A low frequency loss correction circuit that improves the efficiency of a power amplifier at near-DC low frequencies The low frequency loss correction circuit can include a signal error detection circuit configured to produce an error signal in response to detecting one or more frequency components of a tracking signal below a cutoff frequency that are substantially attenuated through a capacitive path. The low frequency loss correction circuit can include a drive circuit configured to convert the error signal into a low frequency correction signal, and provide the low frequency correction signal to a voltage supply line, the low frequency correction signal including at least some of the one or more frequency components of the tracking signal below a cutoff frequency that are substantially attenuated through the capacitive path.

Disclosed herein are power amplification systems that are dynamically biased based on a signal indicative of an envelope of the signal being amplified. The power amplification systems include a power amplifier configured to amplify an input radio-frequency (RF) signal to generate an output RF signal when biased by a biasing signal. The power amplification systems also include a bias component configured to generate the biasing signal based on an envelope signal indicative of an envelope of the input RF signal. The biasing signal can improve or enhance the linearity of the power amplification systems.

A transmission module includes n oscillator modules and a phase command signal generator. Each of the oscillator modules includes a voltage controlled oscillator and an amplification circuit. The voltage controlled oscillators output transmission high-frequency signals having the same frequency and synchronized among the n oscillator modules by synchronous control based on a common reference signal. The amplification circuits each perform power amplification for the transmission high-frequency signal from a corresponding one of the voltage controlled oscillators and output the resultant signal. Phases of the transmission high-frequency signals synchronized among the n oscillator modules and output from the voltage controlled oscillators are separately controlled according to respective n phase command signals from the phase command signal generator.

An envelope tracking power management circuit is disclosed. An envelope tracking power management circuit includes a first envelope tracking amplifier(s) and a second envelope tracking amplifier(s), each configured to amplify a respective radio frequency (RF) signal(s) based on a respective supply voltage. A power management circuit can determine that a selected envelope tracking amplifier, which can be either the first envelope tracking amplifier(s) or the second envelope tracking amplifier(s), receives the respective supply voltage lower than a voltage required to amplify the respective RF signal(s) to a predetermined voltage. In response, the power management circuit provides a boosted voltage, which is no less than the required voltage, to the selected envelope tracking amplifier. As such, it is possible to enable the selected envelope tracking amplifier to amplify the respective RF signal(s) to the predetermined voltage without increasing cost, footprint, and power consumption of the envelope tracking power management circuit.

In some embodiments, a power amplification system can comprise a current source, an input switch configured to alternatively feed current from the current source to a high-power circuit path and a low-power circuit path, and a band switch including a switch arm for switching between a plurality of bands. Each of the high-power circuit path and the low-power circuit path can be connected to the switch arm.

Disclosed is a radio frequency unit, including a power amplification module, a filtering module and a signal connector; where one end of the signal connector is connected to the filtering module, and the other end is connected to the power amplification module; the power amplification module is provided with a power amplification connector; a guide structure for guiding the power amplification connector to be coaxially aligned with the signal connector is formed on one end of the signal connector connected with the power amplification module; and through the guide structure, the power amplification connector is coaxially connected with the signal connector.

A variable-gain power amplifying technique includes generating, with a network of one or more reactive components included in an oscillator, a first oscillating signal, and outputting, via one or more taps included in the network of the reactive components, a second oscillating signal. The second oscillating signal has a magnitude that is proportional to and less than the first oscillating signal. The power amplifying technique further includes selecting one of the first and second oscillating signals to use for generating a power-amplified output signal, and amplifying the selected one of the first and second oscillating signals to generate the power-amplified output signal.

An amplification circuit includes a first switching circuit that includes input terminals and first and second output terminals and that puts the second output terminal into an open state with respect to the input terminals while selectively putting the first output terminal into a state of being connected to any of the input terminals or selectively puts the second output terminal into a state of being connected to any of input terminals while putting the first output terminal into a state of being open with respect to the input terminals; a matching network that is connected to the first output terminal; an amplifier that is connected to an output side of the matching network; a second switching circuit that is connected to an output side of the amplifier; and a bypass path that electrically connects the second output terminal and an output terminal of the second switching circuit. The amplifier is a variable-gain amplifier.

An envelope tracking (ET) amplifier apparatus is provided. The ET amplifier apparatus includes an ET integrated circuit (ETIC) and a distributed ETIC (DETIC) coupled to a single-wire bus that correspond to a first bus access priority and a second bus access priority, respectively. The ETIC and the DETIC can contend for access to the single-wire bus by asserting a bus contention indication(s) when the single-wire bus is in a defined bus state configured to permit bus contention. In a non-limiting example, a winner for the single-wire bus is a peer device having a highest bus access priority between the ETIC and the DETIC. In this regard, each of the ETIC and the DETIC can have a chance to initiate communications over the single-wire bus, thus making it possible for the single-wire bus to function based on bidirectional peer-to-peer (P2P) bus architecture capable of supporting more application and/or deployment scenarios.

A user equipment (UE) includes a transmit chain that includes multiple radio frequency transmitters, multiple power amplifiers and a front end (FE) through which signals are transmitted. To achieve a high power UE solution, aspects of the disclosure selectively combine two or more power amplifier outputs based on an expected power output of the UE. To synchronously combine the outputs, an output feedback signal from a feedback receiver is used to adjust a delay and a phase of one or more signals associated with the power amplifiers.