude (DEVM) compensation. In one embodiment, an apparatus includes an amplifier, a low pass filter, and a bias circuit. The amplifier, such as a power amplifier, can amplify an input signal. The low pass filter, such as an integrator, can generate a correction signal based at least partly on an indication of a duty cycle of the amplifier. The indication of the duty cycle of the amplifier can be an enable signal for the amplifier, for example. The bias circuit can generate a bias signal based at least partly on the correction signal and provide the bias signal to the amplifier to bias the amplifier.

Abstract: Systems, devices and methods related to diversity receivers. In some embodiments, a receiving system can include a controller configured to selectively activate one or more of a plurality of paths between an input and an output, and a plurality of amplifiers, with each one of the plurality of amplifiers disposed along a corresponding one of the plurality of paths and configured to amplify a signal received at the amplifier. The receiving system can further include two or more of features including (a) variable-gain amplifiers, (b) phase-shifting components, (c) impedance matching components, (d) post-amplifier filters, (e) a switching network, and (f) flexible band routing. In some embodiments, such a receiving system can be implemented as a diversity receive (DRx) module.

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: Systems and methods are disclosed for integrating functional components of front-end modules for wireless radios. Front-end modules disclosed may be dual-band front-end modules for use in 802.11ac-compliant devices. In certain embodiments, integration of front-end module components on a single die is achieved by implementing a high-resistivity layer or substrate directly underneath, adjacent to, and/or supporting SiGe BiCMOS technology elements.

Abstract: Diversity receiver front end system with flexible band routing. A receiving system can include a plurality of amplifiers, each one of the plurality of amplifiers disposed along a corresponding one of a plurality of paths between an input of the receiving system and an output of the receiving system and configured to amplify a radio-frequency (RF) signal received at the amplifier. The receiving system can further include an input multiplexer configured to receive one or more RF signals at one or more input multiplexer inputs and to output each of the one or more RF signals to one or more of a plurality of input multiplexer outputs to propagate along a respective one or more of the plurality of paths.

Abstract: Devices and methods related to embedded sensors for dynamic error vector magnitude corrections. In some embodiments, a power amplifier (PA) can include a PA die and an amplification stage implemented on the PA die. The amplification stage can include an array of amplification transistors, with the array being configured to receive and amplify a radio-frequency (RF) signal. The PA can further include a sensor implemented on the PA die. The sensor can be positioned relative to the array of amplification transistors to allow sensing of an operating condition representative of at least some of the amplification transistors. The sensor can be substantially isolated from the RF signal.

Abstract: Radiofrequency and other electronic devices can be formed from textured hexaferrite materials, such as Z-phase barium cobalt ferrite Ba3Co2Fe24O41 (Co2Z) having enhanced resonant frequency. The textured hexaferrite material can be formed by sintering fine grain hexaferrite powder at a lower temperature than conventional firing temperatures to inhibit reduction of iron. The textured hexaferrite material can be used in radiofrequency devices such as circulators or telecommunications systems.

Abstract: A linearization circuit reduces intermodulation distortion in a differential amplifier that includes a first stage and a second stage. The linearization circuit receives a first signal that includes a first frequency and a second frequency and generates a difference signal having a frequency approximately equal to the difference of the first frequency and the second frequency, generates an envelope signal based at least in part on a power level of the first signal, and adjusts a magnitude of the difference signal based on the envelope signal. When the differential amplifier receives the first signal at an input terminal, the first stage receives the adjusted signal, and the second stage does not receive the adjusted signal, intermodulation between the adjusted signal and the first signal cancels at least a portion of the intermodulation between the first frequency and the second frequency from the output of the differential amplifier.

Abstract: Disclosed herein are power amplification (PA) systems configured to amplify a signal, such as a radio-frequency signal. The PA system includes a plurality of power amplifiers that are configured to amplify a signal received at a signal input and to output the amplified signal at a signal output. The power amplifiers are configured to receive a supply voltage that is a combination of a battery voltage and an envelope tracking signal. The PA system includes a PA controller configured to control the power amplifiers based at least in part on the battery voltage or a power output of the power amplifiers. The PA controller can be configured to alter impedance matching components of the PA system to reconfigure a load line of the power amplifiers.

Abstract: Circuits and devices related to compensated power detectors. In some embodiments, a power amplifier can include an amplification stage configured to receive a signal at an input and provide an amplified signal at an output, and a detector coupled to the output of the amplification stage and configured to generate a slow-varying or direct-current signal as an input signal representative of power associated with the amplified signal. The detector can be further configured to generate an output signal based on the input signal and a compensation signal resulting from a combination of a first current representative of the input signal and a second current representative of an operating condition associated with the power amplifier.

