A low noise amplifier may include a post distortion cancellation block coupled to the low noise amplifier. The post distortion cancellation block may include a diode, and phase-shift logic. The phase-shift logic may be coupled in series with the diode.

Systems for providing isolation of a bias signal relative to a radio frequency (RF) signal in an integrated circuit, and related circuits, modules, and methods, are disclosed herein. In one example embodiment, a system includes an inductor, a bypass capacitor, and a transmission line segment, which includes first and second ends and extends between the first and second ends. The first end is at least indirectly coupled to the bypass capacitor, the second end is at least indirectly coupled to a first additional end of the inductor, and a second additional end of the inductor is configured to be coupled at least indirectly to a device through which the RF signal is being communicated. The transmission line segment is configured to impart a non-negligible phase shift to a signal communicated between the first and second ends, or is configured to have a non-negligible effective inductance.

Systems for providing isolation of a bias signal relative to a radio frequency (RF) signal in an integrated circuit, and related circuits, modules, and methods, are disclosed herein. In one example embodiment, a system includes an inductor, a bypass capacitor, and a transmission line segment, which includes first and second ends and extends between the first and second ends. The first end is at least indirectly coupled to the bypass capacitor, the second end is at least indirectly coupled to a first additional end of the inductor, and a second additional end of the inductor is configured to be coupled at least indirectly to a device through which the RF signal is being communicated. The transmission line segment is configured to impart a non-negligible phase shift to a signal communicated between the first and second ends, or is configured to have a non-negligible effective inductance.

Disclosed herein are signal amplifiers having a plurality of amplifier cores. Individual amplifier cores can be designed for particular gain modes to enhance particular advantages while reducing other disadvantages. The signal amplifier can then switch between amplifier cores when switching gain modes to achieve desired performance characteristics (e.g., improving noise figure or linearity). Examples of signal amplifiers disclosed herein include amplifier architectures with a high gain amplifier core that reduces the noise figure and a linearity boost amplifier core that increases linearity (e.g., for lower gain modes). The disclosed signal amplifiers have a first active core with amplification chains for each of a plurality of inputs and a second active core with a single amplification chain to amplify signals received at the plurality of inputs.

Disclosed herein are signal amplifiers having a plurality of amplifier cores. Individual amplifier cores can be designed for particular gain modes to enhance particular advantages while reducing other disadvantages. The signal amplifier can then switch between amplifier cores when switching gain modes to achieve desired performance characteristics (e.g., improving noise figure or linearity). Examples of signal amplifiers disclosed herein include amplifier architectures with a high gain amplifier core that reduces the noise figure and a linearity boost amplifier core that increases linearity (e.g., for lower gain modes). The disclosed signal amplifiers have a first active core with amplification chains for each of a plurality of inputs and a second active core with a single amplification chain to amplify signals received at the plurality of inputs.

An apparatus is disclosed for current-mode filtering using current steering. In an example aspect, the apparatus includes a filter. The filter includes a current-steering node, a first output node, a second output node, a wideband path, and a narrowband path. The wideband path is coupled between the current-steering node and the first output node. The wideband path includes a wideband low-pass filter configured to pass frequencies within a wide passband. The narrowband path is coupled between the current-steering node and the second output node. The narrowband path includes a narrowband low-pass filter configured to pass a portion of the frequencies that are within a narrow passband.

The present disclosure relates to a power amplifier (PA) system provided in a semiconductor device and having feed forward gain control. The PA system comprises a transmit path and control circuitry. The transmit path is configured to amplify an input radio frequency (RF) signal and comprises a first tank circuit and a PA stage. The control circuitry is configured to detect a power level associated with the input RF signal and control a first bias signal provided to the PA stage based on a first function of the power level and control a quality factor (Q) of the first tank circuit based on a second function of the power level.

The present disclosure relates to a power amplifier (PA) system provided in a semiconductor device and having feed forward gain control. The PA system comprises a transmit path and control circuitry. The transmit path is configured to amplify an input radio frequency (RF) signal and comprises a first tank circuit and a PA stage. The control circuitry is configured to detect a power level associated with the input RF signal and control a first bias signal provided to the PA stage based on a first function of the power level and control a quality factor (Q) of the first tank circuit based on a second function of the power level.

A transceiver circuit and related radio frequency (RF) circuit are provided. An RF circuit is coupled to a transceiver circuit configured to generate an envelope tracking (ET) target voltage. The RF circuit includes a tracker circuit and a power amplifier circuit(s). The tracker circuit may have inherent frequency-dependent impedance that can interact with a load current of the amplifier circuit(s) to cause degradation in an ET modulated voltage, which can lead to spectral distortions in an RF offset spectrum. As such, a voltage compensation circuit is provided in the transceiver circuit and configured to add a voltage compensation term in the ET target voltage. By adding the voltage compensation term into the ET target voltage, it is possible to compensate for the degradation in the ET modulated voltage, thus helping to reduce the spectral distortions in the RF offset spectrum and improve linearity and efficiency of the amplifier circuit(s).

A transceiver circuit and related radio frequency (RF) circuit are provided. An RF circuit is coupled to a transceiver circuit configured to generate an envelope tracking (ET) target voltage. The RF circuit includes a tracker circuit and a power amplifier circuit(s). The tracker circuit may have inherent frequency-dependent impedance that can interact with a load current of the amplifier circuit(s) to cause degradation in an ET modulated voltage, which can lead to spectral distortions in an RF offset spectrum. As such, a voltage compensation circuit is provided in the transceiver circuit and configured to add a voltage compensation term in the ET target voltage. By adding the voltage compensation term into the ET target voltage, it is possible to compensate for the degradation in the ET modulated voltage, thus helping to reduce the spectral distortions in the RF offset spectrum and improve linearity and efficiency of the amplifier circuit(s).