An envelope tracking (ET) amplifier apparatus is provided. The ET amplifier apparatus includes an ET integrated circuit (IC) (ETIC) and a distributed ETIC (DETIC) coupled to the ETIC. The DETIC may be configured to provide a distributed voltage to a distributed amplifier circuit for amplifying a distributed radio frequency (RF) signal. In examples discussed herein, the ETIC is configured to generate a low-frequency current, which can affect the distributed voltage, at a desired level based on a feedback signal received from the DETIC. The DETIC may be configured to generate the feedback signal based on an indication(s) related to the distributed voltage. By dynamically adjusting the low-frequency current, and thus the distributed voltage, based on the feedback signal, it may be possible to maintain operating efficiency of the distributed amplifier circuit across a wider range of modulation bandwidth with minimal cost and/or size impact on the ET amplifier apparatus.

An envelope tracking (ET) amplifier apparatus is provided. The ET amplifier apparatus includes an ET integrated circuit (IC) (ETIC) and a distributed ETIC (DETIC) coupled to the ETIC. The DETIC may be configured to provide a distributed voltage to a distributed amplifier circuit for amplifying a distributed radio frequency (RF) signal. In examples discussed herein, the ETIC is configured to generate a low-frequency current, which can affect the distributed voltage, at a desired level based on a feedback signal received from the DETIC. The DETIC may be configured to generate the feedback signal based on an indication(s) related to the distributed voltage. By dynamically adjusting the low-frequency current, and thus the distributed voltage, based on the feedback signal, it may be possible to maintain operating efficiency of the distributed amplifier circuit across a wider range of modulation bandwidth with minimal cost and/or size impact on the ET amplifier apparatus.

Components of a power amplifier controller may support lower voltages than the power amplifier itself. As a result, a surge protection circuit that prevents a power amplifier from being damaged due to a power surge may not effectively protect the power amplifier controller. Embodiments disclosed herein present an overvoltage protection circuit that prevents a charge-pump from providing a voltage to a power amplifier controller during a detected surge event. By separately detecting and preventing a voltage from being provided to the power amplifier controller during a surge event, the power amplifier controller can be protected regardless of whether the surge event results in a voltage that may damage the power amplifier. Further, embodiments of the overvoltage protection circuit can prevent a surge voltage from being provided to a power amplifier operating in 2G mode.

Components of a power amplifier controller may support lower voltages than the power amplifier itself. As a result, a surge protection circuit that prevents a power amplifier from being damaged due to a power surge may not effectively protect the power amplifier controller. Embodiments disclosed herein present an overvoltage protection circuit that prevents a charge-pump from providing a voltage to a power amplifier controller during a detected surge event. By separately detecting and preventing a voltage from being provided to the power amplifier controller during a surge event, the power amplifier controller can be protected regardless of whether the surge event results in a voltage that may damage the power amplifier. Further, embodiments of the overvoltage protection circuit can prevent a surge voltage from being provided to a power amplifier operating in 2G mode.

A temperature compensation circuit comprises a temperature coefficient circuit that generates a temperature coefficient that is temperature dependent and a compensation circuit that generates a compensation signal based on an indication of temperature of an amplifier and the temperature coefficient, and based on the compensation signal, a gain of the amplifier is adjusted to improve amplifier linearity during data bursts.

A temperature compensation circuit comprises a temperature coefficient circuit that generates a temperature coefficient that is temperature dependent and a compensation circuit that generates a compensation signal based on an indication of temperature of an amplifier and the temperature coefficient, and based on the compensation signal, a gain of the amplifier is adjusted to improve amplifier linearity during data bursts.

A semiconductor integrated circuit comprises a semiconductor substrate having a via-hole, a front-side-metal layer formed on a top surface of the semiconductor substrate, a seed-metal layer and a backside-metal layer. A bottom surface of an inner surface of the via-hole is at least partially defined by the front-side-metal layer. A surrounding surface of the inner surface of the via-hole is at least partially defined by the semiconductor substrate. The seed-metal layer is formed on the inner surface of the via-hole and a bottom surface of the semiconductor substrate such that the seed-metal layer and the front-side-metal layer are connected. The backside-metal layer is formed on an outer surface of the seed-metal layer. An aspect ratio of the via-hole is greater than or equal to 0.2 and less than or equal to 3, thereby a thickness uniformity of the backside-metal layer is improved.

Provided is a generator that includes a housing, a high-power circuit including a power amplifier, and a low-power circuit. An air flow guidance plate divides the housing into at least two compartments including a high-power compartment and a low-power compartment. The high-power circuit is disposed within the high-power compartment and the low-power circuit is disposed within the low-power compartment.

Provided is a generator that includes a housing, a high-power circuit including a power amplifier, and a low-power circuit. An air flow guidance plate divides the housing into at least two compartments including a high-power compartment and a low-power compartment. The high-power circuit is disposed within the high-power compartment and the low-power circuit is disposed within the low-power compartment.

In a transistor formed on a semiconductor die mounted on a substrate, where the transistor output is connected to a circuit on the substrate, a bond pad electrically connected to a transistor drain finger manifold extends less than the full length of the manifold. By controlling the length of the bond pad, the parasitic capacitance it contributes may be controlled. In applications such as a Doherty amplifier, this parasitic capacitance forms part of the quarter-wave transmission line of an impedance inverter, and hence directly impacts amplifier performance. In particular, by reducing the parasitic capacitance contribution from transistor output bond pads, the bandwidth of a Doherty amplifier circuit may be improved. At GHz frequencies and with state of the art transistor device feature sizes, concerns about phase mismatch between drain finger outputs are largely moot.