Abstract: A coupler is presented that has high-directivity and low coupling coefficient variation. The coupler includes a first trace with a first edge substantially parallel to a second edge and substantially equal in length to the second edge. The first trace includes a third edge substantially parallel to a fourth edge. The fourth edge is divided into three segments. The outer segments are a first distance from the third edge. The middle segment is a second distance from the third edge. Further, the coupler includes a second trace, which includes a first edge substantially parallel to a second edge and substantially equal in length to the second edge. The second trace includes a third edge substantially parallel to a fourth edge. The fourth edge is divided into three segments. The outer segments are a first distance from the third edge. The middle segment is a second distance from the third edge.

Abstract: An RF power amplifier biasing circuit has a start ramp signal input, a main current source input, an auxiliary current source input, and a circuit output. A ramp-up capacitor is connected to the auxiliary current source input. A ramp-up switch transistor is connected to the start ramp signal input and is selectively thereby to connect the auxiliary current source input to the ramp-up capacitor. A buffer stage has an input connected to the ramp-up capacitor and an output connected to the main current source input at a sum node. A mirror transistor has a gate terminal corresponding to the circuit output and a source terminal connected to the sum node and to the gate terminal.

Abstract: Diversity receiver front end system with flexible antenna routing. A receiving system can include a plurality of amplifiers. Each one of the plurality of amplifiers can be disposed along a corresponding one of a plurality of paths between an input of the receiving system and an output of the receiving system. Each one of the plurality of paths can correspond to a different frequency band. The receiving system can include an input multiplexer configured to receive, at one or more of a plurality of input multiplexer inputs, one or more RF signals. Each one of the one or more RF signals can include one or more frequency bands. The input multiplexer can be configured to output each of the one or more RF signals to one or more of a plurality of input multiplexer outputs.

Abstract: Field effect transistor stacks include a first field-effect transistor having a source finger, a drain finger, and a gate finger interposed therebetween, the source finger and the drain finger of the first field-effect transistor being separated by a first drain-to-source distance, and a second field-effect transistor in a series connection with the first field-effect transistor, the second field-effect transistor having a source finger, a drain finger, and a gate finger interposed therebetween, the source finger and the drain finger of the second field-effect transistor being separated by a second drain-to-source distance that is different than the first drain-to-source distance.

Abstract: A power amplification system includes a Doherty power amplifier (PA) configured to receive a voltage supply signal and a radio-frequency (RF) signal and generate an amplified RF signal using the voltage supply signal, the Doherty PA including a carrier amplifier and a peaking amplifier. A carrier amplifier bias circuit and a peaking amplifier bias circuit coupled to one or more of the carrier amplifier and the carrier amplifier bias circuit over a coupling path are provided wherein the peaking amplifier bias circuit is configured to provide a peaking bias signal to the peaking amplifier based on a saturation level of the carrier amplifier.

Abstract: Described herein are circuits and methods for improving switch performance when overdriving the gate by adding a delay on a PMOS gate voltage such that it can turn on the PMOS during switch state transition to allow charge/discharge of the switch body voltage faster and it can turn off once the process is complete. For example, back-to-back diodes can be used to separate the PMOS gate and drain. This can reduce leakage current and can reduce or eliminate the potential for breakdown of the switch.

Abstract: Disclosed are devices and methodologies for cleaning wafers in wafer processing operations such as solvent cleaning. In an example situation, a wafer that has been separated from a support plate can be cleaned. The wafer still needs to be handled carefully during such a cleaning operation. Various devices and methodologies that facilitate efficient handling of wafers and solvent cleaning operations are disclosed.

Abstract: Circuits and methods related to power amplifiers. In some implementations, a bias circuit includes a reference device connectable to receive a first electrical supply level, the reference device arranged to produce an electrical bias condition using the first electrical supply level, and the reference device connectable to provide the electrical bias condition to an amplifier device connectable to a second electrical supply level. The bias circuit also includes a differential amplifier connectable to receive the first electrical supply level, the differential amplifier having a first input connectable to a first node of the reference device and a second input connectable to receive a reference electrical level, the differential amplifier arranged to maintain a first electrical level on the first node of the reference device as a function of the reference electrical level.

Abstract: Doherty power amplifier combiner with tunable impedance termination circuit. A signal combiner can include a balun transformer circuit having a first coil and a second coil. The first coil can be implemented between a first port and a second port. The second coil can be implemented between a third port and a fourth port. The first port and the third port can be coupled by a first capacitor. The second port and fourth port can be coupled by a second capacitor. The first port can be configured to receive a first signal. The fourth port can be configured to receive a second signal. The second port can be configured to yield a combination of the first signal and the second signal. The signal combiner can include a termination circuit that couples the third port to a ground. The termination circuit can include a tunable impedance circuit.