Abstract: Reconfigurable antenna systems with ground tuning pads are provided herein. In certain configurations, an antenna system includes an antenna element, a first tuning conductor spaced apart from the antenna element on a first side of the antenna element, a second tuning conductor spaced apart from the antenna element on a second side of the antenna element, a first ground tuning pad configured to receive a ground voltage, and a first switch electrically connected between the first tuning conductor and the first ground tuning pad. The first switch is operable to selectively connect the first tuning conductor to the first ground tuning pad to thereby tune the antenna element.

Abstract: Devices and methods related to stack assembly. In some embodiments, a radio-frequency (RF) module can include a packaging substrate configured to receive a plurality of components, and an electro-acoustic device mounted on the packaging substrate. The RF module can further include a die having an integrated circuit and mounted over the electro-acoustic device to form a stack assembly. The electro-acoustic device can be, for example, a filter device such as a surface acoustic wave filter. The die can be, for example an amplifier die such as a low-noise amplifier implemented on a silicon die.

Abstract: Stack assembly for radio-frequency applications. In some embodiments, a radio-frequency (RF) module can include a packaging substrate configured to receive a plurality of components, and an electro-acoustic device mounted on the packaging substrate. The RF module can further include a die having an integrated circuit and mounted over the electro-acoustic device to form a stack assembly. The electro-acoustic device can be, for example, a filter device such as a surface acoustic wave filter. The die can be, for example an amplifier die such as a low-noise amplifier implemented on a silicon die.

Abstract: Fast envelope tracking systems are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator and a differential error amplifier configured to operate in combination with one another to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The envelope tracking system further includes a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope of the RF signal. Additionally, the differential error amplifier generates an output current operable to adjust a voltage level of the power amplifier supply voltage based on comparing the single-ended envelope signal to a reference signal.

Abstract: An antenna structure can include a printed circuit board module and a mold compound disposed on a side of the printed circuit board module. A planar antenna is defined by a conformal shield layer disposed on a first surface of the mold compound such that the mold compound is disposed between the printed circuit board module and the conformal shield layer. The thickness of the mold compound layer and the shape of the conformal shield layer can be varied to optimize a performance of the antenna.

Abstract: Stack assembly for radio-frequency applications. In some embodiments, a radio-frequency (RF) module can include a packaging substrate configured to receive a plurality of components, and an electro-acoustic device mounted on the packaging substrate. The RF module can further include a die having an integrated circuit and mounted over the electro-acoustic device to form a stack assembly. The electro-acoustic device can be, for example, a filter device such as a surface acoustic wave filter. The die can be, for example an amplifier die such as a low-noise amplifier implemented on a silicon die.

Abstract: Fast envelope tracking systems are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator and a differential error amplifier configured to operate in combination with one another to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The envelope tracking system further includes a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope of the RF signal. Additionally, the differential error amplifier generates an output current operable to adjust a voltage level of the power amplifier supply voltage based on comparing the single-ended envelope signal to a reference signal.

Abstract: A method for manufacturing a package with a conformal shield antenna includes forming a mold compound layer, attaching the mold compound layer to a printed circuit board, applying a conformal shield layer on a first surface of the mold compound layer, the mold compound layer disposed between the conformal shield layer and the printed circuit board module, and shaping the conformal shield layer to define a planar antenna structure. Optionally, the method includes forming a cavity in the mold compound layer, applying a cover layer over the cavity to enclose the cavity and hardening the cover layer.

Abstract: Reconfigurable antenna systems with ground tuning pads are provided herein. In certain configurations, an antenna system includes an antenna element, a first tuning conductor spaced apart from the antenna element on a first side of the antenna element, a second tuning conductor spaced apart from the antenna element on a second side of the antenna element, a first ground tuning pad configured to receive a ground voltage, and a first switch electrically connected between the first tuning conductor and the first ground tuning pad. The first switch is operable to selectively connect the first tuning conductor to the first ground tuning pad to thereby tune the antenna element.

Abstract: Stack assembly having electro-acoustic device. In some embodiments, a radio-frequency (RF) module can include a packaging substrate configured to receive a plurality of components, and an electro-acoustic device mounted on the packaging substrate. The RF module can further include a die having an integrated circuit and mounted over the electro-acoustic device to form a stack assembly. The electro-acoustic device can be, for example, a filter device such as a surface acoustic wave filter. The die can be, for example an amplifier die such as a low-noise amplifier implemented on a silicon die.

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: High bandwidth envelope trackers are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator that operates in combination with a high bandwidth amplifier to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The high bandwidth amplifier includes an output that generates an output current for adjusting the power amplifier supply voltage, a first input that receives a reference signal, and a second input that receives an envelope signal indicating the envelope of the RF signal. The second input has lower input impedance than the first input to provide a rapid transient response and high envelope tracking bandwidth.

Abstract: Fast envelope tracking systems are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator and a differential error amplifier configured to operate in combination with one another to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The envelope tracking system further includes a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope of the RF signal. Additionally, the differential error amplifier generates an output current operable to adjust a voltage level of the power amplifier supply voltage based on comparing the single-ended envelope signal to a reference signal.

Abstract: Reconfigurable antenna systems with ground tuning pads are provided herein. In certain configurations, an antenna system includes a module substrate including a ground plane and a ground tuning pad configured to receive a ground voltage from the ground plane. The antenna system further includes an antenna element and a tuning conductor that is spaced apart from the antenna element and operable to load the antenna element. Furthermore, a switch is electrically connected between the tuning conductor and the ground tuning pad, and operates to selectively connect the tuning conductor to the ground plane by way of the ground tuning pad to provide tuning to the antenna element.

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: High bandwidth envelope trackers are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator that operates in combination with a high bandwidth amplifier to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The high bandwidth amplifier includes an output that generates an output current for adjusting the power amplifier supply voltage, a first input that receives a reference signal, and a second input that receives an envelope signal indicating the envelope of the RF signal. The second input has lower input impedance than the first input to provide a rapid transient response and high envelope tracking bandwidth.

Abstract: Fast envelope tracking systems are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator and a differential error amplifier configured to operate in combination with one another to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The envelope tracking system further includes a differential envelope amplifier configured to amplify a differential envelope signal to generate a single-ended envelope signal that changes in relation to the envelope of the RF signal. Additionally, the differential error amplifier generates an output current operable to adjust a voltage level of the power amplifier supply voltage based on comparing the single-ended envelope signal to a reference signal.

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: High bandwidth envelope trackers are provided herein. In certain embodiments, an envelope tracking system for a power amplifier includes a switching regulator that operates in combination with a high bandwidth amplifier to generate a power amplifier supply voltage for the power amplifier based on an envelope of a radio frequency (RF) signal amplified by the power amplifier. The high bandwidth amplifier includes an output that generates an output current for adjusting the power amplifier supply voltage, a first input that receives a reference signal, and a second input that receives an envelope signal indicating the envelope of the RF signal. The second input has lower input impedance than the first input to provide a rapid transient response and high envelope tracking bandwidth.

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.