A wireless communication device includes an antenna, a DPDC, an amplifier, a coupler, and a bias output unit. The DPDC performs distortion compensation on a transmission signal based on a feedback signal. The amplifier amplifies the transmission signal subjected to the distortion compensation by the DPDC. The coupler splits the transmission signal amplified by the amplifier into a transmission signal output to the antenna and the feedback signal input to the DPDC. The DPDC measures an index based on a reflected wave obtained by reflection of the transmission signal split by the coupler from the antenna. The bias output unit applies a bias voltage for controlling an efficiency of an amplifier to the amplifier in accordance with the index measured by the DPDC.

A power amplifier including a power amplifier stage. The power amplifier stage may be configured to receive a signal, amplify the signal at saturation with substantially zero amplitude-phase (AM-PM) distortion, and output the amplified signal as an output signal. The power amplifier may be a single stage power amplifier or a multi-stage power amplifier.

A radio-frequency module includes a switch; power amplifiers; a transmission filter that has a passband including a transmission band of a communication band A included in a communication band group X and that has one end connected to an antenna connection terminal via the switch and the other end connected to an output of the power amplifier; a transmission filter that has a passband including a transmission band of a communication band C included in a communication band group Y lower than the communication band group X and that has one end connected to the antenna connection terminal via the switch and the other end connected to an output of the power amplifier; and a module substrate. In a plan view of the module substrate, a distance between the power amplifier and the switch is shorter than a distance between the power amplifier and the switch.

The radio frequency front-end systems herein include modules having bandwidth controllable components, such as amplifier and filters. By implementing the modules with bandwidth control, the same module can be used for operation of multiple frequency bands including a first frequency band and a second frequency band. Thus, when implementing features such as carrier aggregation, multiple-input multiple-output (MIMO), and/or sounding resource signaling (SRS) for supporting the multiple frequency bands, the total number of modules used can be reduced and/or additional feature support can be provided compared to an implementation in which each module supports a single frequency band.

Techniques for controlling remote antenna systems. An example method of receiving radio frequency signals with a remote antenna module includes providing a first signal to a remote receiver on a conductor, receiving a control signal from the remote receiver on the conductor, wherein the control signal is a bias voltage on the conductor, and providing a second signal on the conductor in response to receiving the control signal.

A millimeter-wave (MMW) communication system may include an antenna array structure operating within a MMW band, having both a first antenna coupling point and a second antenna coupling point, whereby the first and the second location of the antenna coupling points are within a coplanar surface on which the antenna array structure is formed. The system may further include a first MMW transmitter that couples a first data modulated MMW signal to the first antenna coupling point and a second MMW transmitter that couples a second data modulated MMW signal to the second antenna coupling point. Coupling the first data modulated MMW signal to the first antenna coupling point generates a first MMW radio signal transmitted at a first propagation direction and coupling the second data modulated MMW signal to the second antenna coupling point generates a second MMW radio signal transmitted at a second propagation direction.

A radio frequency module includes a module board, a transmission power amplifier, a first inductance element mounted on a first principal surface and connected to an output terminal of the transmission power amplifier, a reception low-noise amplifier, and a second inductance element mounted on a first principal surface connected to an input terminal of the reception low-noise amplifier. In a plan view of the module board, a conductive member mounted on the first principal surface is disposed between the first inductance element and the second inductance element.

Radio frequency front-end systems with filter reuse. In certain embodiments, a front-end system includes a filter, a low noise amplifier (LNA), and a switch interposed between the filter and an input to the LNA. In a first state of the switch, the filter serves to filter a radio frequency signal that is amplified by the LNA. The front-end system further includes a power amplifier that is coupled to the switch. Additionally, in a second state of the switch, the filter serves to filter an amplified radio frequency transmit signal provided by the power amplifier. Accordingly, a filter along a receive path of the front-end system is reused for transmit.

This disclosure describes apparatuses, methods, and techniques for supporting multiple protocols with selective amplification, such as 5 GHz Wi-Fi®, 2.4 GHz Wi-Fi®, 2.4 GHz Bluetooth Classic®, 2.4 GHz BLE®, and/or 2.4 GHz IEEE 802.15.4 (e.g., Thread® or ZigBee®) protocols. In more detail, the disclosure describes a multi-protocol transceiver system that includes a front-end architecture, which enables the multi-protocol transceiver system to transmit and receive the wireless communication signals according to the multiple protocols. The multi-protocol transceiver system may utilize one or more antennas to transmit and receive the multiple protocols.

A radio frequency module includes a first transmission power amplifier configured to amplify a radio frequency signal of a first communication band, a second transmission power amplifier configured to amplify a radio frequency signal of a second communication band, and a module board which includes a first principal surface and a second principal surface on opposite sides of the module board, and on which the first transmission power amplifier and the second transmission power amplifier are mounted. The first transmission power amplifier is disposed on the first principal surface, and the second transmission power amplifier is disposed on the second principal surface.