Abstract: Reconfigurable patch antenna systems are provided herein. In certain embodiments, a mobile device includes a patch antenna configured to handle a radio frequency signal at a signal feed. The patch antenna includes a plurality of antenna segments. The front-end system further includes a plurality of switches each configured to control connection of a respective one of the first plurality of antenna segments to the first signal feed, and a control circuit configured to control the plurality of switches to provide a frequency adjustment to the patch antenna.

Abstract: Apparatus and methods for wirelessly communicating using antennas are disclosed. In certain embodiments, an antenna system includes a first radio frequency signal conditioning circuit configured to condition a first radio frequency signal of a first frequency, a plurality of second radio frequency signal conditioning circuits configured to condition a plurality of second radio frequency signals of a second frequency that is greater than the first frequency, a plurality of switches operable in a first mode and a second mode, and an antenna array of including a plurality of antenna elements interconnect by the plurality of switches. The antenna array is operable to handle the first radio frequency signal in the first mode, and to handle the plurality of second radio frequency signals in the second mode.

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: 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: 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: 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: Systems and methods for differential antenna driving are provided. In one aspect, a front end system includes at least one power amplifier configured to receive a first transmit radio frequency signal from a baseband processor, amplify the first transmit radio frequency signal, and output the amplified first transmit radio frequency signal. The front end system further includes at least one balun configured to receive the amplified first transmit radio frequency signal. The at least one balun includes a positive output coupled to a first monopole of at least one antenna and a negative output coupled to a second monopole of the at least one antenna.

Abstract: Systems and methods for differential antenna driving are provided. In one aspect, a front end system includes at least one power amplifier configured to receive a first transmit radio frequency signal from a baseband processor, amplify the first transmit radio frequency signal, and output the amplified first transmit radio frequency signal. The front end system further includes at least one balun configured to receive the amplified first transmit radio frequency signal. The at least one balun includes a positive output coupled to a first monopole of at least one antenna and a negative output coupled to a second monopole of the at least one antenna.

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: 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: A method of adjusting an impedance of a power amplifier of a radio frequency system for matching with an antenna switch die is disclosed. In one aspect, the method includes connecting the power amplifier to the antenna switch die via an impedance adjustment circuit, the impedance adjustment circuit including an input node, an output node, a plurality of electrical components arranged between the input node and the output node, and at least one switch configured to selectively electrically connect at least one of the electrical components to the input node and the output node. The method further includes determining an Error Vector Magnitude of the radio frequency system for each of a plurality of states of the at least one switch, and controlling the at least one switch to enter the state of the plurality of states that minimizes the Error Vector Magnitude of the radio frequency system.

Abstract: A power amplifier impedance adjustment circuit is disclosed. In one aspect, the impedance adjustment circuit includes an input node configured to receive a radio frequency (RF) signal from a power amplifier, an output node configured to provide the RF signal to an antenna switch die, a plurality of electrical components arranged between the input node and the output node, and at least one switch configured to selectively electrically connect at least one of the electrical components to the input node and the output node. For each state of the at least one switch, the impedance adjustment circuit is configured to adjust an impedance of the power amplifier from a natural tune point in a direction towards a target tuned impedance point when viewed on a Smith chart.

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: A switching circuit can be provided for a coupling circuit having a common node and configured to couple the common node to a first group of filters through a first path and to couple the common node to a second group of one or more filters through a second path. The coupling circuit can be further configured such that an impedance provided by each filter of the first group for a signal in each band of the second group results in the signal being sufficiently excluded from the first path, and such that an impedance provided by each filter of the second group for a signal in each band of the first group results in the signal being sufficiently excluded from the second path. The switching circuit can be configured to provide a filter selection functionality along either or both of the first and second paths.

Abstract: A half-bride combiner can be implemented as a coupling circuit having a common node and configured to couple the common node to one of first and second groups of filters through a first path and to couple the common node to the other group through a second path. The coupling circuit can be further configured such that the impedance provided by each filter of the one of the first and second groups for a signal in each band of the other group results in the signal being sufficiently excluded from the first path.

Abstract: An architecture can include a first group of filters each configured to support a band such that a first frequency range covers the respective bands, and a second group of one or more filters each configured to support a band such that a second frequency range covers the respective one or more bands. Each filter of the first group can be configured to provide an impedance at or near a short circuit impedance for a signal in each band of the second group, and each filter of the second group can be configured to provide an impedance at or near a short circuit impedance for a signal in each band of the first group. The filters of the first and second groups can be implemented as one or more multiplexers. The architecture can further include a coupling circuit having a common node and configured to couple the common node to the one or more multiplexers through a first path and a second path.

Abstract: A coupling circuit can be configured to couple a common node to a first group of filters through a first path and to couple the common node to a second group of one or more filters through a second path. The coupling circuit can be configured such that an impedance provided by each filter of the first group for a signal in each band of the second group results in the signal being sufficiently excluded from the first path, and such that an impedance provided by each filter of the second group for a signal in each band of the first group results in the signal being sufficiently excluded from the second path. The first path can present a first impedance to the coupling circuit, and the second path can present a second impedance to the coupling circuit, such that complex part of the first impedance is a conjugate of complex part of the second impedance.

Abstract: A bridge combiner can be implemented as a coupling circuit that includes a common node and configured to couple the common node to a first group of filters through a first path and to couple the common node to a second group of one or more filters through a second path. The coupling circuit can include a resonator such that an impedance provided by each filter of the first group for a signal in each band of the second group results in the signal being sufficiently excluded from the first path, and such that an impedance provided by each filter of the second group for a signal in each band of the first group results in the signal being sufficiently excluded from the second path.

Abstract: A semiconductor-on-insulator die can include a power amplifier configured to amplify a radio frequency input signal having a fundamental frequency. The die can further include an output matching circuit including first and second second-order harmonic rejection circuits configured to resonate at about two times the fundamental frequency and a third order harmonic rejection circuit configured to resonate at about three times the fundamental frequency.

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.