Apparatus and methods for quadrature combined Doherty amplifiers are provided herein. In certain embodiments, a separator is used to separate a radio frequency (RF) input signal into a plurality of input signal components that are amplified by a pair of Doherty amplifiers operating in quadrature. Additionally, a combiner is used to combine a plurality of output signal components generated by the pair of Doherty amplifiers, thereby generating an RF output signal exhibiting quadrature balancing.

A first sub-collector layer functions as an inflow path of a collector current that flows in a collector layer of a heterojunction bipolar transistor. A collector ballast resistor layer having a lower doping concentration than the first sub-collector layer is disposed between the collector layer and the first sub-collector layer.

A receiver circuit is disclosed. The receiver circuit includes an amplifier configured to generate an RF signal based on a received signal, where the RF signal includes an information signal and a blocker signal modulating an RF carrier frequency. The receiver circuit also includes an RF filter connected to the amplifier, where the RF filter is configured to selectively attenuate the blocker signal.

Various embodiments relate to a packaged radio frequency (RF) amplifier device implementing a split bondwire where the direct ground connection of an output capacitor is replaced with a set of bondwires connecting to ground in a direction opposite to the wires connecting to the output of a transistor to an output pad. This is done in order to reduce the effects of mutual inductance between the various bondwires associated with the output of the RF amplifier device.

An example process includes reducing a quality factor of a first tunable bandpass filter, used, for example, in a low-noise amplifier stage of a polar receiver. A first wideband test signal centered at a desired center frequency of a second tunable bandpass filter is received. A frequency response of the second tunable bandpass filter to the first wideband test signal is estimated using a Fast Fourier Transform (FFT) signal processor. At least a resonant frequency or a quality factor of the second tunable bandpass filter are calibrated based at least in part on a portion of the estimated frequency response of the second tunable bandpass filter obtained from the FFT signal processor. Frequency response characteristics of the first tunable bandpass filter may be similarly tuned in accordance with the example process.

An envelope tracking (ET) amplifier apparatus is provided. In examples discussed herein, the ET amplifier apparatus can be configured to operate in a fifth-generation (5G) standalone (SA) mode and a 5G non-standalone (NSA) mode. In the SA mode, the ET amplifier apparatus can enable a first pair of amplifier circuits to amplifier a 5G signal for concurrent transmission in a 5G band(s). In the NSA mode, the ET amplifier apparatus can enable a second pair of amplifier circuits to amplify a non-5G anchor signal and a 5G signal for concurrent transmission in a non-5G anchor band(s) and a 5G band(s), respectively. As such, the ET circuit may be provided in a communication apparatus (e.g., a 5G-enabled smartphone) to help improve power amplifier linearity and efficiency in both 5G SA and NSA modes.

A wireless transmission circuit includes a first induction circuit, a second induction circuit, a detection circuit, a first signal adjustment circuit, and a third induction circuit. The first induction circuit is configured to receive a first signal outputted from a power amplifier. The second induction circuit is configured to output the received first signal as a second signal. The detection circuit is configured to detect a common mode signal associated with the first signal. The first signal adjustment circuit is configured to adjust a phase or an amplitude of the common mode signal to generate a third signal. The third induction circuit is configured to receive the third signal and be coupled to the second induction circuit to reduce a second harmonic in the second signal.

Embodiments are described herein for power generation systems and methods that use quadrature splitters and combiners to facilitate plasma stability and control. For one embodiment, a quadrature splitter receives an input signal and generates a first and second signals as outputs with the second signal being ninety degrees out of phase with respect to the first signal. Two amplifiers then generate a first and second amplified signals. A quadrature combiner receives the first and second amplified signals and generates a combined amplified signal that represents re-aligned versions of the first and second amplified signals. The power amplifiers can be combined into a system to generate a high power output to a processing chamber. Further, detectors can generate measurements used to monitor and control power generation. The power amplifiers, system, and methods provide significant advantages for high-power generation delivered to process chambers for plasma generation during plasma processing.

An amplifier comprises a common emitter stage coupled to a first and a second input, a common base stage coupled to the common emitter stage and to a first and a second output, and a cancellation path coupled to the common emitter stage and the common base stage and to the first and second outputs. The cancellation path generates a first cancellation signal that is 180 degrees out of phase with a first leakage signal at the first output and a second cancellation signal that is 180 degrees out of phase with a second leakage signal at the second output. The cancellation path comprises a first cancellation transistor coupled to the common emitter stage and the common base stage and to the first output and a second cancellation transistor coupled to the common emitter stage and the common base stage and to the second output.

A power amplifier apparatus is provided. The power amplifier apparatus includes a number of multi-stage power amplifiers and a bias circuit configured to generate a number of bias signals (e.g., bias current or bias voltage) to control (e.g., activate or deactivate) the multi-stage power amplifiers. In examples disclosed herein, only one of the multi-stage power amplifiers is activated at a given time. In this regard, the bias circuit can generate the bias signals to collectively activate one of the multi-stage power amplifiers, while deactivating the rest of the multi-stage power amplifiers. As such, it may be possible to control a larger number of power amplifier stages based on a smaller number of bias signals. As a result, it may be possible to eliminate a biasing bump pad(s) from the power amplifier apparatus, thus helping to reduce the footprint and cost of the power amplifier apparatus.