A power supply circuit in a wireless communications system includes an envelope tracking modulator coupled to a first power amplifier circuit and a second power amplifier circuit, so that the power supply circuit supplies power to the first power amplifier circuit and the second power amplifier circuit. When a transmit signal output by a processor is within a first bandwidth range, the power supply circuit supplies power to the first power amplifier circuit, and the first power amplifier circuit amplifies power of the transmit signal. When the transmit signal output by the processor meets a second bandwidth range, the power supply circuit supplies power to the second power amplifier circuit, and the second power amplifier circuit amplifies the transmit signal.

A radio frequency module includes a module substrate; a power amplifier disposed on or over the module substrate, amplifies a radio frequency signal, and outputs the amplified radio frequency signal as the first transmission signal; a power amplifier disposed on or over the module substrate, amplifies a radio frequency signal, and outputs the amplified radio frequency signal as the second transmission signal; a temperature sensor disposed on or over the module substrate; and a PA control circuit disposed on or over the module substrate and controls amplification operations of the power amplifiers according to a measurement value of the temperature sensor. The maximum output power of the power amplifier is greater than the maximum output power of the power amplifier, and the distance between the temperature sensor and the power amplifier is less than or equal to the distance between the temperature sensor and the power amplifier.

A radio frequency module including a module substrate including a first principal surface and a second principal surface; a power amplifier; an inductor disposed on the second principal surface and connected to the power amplifier; and an external connection terminal configured to receive a power supply voltage. The first external connection terminal is disposed on the second principal surface and connected to the power amplifier via the inductor.

A multi-band power amplifier module includes at least one transmission input terminal, at least one power amplifier circuit that receives a first transmission signal and a second transmission signal through the at least one transmission input terminal, a first filter circuit that allows the first transmission signal to pass therethrough, a second filter circuit that allows the second transmission signal to pass therethrough, at least one transmission output terminal through which the first and second transmission signals output from the first and second filter circuits are output, a transmission output switch that outputs each of the first and second transmission signals output from the at least one power amplifier circuit to the first filter circuit or the second filter circuit, and a first tuning circuit that adjusts impedance matching between the at least one power amplifier circuit and the at least one transmission output terminal.

Envelope tracking power amplifiers with advanced gain shaping are provided. In certain implementations, a power amplifier system includes a power amplifier that amplifies a radio frequency (RF) signal and an envelope tracker that controls a voltage level of a supply voltage of the power amplifier based on an envelope of the RF signal. The power amplifier system further includes a gain shaping circuit that generates a gain shaping current that changes with the voltage level of the supply voltage from the envelope tracker. For example, the gain shaping circuit can include an analog look-up table (LUT) mapping a particular voltage level of the supply voltage to a particular current level of gain shaping current. Additionally, the gain shaping circuit biases the power amplifier based on the gain shaping current.

In a radio-frequency module, a conductive layer covers a major surface opposite to the mounting board side of a resin layer and a major surface opposite to the mounting board side of an electronic component. The electronic component includes an electronic component body and a plurality of outer electrodes. The electronic component body includes an electrical insulating portion and a conductive portion provided inside the electrical insulating portion, forming at least a portion of a circuit element of the electronic component. The electronic component body has a third major surface and a fourth major surface opposite to each other, and an outer side surface. The third major surface forms the major surface of the electronic component, and the third major surface is in contact with the conductive layer. The plurality of outer electrodes are provided on the fourth major surface, but are not extended over the third major surface.

A radio-frequency module includes a first base, which has at least a part formed of a first semiconductor material and which includes a low-noise amplifier circuit, a second base, which has at least a part formed of a second semiconductor material having a thermal conductivity lower than that of the first semiconductor material and which includes a power amplifier circuit, and a module substrate, which has a principal surface on which the first base and the second base are disposed. The first base is joined to the principal surface with electrodes interposed in between. The second base is disposed between the module substrate and the first base in cross-sectional view, and is joined to the principal surface with an electrode interposed in between. At least a part of the first base overlaps at least a part of the second base in plan view.

A communication system for SAR (Specific Absorption Rate) reduction includes an RF (Radio Frequency), an antenna element, a coupler, and a controller. The RF module provides RF power. The antenna element is excited by the RF module. The coupler is coupled between the RF module and the antenna element. The controller receives antenna information from the coupler. The controller adjusts the level of RF power according to the antenna information.

A transmitter apparatus and method are disclosed. An RF terminal provides an RF signal. A first antenna transmits a first portion of the RF signal and a second antenna transmits a second portion of the RF signal. Directional couplers generate a first monitoring signal and a second monitoring signal. A power comparison operational amplifier receives the first monitoring signal and the second monitoring signal and generates a power difference signal. A phase control operational amplifier receives the power difference signal and a reference input signal and generates a phase control signal. A phase shifter receives the phase control signal, and based on the phase control signal, phase-shifts the RF signal to direct the RF signal to the first antenna, or phase-shifts the RF signal to direct the RF signal to the second antenna.

A wireless single-phase AC-to-AC conversion circuit based on a 2.4G microwave includes a receiving antenna unit, a RF switch unit, a positive voltage rectification unit, a negative voltage rectification unit and an AC synthesis unit. An output port of the receiving antenna unit is connected to the common input port of the RF switch unit. A first microwave output end of the RF switch unit and a second microwave output end of the RF switch unit are correspondingly connected to a microwave input end of the positive voltage rectification unit and a microwave input end of the negative voltage rectification unit, respectively. A DC output end of the positive voltage rectification unit and a DC output end of the negative voltage rectification unit are correspondingly connected to a positive voltage input port of the AC synthesis unit and a negative voltage input port of the AC synthesis unit, respectively.