Abstract: A radio frequency module including a power amplifier configured to amplify a transmit radio frequency signal and including an output having a first output impedance; and an antenna switch module. The antenna switch module is coupled to the output of the power amplifier and configured to connect at least a first antenna having a first input impedance in parallel with at least a second antenna having a second input impedance to the output of the power amplifier so that a parallel connection of the first and second input impedance matches the first output impedance.

Abstract: A radio frequency front end system includes a ganged filter configured to filter a transmit signal on a plurality of transmit bands. A power amplifier amplifies the transmit signal, and is directly coupled to the ganged filter. Receive circuitry receives a receive signal on a plurality of receive bands. An antenna switch module coupled to the ganged filter and an antenna selectively combines at least one transmit path with at least one receive path according to the plurality of receive bands, the plurality of transmit bands and the plurality of receive bands having no frequency overlap when concurrently active.

Abstract: A radio frequency front end system includes a first transmit path that includes a first transmit filter and is configured to transmit a transmit signal in a first band group to a first antenna. A first receive path includes a first receive filter and is configured to receive a receive signal in the first band group from a second antenna. A second receive path includes a second receive filter and is configured to receive a receive signal in a second band group from the first antenna. A second transmit path includes a second transmit filter and is configured to transmit a transmit signal in the second band group to the second antenna.

Abstract: Multi-level envelope trackers with an analog interface are provided herein. In certain embodiments, an envelope tracking system for generating a power amplifier supply voltage for a power amplifier is provided. The envelope tracking system includes a multi-level supply (MLS) DC-to-DC converter that outputs multiple regulated voltages, and an MLS modulator that controls selection of the regulated voltages over time based on an analog envelope signal corresponding to an envelope of the RF signal amplified by the power amplifier.

Abstract: Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker supplies power to a power amplifier that amplifies an RF signal. The envelope tracker includes a multi-level switching circuit that generates an output current based on an envelope signal indicating an envelope of the RF signal. The envelope tracker further includes a combiner that combines a DC voltage with the output current of the multi-level switching circuit to generate a power amplifier supply voltage for the power amplifier. Accordingly, the output current of the multi-level switching circuit and a DC voltage are combined to generate the power amplifier supply voltage. Implementing the envelope tracking system in this manner can provide enhanced efficiency and/or higher bandwidth relative to an envelope tracking system in which a multi-level switching circuit directly outputs a power amplifier supply voltage.

Abstract: Radio frequency front end modules are provided. In one aspect, a front end system includes at least one power amplifier configured to amplify a transmit radio frequency signal, at least one low noise amplifier configured to receive a receive radio frequency signal, an output node coupled to an antenna. The front end system further includes at least one switch configured to selectively couple the output node to the at least one power amplifier during a transmit period and to the at least one low noise amplifier during a receive period, at least one transmit filter coupled between the power amplifier and the at least one switch, and at least one receive filter coupled between the low noise amplifier and the at least one switch.

Abstract: According to the present disclosure there is provided a front-end module comprising a first antenna port and a second antenna port, a first filter forming a first signal path with the first antenna port and a second filter forming a second signal path with the second antenna port, the first or second filter being an adjustable filter. There is also provided a wireless device.

Abstract: Front-end systems with an adjustable filter architecture are provided. In certain embodiments, a front-end system includes a first bandpass filter with a first passband, a second bandpass filter with a second passband, a stopband filter with a stopband, and switches for controlling connectivity of the filters along transmit and receive paths. The first passband and the second passband include a frequency overlap region, which the stopband at least partially overlaps. The re-configurability of the switches allows for the overall filtering characteristic of the adjustable filter to adjust the duplex gap between transmit and receive passband edges, as well as the passband edges themselves.

Abstract: Apparatus and methods for radio frequency (RF) signal splitting are disclosed. In certain embodiments, a front-end system includes a filter that filters an RF receive signal to generate a differential filtered RF signal between a first output and a second output, a first low noise amplifier (LNA) that generates a first amplified RF signal by amplifying a first component of the differential filtered RF signal received from the first output, a second LNA that generates a second amplified RF signal by amplifying a second component of the differential filtered RF signal received from the second output, a first multi-throw switch that receives the first amplified RF signal, and a second multi-throw switch that receives the second amplified RF signal.

Abstract: Front-end systems with antenna switching that bypasses a transmit band filter are disclosed herein. In certain embodiments, a front-end architecture is based on switching the RF transmit signal behind or before the bandpass filter of the band. This enables the switch-combining and filter ganging used to support carrier aggregation and EN-DC connectivity to be maintained, and the SRS switching done this way for a target TDD band does not impact, interrupt, and/or otherwise re-route the partner bands. Accordingly, both an anchor carrier and a secondary carrier can be maintained without interruption or impact. Furthermore, carrier aggregation features can be maintained and is not interrupted by SRS.

