In a radio frequency power amplifier, a semiconductor chip includes at least one first transistor amplifying a radio frequency signal, a first external-connection conductive member connected to the first transistor, a bias circuit including a second transistor that applies a bias voltage to the first transistor, and a second external-connection conductive member connected to the second transistor. The second external-connection conductive member at least partially overlaps with the second transistor when viewed in plan.

The embodiments described herein include amplifiers that are typically used in radio frequency (RF) applications. Specifically, the amplifiers described herein include one or more transient termination circuits coupled to transistor inputs. For example, the transient termination circuits can be configured to reduce the transient response for some signal energy at frequencies below a baseband frequency (f.sub.B) of signals being amplified while not similarly reducing the transient response for signal energy near a fundamental frequency (f.sub.0) of the signals being amplified.

The embodiments described herein include amplifiers that are typically used in radio frequency (RF) applications. Specifically, the amplifiers described herein include one or more transient termination circuits coupled to transistor inputs. For example, the transient termination circuits can be configured to reduce the transient response for some signal energy at frequencies below a baseband frequency (f.sub.B) of signals being amplified while not similarly reducing the transient response for signal energy near a fundamental frequency (f.sub.0) of the signals being amplified.

An envelope tracking (ET) integrated circuit (IC) (ETIC) is provided. The ETIC includes a number of ET circuits configured to generate a number of ET voltages based on a number of ET target voltages, respectively. In examples discussed herein, a selected ET circuit among the ET circuits is configured to generate a respective ET voltage based on a maximum ET target voltage among the ET target voltages. In this regard, the respective ET voltage generated by the selected ET circuit can be used as a reference ET voltage for the rest of the ET circuits in the ETIC. As a result, it may be possible to opportunistically turn off or reduce functionality of one or more other ET circuits in the ETIC, thus helping to reduce peak battery current and improve heat dissipation in an ET amplifier apparatus incorporating the ETIC.

An envelope tracking (ET) integrated circuit (IC) (ETIC) is provided. The ETIC includes a number of ET circuits configured to generate a number of ET voltages based on a number of ET target voltages, respectively. In examples discussed herein, a selected ET circuit among the ET circuits is configured to generate a respective ET voltage based on a maximum ET target voltage among the ET target voltages. In this regard, the respective ET voltage generated by the selected ET circuit can be used as a reference ET voltage for the rest of the ET circuits in the ETIC. As a result, it may be possible to opportunistically turn off or reduce functionality of one or more other ET circuits in the ETIC, thus helping to reduce peak battery current and improve heat dissipation in an ET amplifier apparatus incorporating the ETIC.

An advantageously fast and asynchronous interface is disclosed for the tuning of an RF frontend. The interface transmits a tuning word to the RF frontend that controls a tuning of the RF frontend responsive to a channel index.

An advantageously fast and asynchronous interface is disclosed for the tuning of an RF frontend. The interface transmits a tuning word to the RF frontend that controls a tuning of the RF frontend responsive to a channel index.

A Doherty amplifier according to the present disclosure includes an input terminal, an output terminal, a carrier amplifier connected between the input terminal and the output terminal, a peak amplifier connected in parallel to the carrier amplifier between the input terminal and the output terminal, a first input matching circuit connected between the input terminal and the carrier amplifier and a second input matching circuit connected between the input terminal and the peak amplifier, wherein the carrier amplifier and the peak amplifier output signals toward outside in directions opposite to each other.

A Doherty amplifier according to the present disclosure includes an input terminal, an output terminal, a carrier amplifier connected between the input terminal and the output terminal, a peak amplifier connected in parallel to the carrier amplifier between the input terminal and the output terminal, a first input matching circuit connected between the input terminal and the carrier amplifier and a second input matching circuit connected between the input terminal and the peak amplifier, wherein the carrier amplifier and the peak amplifier output signals toward outside in directions opposite to each other.

Methods and apparatus for providing amplifier protection for a radio frequency (RF) front-end circuit. An example RF front-end circuit generally includes an amplifier with a gain, a first sensor configured to sense a first power (or voltage) of a first node coupled to an input of the amplifier, a second sensor configured to sense a second power (or voltage) of a second node coupled to an output of the amplifier, and logic coupled to the first and second sensors. The logic is generally configured to determine that the second power (or voltage) is outside a range based on the gain and the first power (or voltage) and to take an action to protect the amplifier based on the determination. By utilizing the techniques and apparatus described herein, protection can be provided to the amplifier(s) in an RF front-end circuit without significantly impacting the performance of the RF front-end circuit.