A distributed active transformer includes an input transformer set and an output transformer set. Active stages are coupled between a transformer in the input transformer set and a transformer in the output transformer set. The input and output transformer sets are each configured as a slab transformer. The input slab transformer includes a single primary slab and many secondary slabs. The output slab transformer includes many primary slabs and a single secondary slab.

A distributed active transformer includes an input transformer set and an output transformer set. Active stages are coupled between a transformer in the input transformer set and a transformer in the output transformer set. The input and output transformer sets are each configured as a slab transformer. The input slab transformer includes a single primary slab and many secondary slabs. The output slab transformer includes many primary slabs and a single secondary slab.

The present invention discloses a programmable gain amplifier having mode-switching mechanism. An operational amplifier includes a first input terminal, a second input terminal and an output terminal. The second input terminal is coupled to a ground terminal. The output terminal generates an output signal. A variable resistor and a first switch are coupled in series between a first terminal and a second terminal that coupled to the first input terminal. A first variable capacitor and a second switch are coupled in series between the first terminal and the second terminal. A second variable capacitor and a third switch are coupled in series between the first terminal and the ground terminal. A low-pass resistor and a low-pass capacitor are coupled in parallel between the first input terminal and the output terminal. An input resistor is coupled between a signal input terminal and the first terminal to receive an input signal from the signal input terminal. The first, the second and the third switches receive a set of mode-switching signals to switch to form a path or an open-circuit.

Various examples are directed to systems and methods for digital predistortion (DPD). A linear digital predistortion (DPD) circuit may be programmed to generate a pre-distorted signal linear component based at least in part on a complex baseband signal. A nonlinear DPD circuit may be programmed to generate a pre-distorted signal nonlinear component based at least in part on the complex baseband signal. A mixer circuit programmed to generate a pre-distorted signal based at least in part on the pre-distorted signal linear component and the pre-distorted signal nonlinear component.

An exemplary structure has an output stage; a driver stage; and a power stage connected between the driver stage and the output stage. The power stage includes a first transistor and a second transistor connected in series between the driver stage and the output stage. The power stage also includes a third transistor and a fourth transistor connected in series between the driver stage and the output stage. An inductor has a first terminal electrically connected to a first node between the first transistor and the second transistor and a second terminal electrically connected to a second node between the third transistor and the fourth transistor. The inductor is configured to provide impedance matching between common-gate stages of the power stage.

A power amplifier module includes an amplifier that amplifies an input signal and outputs an amplified signal, a matching circuit disposed between an output terminal of the amplifier and a subsequent circuit, a choke inductor having a first end to which a power supply voltage is applied and a second end from which power supply is provided to the amplifier through the output terminal of the amplifier, and a first attenuation circuit disposed between the output terminal of the amplifier and the second end of the choke inductor and configured to attenuate a harmonic component of the amplified signal.

A power amplifier module includes an amplifier that amplifies an input signal and outputs an amplified signal, a matching circuit disposed between an output terminal of the amplifier and a subsequent circuit, a choke inductor having a first end to which a power supply voltage is applied and a second end from which power supply is provided to the amplifier through the output terminal of the amplifier, and a first attenuation circuit disposed between the output terminal of the amplifier and the second end of the choke inductor and configured to attenuate a harmonic component of the amplified signal.

An electronic device includes a waveform generator, a comparator, and an amplifier. The waveform generator receives a voltage from a power supply to the electronic device and outputs a voltage waveform signal. The comparator compares an input signal and the voltage waveform signal to output a first pulse-width-modulated signal. The amplifier receives the first pulse-width-modulated signal and outputs a second pulse-width-modulated signal.

An electronic device includes a waveform generator, a comparator, and an amplifier. The waveform generator receives a voltage from a power supply to the electronic device and outputs a voltage waveform signal. The comparator compares an input signal and the voltage waveform signal to output a first pulse-width-modulated signal. The amplifier receives the first pulse-width-modulated signal and outputs a second pulse-width-modulated signal.

A transistor amplifier includes a group III-nitride based amplifier die including a gate terminal, a drain terminal, and a source terminal on a first surface of the amplifier die and an interconnect structure electrically bonded to the gate terminal, drain terminal and source terminal of the amplifier die on the first surface of the amplifier die and electrically bonded to an input path and output path of the transistor amplifier.