Abstract: This disclosure relates to a diffusion barrier layer for a radio frequency (RF) transmission line. The diffusion barrier layer includes a material and has a thickness. The thickness of the diffusion barrier layer is sufficiently small such that an RF signal is allowed to penetrate the diffusion barrier layer. Related RF modules and mobile devices that include an RF transmission line with such a diffusion barrier layer are disclosed.

Abstract: This disclosure relates to a mobile device with a transmission line for a radio frequency (RF) signal. The transmission line includes a bonding layer having a bonding surface, a barrier layer proximate the bonding layer, a diffusion barrier layer proximate the barrier layer, and a conductive layer proximate the diffusion barrier layer. The barrier layer and the diffusion barrier layer are configured to prevent conductive material from the conductive layer from entering the bonding layer. The diffusion barrier layer has a thickness sufficiently small such that a radio frequency signal is allowed to penetrate the diffusion barrier layer and propagate in the conductive layer.

Abstract: This disclosure relates to a radio frequency (RF) transmission line for high performance RF applications. The RF transmission line includes a bonding layer having a bonding surface and configured to receive an RF signal, a barrier layer proximate the bonding layer, a diffusion barrier layer proximate the bonding layer and configured to prevent contaminant from entering the bonding layer, and a conductive layer proximate the diffusion barrier layer. The diffusion barrier layer has a thickness that allows the received RF signal to penetrate the diffusion barrier layer to the conductive layer. The diffusion barrier layer can be a nickel layer.

Abstract: One aspect of this disclosure is a power amplifier module that includes a power amplifier die, a first bonding pad on a conductive trace, and a second bonding pad on a conductive trace. The die includes an on-die passive device and a power amplifier. The first bonding pad is electrically connected to the on-die passive device by a first wire bond. The second bonding pad is in a conductive path between the first bonding pad and a radio frequency output of the power amplifier module. The second bonding pad includes a nickel layer having a thickness that is less than 0.5 um, a palladium layer over the nickel layer, and a gold layer over the palladium layer and bonded to a second wire bond that is electrically connected to an output of the power amplifier. Other embodiments of the module are provided along with related methods and components thereof.

Abstract: One aspect of this disclosure is a power amplifier module that includes a power amplifier die including a power amplifier configured to amplify a radio frequency (RF) signal, the power amplifier including a heterojunction bipolar transistor (HBT) and a p-type field effect transistor (PFET), the PFET including a semiconductor segment that includes substantially the same material as a layer of a collector of the HBT, the semiconductor segment corresponding to a channel of the PFET; a load line electrically connected to an output of the power amplifier and configured to provide impedance matching at a fundamental frequency of the RF signal; and a harmonic termination circuit electrically connected to the output of the power amplifier and configured to terminate at a phase corresponding to a harmonic frequency of the RF signal. Other embodiments of the module are provided along with related methods and components thereof.

Abstract: This disclosure relates to a transmission line for high performance radio frequency (RF) applications. One such transmission line can include a bonding layer configured to receive an RF signal, a barrier layer, a diffusion barrier layer, and a conductive layer proximate to the diffusion barrier layer. The diffusion barrier layer can have a thickness that allows a received RF signal to penetrate the diffusion barrier layer to the conductive layer. In certain implementations, the diffusion barrier layer can be nickel. In some of these implementations, the transmission line can include a gold bonding layer, a palladium barrier layer, and a nickel diffusion barrier layer.

Abstract: One aspect of this disclosure is a power amplifier module that includes a power amplifier; a wire bond pad electrically connected to the power amplifier, the wire bond pad including a nickel layer having a thickness that is less than 0.5 um, a palladium layer over the nickel layer, and a gold layer over the palladium layer; and a conductive trace having a top surface with a plated portion and an unplated portion surrounding the plated portion, the wire bond pad being disposed over the plated portion. Other embodiments of the module are provided along with related methods and components thereof.

Abstract: Apparatus and methods for power amplifiers are disclosed. In one embodiment, a power amplifier circuit assembly includes a power amplifier and an impedance matching network. The impedance matching network is operatively associated with the power amplifier and is configured to provide a load line impedance to the power amplifier between about 6? and about 10?. The impedance matching network includes a fundamental matching circuit and one or more termination circuits, and the fundamental matching circuit and each of the of the one or more termination circuits include separate input terminals for coupling to an output of the power amplifier so as to allow the fundamental matching circuit and each of the one or more termination circuits to be separately tuned.

Abstract: One aspect of this disclosure is a power amplifier module that includes a power amplifier configured to provide a radio frequency signal at an output, an output matching network coupled to the output of the power amplifier and configured to provide impedance matching at a fundamental frequency of the radio frequency signal, and a harmonic termination circuit coupled to the output of the power amplifier. The power amplifier is included on a power amplifier die. The output matching network can include a first circuit element electrically connected to an output of the power amplifier by way of a pad on a top surface of a conductive trace, in which the top surface has an unplated portion between the pad the power amplifier die. The harmonic termination circuit can include a second circuit element. The first and second circuit elements can have separate electrical connections to the power amplifier die. Other embodiments of the module are provided along with related methods and components thereof.

Abstract: Disclosed are devices and methods for improving power added efficiency and linearity of radio-frequency power amplifiers implemented in flip-chip configurations. In some embodiments, a harmonic termination circuit can be provided so as to be separate from an output matching network configured to provide impedance matching at a fundamental frequency. The harmonic termination circuit can be configured to terminate at a phase corresponding to a harmonic frequency of the power amplifier output. Such a configuration of separate fundamental matching network and harmonic termination circuit allows each to be tuned separately to thereby improve performance parameters such as power added efficiency and linearity.

