Abstract: A radio-frequency impedance tuner can include first and second nodes, a bypass path, first and second series capacitance paths, and an inductance path, with each path being implemented between the first and second nodes and including a switch configured to allow the path to couple or uncouple the first and second nodes. The tuner can further include first and second shunt paths, with each shunt path being implemented between the second node and ground and including a switch configured to allow the shunt path to couple or uncouple the second node and the ground. The tuner can further include a switchable grounding path implemented along the inductance path and configured to allow the inductance path to function as a series inductance path between the first and second nodes, or as a shunt inductance path between the ground and a node along the inductance path.

Abstract: Apparatus and methods for beamforming communication systems with power control based on antenna pattern configuration are provided. In certain embodiments, a beamforming communication system includes an antenna array including a plurality of antenna elements. The beamforming communication system further includes a plurality of signal conditioning circuits operatively associated with the antenna elements, and an antenna array management circuit that generates a plurality of control signals that individually control the signal conditioning circuits. The antenna array management circuit achieves a desired level of power control based on generating the control signals to select an antenna pattern configuration associated with a desired power control level.

Abstract: Integrated Doherty power amplifiers are provided herein. In certain implementations, a Doherty power amplifier includes a carrier amplification stage that generates a carrier signal, a peaking amplification stage that generates a peaking signal, and an antenna structure that combines the carrier signal and the peaking signal. The antenna structure radiates a transmit wave in which the carrier signal and the peaking signal are combined with a phase shift.

Abstract: Apparatus and methods for beamforming communication systems with power control based on antenna pattern configuration are provided. In certain embodiments, a beamforming communication system includes an antenna array including a plurality of antenna elements. The beamforming communication system further includes a plurality of signal conditioning circuits operatively associated with the antenna elements, and an antenna array management circuit that generates a plurality of control signals that individually control the signal conditioning circuits. The antenna array management circuit achieves a desired level of power control based on generating the control signals to select an antenna pattern configuration associated with a desired power control level.

Abstract: A capless impedance tuner can include first node and second nodes, a first series path, a second series path, and an inductance path, each between the first node and the second node and including a switch to allow the path to couple or uncouple the first and second nodes. Each series path can be configured to allow a substantially continuous flow of a direct current between the first node and the second node when coupled. The tuner can further include a shunt path with a switch to allow coupling or uncoupling of the second node and ground. The tuner can further include a switchable grounding path implemented along the inductance path and configured to allow the inductance path to function as a series inductance path between the first and second nodes, or as a shunt inductance path between the ground and a node along the inductance path.

Abstract: Phase control for carrier aggregation. In some embodiments, a carrier aggregation circuit can include a first filter configured to allow operation in a first frequency band, and a second filter configured to allow operation in a second frequency band. The circuit can further include a first path implemented between the first filter and a common node, with the first path being configured to provide a substantially matched impedance for the first frequency band and a substantially open-circuit impedance for the second frequency band. The circuit can further include a second path implemented between the second filter and the common node, with the second path being configured to provide a substantially matched impedance for the second frequency band and a substantially open-circuit impedance for the first frequency band.

Abstract: An antenna impedance tuner can include first and second nodes, a bypass path, first and second series capacitance paths, and an inductance path, with each path being implemented between the first and second nodes and including a switch configured to allow the path to couple or uncouple the first and second nodes. The tuner can further include first and second shunt paths, with each shunt path being implemented between the second node and ground and including a switch configured to allow the shunt path to couple or uncouple the second node and the ground. The tuner can further include a switchable grounding path implemented along the inductance path and configured to allow the inductance path to function as a series inductance path between the first and second nodes, or as a shunt inductance path between the ground and a node along the inductance path.

Abstract: Apparatus and methods related to beamforming of harmonics are provided herein. In certain implementations, a communications device for operating in a cellular network is provided. The communications device includes a plurality of signal conditioning circuits configured to generate a plurality of transmit signals, an antenna array configured to radiate a transmit beam and including a plurality of antenna elements each thereof operatively associated with a corresponding one of the plurality of signal conditioning circuits, and a beam control circuit configured to control the plurality of signal conditioning circuits to provide beam steering of the transmit beam based on a direction of one or more harmonic lobes of the transmit beam.

Abstract: Phase shifters for communication systems are provided herein. In certain embodiments, a phase shifter includes a plurality of phase shifting sections and a plurality of selection switches each coupled to a corresponding one of the phase shifting sections. The selection switches are formed on a semiconductor die, and are operable to connect one or more selected phase shifting sections between an input terminal and an output terminal, thereby controlling an overall phase shift provided by the phase shifter.

Abstract: Apparatus and methods for phase shifting are provided herein. In certain embodiments, a phase shifter includes a group of positive phase shifting circuits, a group of negative phase shifting circuits, and a group of selection switches for controlling selection of the positive phase shifting circuits and the negative phase shifting circuits. The selection switches are formed on a semiconductor die, and are operable to connect one or more selected positive phase shifting circuits and/or one or more selected negative phase shifting circuits between an input terminal and an output terminal, thereby controlling an overall phase shift provided by the phase shifter.

