A multi-mode envelope tracking (ET) amplifier circuit is provided. The multi-mode ET amplifier circuit can operate in a low-resource block (RB) mode, a mid-RB mode, and a high-RB mode. The multi-mode ET amplifier circuit includes fast switcher circuitry having a first switcher path and a second switcher path and configured to generate an alternating current (AC) current. A control circuit activates the fast switcher circuitry in the mid-RB mode and the high-RB mode, while deactivating the fast switcher circuitry in the low-RB mode. More specifically, the control circuit selectively activates one of the first switcher path and the second switcher path in the mid-RB mode and activates both the first switcher path and the second switcher path in the high-RB mode. As a result, it is possible to improve efficiency of ET tracker circuitry and the multi-mode ET amplifier circuit in all operation modes.

A matching network is a matching network of a power amplifier circuit that outputs a signal obtained by a differential amplifier amplifying power of a high-frequency signal. The matching network includes an input-side winding connected between differential outputs of the differential amplifier; an output-side winding that is coupled to the input-side winding via an electromagnetic field and whose one end is connected to a reference potential; a first LC series resonant circuit including a capacitive element and an inductive element connected in series with each other, and being connected in parallel with the input-side winding; and a second LC series resonant circuit including a capacitive element and an inductive element connected in series with each other, and being connected in parallel with the output-side winding.

An envelope tracking (ET) amplifier apparatus is provided. The ET amplifier apparatus includes an amplifier circuit configured to amplify a radio frequency (RF) signal based on a modulated voltage. In examples discussed herein, the amplifier circuit is co-located with a local voltage amplifier circuit configured to supply the modulated voltage such that a trace inductance between the amplifier circuit and the local voltage amplifier circuit can be reduced to below a defined threshold. By co-locating the amplifier circuit with the local voltage amplifier circuit to reduce a coupling distance between the amplifier circuit and the local voltage amplifier circuit and thus the trace inductance associated with the coupling distance, it may be possible to reduce degradation in the modulated voltage. As a result, it may be possible to improve efficiency and maintain linearity in the amplifier circuit, particularly when the RF signal is modulated at a higher modulation bandwidth.

Systems and methods for amplifying an input signal include amplifier circuitry, an itail connection coupled between a positive voltage circuitry and the negative voltage circuitry and operable to generate an itail voltage corresponding to a greater of the positive voltage input signal (Vp) and the negative voltage input signal (Vn), a first resistor rgp disposed to receive the itail voltage and a first voltage corresponding to Vp, and a second resistor rgn disposed to receive the itail voltage and a second voltage corresponding to Vn. A first current output node is coupled to the output of rgp and operable to output a positive output current (Ioutp) corresponding to the current flowing through rgp, and a second current output is coupled to the output of rgn and operable to output a negative output current (Ioutn) corresponding to the current flowing through rgn.

Techniques are disclosed implementing a tunable transformer with additional taps in at least one of the three coils. The tunable transformer enables the resonant frequency within RF transceiver matching networks to be adjusted without substantially impacting the output power at resonance. The tunability of the transformer is partially driven by the insertion of additional coils within the transformer, which are selectively switched and may be further coupled with a tunable capacitance. The tunability of the transformer is further driven via the use of at least one multi-tap transformer coil, which allows electronic components to be coupled to different coil taps to thereby facilitate an adjustable DC inductance. Doing so counteracts changes in mutual inductance between the non-switched coils, and facilitates the stabilization of output power with shifts in resonant frequency.

Systems, methods, and circuitries are provided for generating supply voltages for a power amplifier in a digital envelope tracking system. In one example, a voltage generation circuitry converts a source voltage into a supply voltage based on a target voltage. The voltage regulation circuitry includes an adjustable boost circuitry that multiplies the source voltage to generate an input voltage having a voltage equal to or greater than the source voltage and a step-down regulator circuitry that regulates the input voltage to generate a regulated output voltage having a voltage that is less than or equal to the input voltage. A voltage splitter circuitry is coupled to the regulated output voltage and is configured to generate at least one derived output voltage from the regulated output voltage. A supply modulator provides a selected one of the at least one derived output voltage to a power amplifier.

A power amplifier includes a semiconductor die having a main amplifier and a peaking amplifier. The main amplifier includes at least one first transistor, and the peaking amplifier includes at least one second transistor that is different than the first transistor. The peaking amplifier is configured to modulate a load impedance of the main amplifier responsive to a common gate bias applied to respective gates of the first and second transistors. Related fabrication and methods of operation are also discussed.

A Doherty power amplifier having a main power amplification device and an auxiliary power amplification device arranged in parallel with the main power amplification device includes a load modulation circuit having a harmonic injection circuit connected with respective outputs of the main power amplification device and the auxiliary power amplification device. The harmonic injection circuit is arranged to provide a phase shift to simultaneously modulate transfer of second harmonic components generated at the main power amplification device to the auxiliary power amplification device and transfer of second harmonic components generated at the auxiliary power amplification device to the main power amplification device, when the main power amplification device and the auxiliary power amplification device are operated at saturation.

A power amplifier circuit includes a first transistor, a capacitor, and a second transistor. The first transistor has an emitter electrically connected to a reference potential, a base, and a collector electrically connected to a first power supply potential. A first end of the capacitor is electrically connected to the collector of the first transistor. The second transistor has an emitter electrically connected to a second end of the capacitor and electrically connected to the reference potential, a base, and a collector electrically connected to the first power supply potential. An RF output signal obtained by amplifying the RF input signal is output from the collector of the second transistor. A second bias circuit includes a third transistor having a collector electrically connected to a second power supply potential, a base, and an emitter from which the second bias current or voltage is output.

A transmitter and a method capable of transmitting a transmission signal that satisfies a high S/N ratio are provided. A transmitter includes a first signal generation unit including a distributor configured to receive a first N (N: an integer greater than or equal to 3) value digital signal generated from a baseband signal, divide the first N-value digital signal into (N1) binary digital signals, and output the divided (N1) binary digital signals, and a signal amplification unit configured to amplify each of the (N1) binary digital signals and output a transmission signal obtained by combining the amplified (N1) signals.