Abstract: One aspect of this disclosure is a power amplifier module that includes a power amplifier configured to amplify a radio frequency (RF) signal and an RF transmission line electrically coupled to an output of the power amplifier. The power amplifier includes a heterojunction bipolar transistor and a p-type field effect transistor, in which a semiconductor portion of the p-type field effect transistor corresponds to a channel includes the same type of semiconductor material as a collector layer of the heterojunction bipolar transistor. The RF transmission line includes a nickel layer with a thickness that is less than 0.5 um, a conductive layer under the nickel layer, a palladium layer over the nickel layer, and a gold layer over the palladium layer. Other embodiments of the module are provided along with related methods and components thereof.

Abstract: Apparatus and methods for phase compensation in power amplifiers are disclosed herein. In certain implementations, a method of phase compensation in a power amplifier includes amplifying a radio frequency signal using a power amplifier that includes an input stage and an output stage, powering a bipolar transistor of the output stage using a power amplifier supply voltage, changing a voltage level of the power amplifier supply voltage, the bipolar transistor having an input reactance that changes in response to the change in the voltage level of the power amplifier supply voltage, and compensating for a variation in a phase delay of the power amplifier arising from the change in the input reactance of the bipolar transistor using a compensation circuit that is electrically connected to an output of the input stage.

Abstract: Apparatus and methods for wideband envelope tracking systems are disclosed herein. In certain implementations, an envelope tracker includes a DC-to-DC converter, a current digital-to-analog converter (DAC), an error amplifier, a feedback circuit, and an AC combiner. The current DAC receives a digital envelope signal, and uses the digital envelope signal to generate an envelope current. The feedback circuit is connected between an output and an inverting input of the error amplifier, and the envelope current is provided to the error amplifier's inverting input. Additionally, the AC combiner generates a power amplifier supply voltage by combining an output of the DC-to-DC converter and an output of the error amplifier.

Abstract: Disclosed are devices and methods for improving power added efficiency and linearity of radio-frequency power amplifiers implemented in flip-chip configurations. In some embodiments, a harmonic termination circuit can be provided so as to be separate from an output matching network configured to provide impedance matching at a fundamental frequency. The harmonic termination circuit can be configured to terminate at a phase corresponding to a harmonic frequency of the power amplifier output. Such a configuration of separate fundamental matching network and harmonic termination circuit allows each to be tuned separately to thereby improve performance parameters such as power added efficiency and linearity.

Abstract: Apparatus and methods for phase compensation in power amplifiers are disclosed herein. In certain implementations, a power amplifier includes an input stage, an output stage, an envelope tracker, and a compensation circuit. The input and output stages are cascaded and amplify an input RF signal to generate an amplified output RF signal. The envelope tracker generates a power amplifier supply voltage for at least the output stage based on an envelope of the input RF signal. The compensation circuit compensates for changes in input impedance of the output stage associated with changes in the voltage level of the power amplifier supply voltage. By including the compensation circuit, a variation in the power amplifier's phase delay versus input power can be reduced, thereby leading to an improvement in the power amplifier's phase distortion (AM/PM).

Abstract: Apparatus and methods for wideband envelope tracking systems are disclosed herein. In certain implementations, an envelope tracker includes a DC-to-DC converter, a current digital-to-analog converter (DAC), an error amplifier, a feedback circuit, and an AC combiner. The current DAC receives a digital envelope signal, and uses the digital envelope signal to generate an envelope current. The feedback circuit is connected between an output and an inverting input of the error amplifier, and the envelope current is provided to the error amplifier's inverting input. Additionally, the AC combiner generates a power amplifier supply voltage by combining an output of the DC-to-DC converter and an output of the error amplifier.

Abstract: This disclosure relates to a harmonic termination circuit that is separate from a load line. In one embodiment, the load line is configured to match an impedance at the power amplifier output at a fundamental frequency of the power amplifier output and the harmonic termination circuit is configured to terminate at a phase corresponding to a harmonic frequency of the power amplifier output. According to certain embodiments, the load line and the harmonic termination circuit can be electrically coupled to the power amplifier output external to a power amplifier die via different output pins of the power amplifier die.

Abstract: A variable load power amplifier that improves the performance of a power amplifier that provides both envelope tracking (ET) and average power tracking (APT). The variable load power amplifier can include a plurality of amplifiers that are each selectively connectable into one of a plurality of parallel combinations, each of the plurality of parallel combinations characterized by a corresponding load line. The variable load power amplifier can also include a plurality of control elements arranged to selectively connect one or more of the plurality of amplifiers into one of the plurality of parallel combinations, each of the plurality of control elements having a respective input terminal provided to receive a respective control signal, each of the plurality of control elements responsive to the respective control signal.

Abstract: Apparatus and methods for power amplifiers are disclosed. In one embodiment, a power amplifier circuit assembly includes a power amplifier and an impedance matching network. The impedance matching network is operatively associated with the power amplifier and is configured to provide a load line impedance to the power amplifier between about 6 ? and about 10 ?. The impedance matching network includes a fundamental matching circuit and one or more termination circuits, and the fundamental matching circuit and each of the of the one or more termination circuits include separate input terminals for coupling to an output of the power amplifier so as to allow the fundamental matching circuit and each of the one or more termination circuits to be separately tuned.

Abstract: Apparatus and methods for wideband envelope tracking systems are disclosed herein. In certain implementations, an envelope tracker includes a DC-to-DC converter, a current digital-to-analog converter (DAC), an error amplifier, a feedback circuit, and an AC combiner. The current DAC receives a digital envelope signal, and uses the digital envelope signal to generate an envelope current. The feedback circuit is connected between an output and an inverting input of the error amplifier, and the envelope current is provided to the error amplifier's inverting input. Additionally, the AC combiner generates a power amplifier supply voltage by combining an output of the DC-to-DC converter and an output of the error amplifier.