Abstract: In some embodiments, an attenuator for electronic application can include a first group of attenuation steps, with each configured to switchably provide a first fixed attenuation value. The attenuator can further include a second group of attenuation steps, with each configured to switchably provide a second fixed attenuation value. Magnitude of the second fixed attenuation value can be less than magnitude of the first fixed attenuation value. The attenuator can be configured to be capable of providing a total attenuation value from approximately zero to a sum of the attenuation steps of the first group and the second group in increments of the second fixed attenuation value.

Abstract: A receiving system includes a controller that selectively activates one or more of a plurality of paths between an input of a first multiplexer and an output of a second multiplexer. The receiving system includes a plurality of bandpass filters, each one of the bandpass filters being disposed along a corresponding one of the plurality of paths and configured to filter a signal received at the bandpass filter to a respective frequency band. The receiving system also includes a plurality of variable-gain amplifiers (VGAs), each one of the plurality of VGAs disposed along a corresponding one of the plurality of paths and configured to amplify a signal received at the VGA with a gain controlled by an amplifier control signal received from the controller. At least one, but not all, of the VGAs is a fixed-gain amplifier with a bypass switch to selectively bypass the fixed-gain amplifier.

Abstract: Described herein are radio-frequency (RF) modules that include shielding for improved RF performance. The RF modules including a packaging substrate with a receiving system implemented thereon. The RF module includes a shield implemented to provide RF shielding for at least a portion of the receiving system. The receiving system can include any combination of pre-amplifier or post-amplifier bandpass filters, amplifiers, switching networks, impedance matching components, phase-shifting components, input multiplexers, and output multiplexers. The shielding can include a conductive layer within a conformal shielding on an upper side and side walls of the RF module. The shielding can be an overmold formed over the packaging substrate. The conductive layer can be connected to one or more ground planes. The packaging substrate can include contact features on an underside of the substrate for mounting an underside component.

Abstract: A power amplifier system can include a power amplifier that provides amplification to a radio frequency signal associated with a first frequency band and outputs an amplified radio frequency signal. An acoustic wave bandpass filter such as a surface acoustic wave or bulk acoustic wave bandpass filter is arranged in a feedback configuration with respect to the power amplifier. The filter can pass through a portion of the amplified radio frequency signal corresponding to a second frequency to provide negative feedback to the power amplifier, resulting in a reduction in an amount of gain from the power amplifier within the second frequency band.

Abstract: A power amplifier system can be configured to provide amplification to a radio frequency signal associated with a first frequency band and to output an amplified radio frequency signal. The system can include a bandpass filter arranged in a feedback loop with respect to the power amplifier and configured to pass through a portion of the amplified radio frequency signal corresponding to a second frequency band. A first shifter can be positioned in the feedback loop, and an output of the feedback loop can provide negative feedback to an input of the power amplifier.

Abstract: A wireless communication device includes a radio frequency antenna and a transceiver. The transceiver includes a receiver having a switching architecture configured to generate a plurality of output phases within a local oscillator period based on the filtered RF signal and a respective plurality of local oscillator signals. The plurality of output phases can be organized into at least K groups where K is an integer of four or greater, and each nth group of the K groups includes nth and (n+K)th output phases of the plurality of output phases. The receiver can difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases.

Abstract: Systems and methods are provided for reducing the effects of an impedance mismatch between a communications system and a shared communications medium. A communication system, such as a transceiver within a cable modem, switches between various operating modes including a transmit mode, a receive mode, and a standby mode. The standby mode may be used while the transceiver is in an idle state between modes, such as while changing an amplifier gain states in between transmissions. While transitioning between modes, the impedance presented by the communications system can temporarily fluctuate causing unwanted signal reflections to propagate out of the communications system and on to the shared medium. Circuitry within the communications system, such as transmission circuitry including an adjustable attenuator, may be placed into a hybrid attenuation-isolation mode during the transition causing the magnitude of any unwanted signal reflections to be attenuated and reducing the impact on the shared medium.

Abstract: Systems and methods for suppressing transient outputs from an amplifier system are provided. An amplifier having a plurality of bias levels may be controlled to initiate a change in the level of a bias signal provided to the amplifier. The level of the bias signal is ramped from an initial bias level to a final bias level over numerous steps. The steps include at least one step in which the level of the bias signal is between the initial bias level and the final bias level. An amplifier system having multiple stages may be controlled to enable each stage and selectively couple each stage in a sequence that couples an output stage to an output terminal at the completion of the sequence.

Abstract: An ‘L’ shaped dynamically configurable impedance matching circuit is presented herein. The circuit can include a series element and a shunt element. The shunt element in the L-shaped impedance matching circuit can be moved or modified based on the impedance of the circuit elements in electrical communication with each side of the impedance matching circuit. Thus, in some cases, the impedance matching circuit may be a flexible circuit that can be dynamically modified based on the environment or configuration of the wireless device that includes the impedance matching circuit.

Abstract: Integrated Doherty power amplifiers are provided herein. In certain implementations, a Doherty power amplifier includes a carrier amplification stage that generates a carrier signal, a peaking amplification stage that generates a peaking signal, and an antenna structure that combines the carrier signal and the peaking signal. The antenna structure radiates a transmit wave in which the carrier signal and the peaking signal are combined with a phase shift.