Abstract: Aspects of this disclosure relate to a radio frequency module with a radio frequency coupler and a coupler switching circuit. The coupler switching circuit can provide an indication of radio frequency power generated by the radio frequency coupler to a first input/output port. The coupler switching circuit can also pass an indication of radio frequency power received at the first input/output port to a second input/output port, and pass an indication of radio frequency power received at the second input/output port to the first input/output port.

Abstract: Antenna-plexers for interference cancellation are provided herein. In certain embodiments, a wireless device includes an antenna, an antenna-plexer coupled to the antenna and configured to generate a feedback signal, a transmitter configured to transmit a transmit signal to the antenna by way of the antenna-plexer, a receiver configured to process a receive signal, and a feedback receiver configured to process the feedback signal from the antenna-plexer to provide compensation to the receive signal.

Abstract: Systems and methods for duplexer circuits having signal cancellation paths are provided. In one aspect, a duplexer circuit includes a first transmit filter configured to receive a first radio frequency transmit signal from a power amplifier, and a first receive filter configured to receive the first radio frequency transmit signal from the first transmit filter. The circuit also includes a first low-noise amplifier configured to receive the first radio frequency transmit signal from the first receive filter and amplify the first radio frequency transmit signal and a cancellation path configured to receive a second radio frequency transmit signal from the power amplifier. The circuit further includes a phase shifter configured to apply a phase shift to one or both of the first and second radio frequency transmit signals, and a second low-noise amplifier configured to amplify the second radio frequency transmit signal.

Abstract: A power amplification system may include a shared common cascode input stage. A power amplification system may include a plurality of cascode output stages parallelly connected to the shared common cascode input stage, each cascode output stage associated with a frequency band.

Abstract: Systems and methods for duplexer circuits having signal leakage cancellation are provided. In one aspect, a duplexer circuit includes a transmit path splitter configured to split a radio frequency transmit signal into a pair of radio frequency transmit signals, and a receive path splitter configured to combine a pair of radio frequency receive signals. The duplexer circuit also includes an antenna path splitter configured to combine a pair of radio frequency transmit signals and split a radio frequency receive signal into the pair of radio frequency receive signals, and first and second duplexers. The first duplexer is coupled to a first leg of each of the transmit path splitter, the receive path splitter, and the antenna path splitter, and the second duplexer is coupled to a second leg of each of the transmit path splitter, the receive path splitter, and the antenna path splitter.

Abstract: A system may include a multiplexer coupled to an antenna. The system may further include a combined band filter circuit coupled to the multiplexer and including a filter having a modified filter bandpass extent to include a frequency range of a roaming band, the combined band filter circuit configured to couple a signal associated with the roaming band to the filter.

Abstract: Remote compensators for mobile devices are provided. In certain embodiments, a remote compensator includes a first balun, a cable-side circulator including an output that provides a transmit signal and an input that receives an amplified receive signal, a first phase shifter, a second phase shifter, a first antenna-side circulator, a second antenna-side circulator, transmit amplifier circuitry, and a receive amplifier that generates the amplified receive signal by amplifying a first receive signal from the first antenna-side circulator and a second receive signal from the second antenna-side circulator. The transmit amplifier circuitry includes an input that receives the transmit signal, a first output connected to a first end of a winding of the first balun through the first antenna-side circulator and the first phase shifter, and a second output connected to a second end of the winding of the first balun through the second phase shifter and the second antenna-side circulator.

Abstract: A system may include an antenna. A system may include a module including a power amplifier and an antenna switch. A system may include an antennaplexer communicatively coupled to the antenna and the antenna switch, the antennaplexer positioned between the antenna switch and the antenna in a signal path. A system may include a controller communicatively coupled to the module, the controller configured to control the antenna switch with an override signal.

Abstract: Envelope tracking schemes for Doherty power amplifiers are provided herein. In certain embodiments, an envelope tracking system includes a carrier amplifier that amplifies a first radio frequency signal, a peaking amplifier that amplifies a second radio frequency signal corresponding to a delayed version of the first radio frequency signal, an envelope tracker that generates a first power supply voltage that powers the carrier amplifier, and a delay circuit that delays the first power supply voltage to generate a second power supply voltage that powers the peaking amplifier. The envelope tracker controls a voltage level of the first power supply voltage to track an envelope of the first radio frequency signal. Thus, supply modulation is used to achieve gains in linearity, efficiency, and/or other performance metrics.

Abstract: Radio frequency (RF) communication systems with interference cancellation for coexistence are provided herein. In certain embodiments, an RF communication system includes a transmitter including a power amplifier that amplifies an RF transmit signal, a receiver including a low noise amplifier (LNA) that amplifies an RF receive signal, and an interference cancellation circuit that selects a bandpass filter from a plurality of bandpass filters to filter the RF transmit signal after amplification by the power amplifier. The selected bandpass filter operates in combination with a controllable gain circuit and a controllable phase circuit to generate an analog interference cancellation signal that is injected into the receiver to compensate the RF receive signal for interference arising from the transmitter.