A wireless communication device includes an amplifier block amplifying a radio frequency (RF) input signal. The amplifier block includes: a first amplification unit and a second amplification unit. The first amplification unit amplifies the RF input signal to generate a first RF amplified signal including a first non-linearity factor and a second RF amplified signal including a second non-linearity factor, and combines the first and second RF signals to generate a third RF amplified signal. The second amplification unit receives and amplifies the third RF amplified signal to output an RF output signal corresponding to the at least one carrier.

Circuits, devices and methods are disclosed, including radio-frequency circuitry comprising a polar modulator configured to invert a sampled transmitted signal into an inverted sampled transmitted signal, a signal combiner configured to combine the inverted sampled transmitted signal with a received signal and a control logic circuit coupled to the polar modulator, the control logic circuit configured to adjust one or more tuning parameters of the polar modulator for inverting the sampled transmitted signal.

A semiconductor devices comprises a first member including a first circuit partially formed by an elemental semiconductor element at a surface layer, a first conductive raised portion at the first member, and a second member smaller than the first member in plan view joined to the first member. The second member includes a second circuit partially formed by a compound semiconductor element. A second conductive raised portion is at the second member. A power amplifier includes a first-stage amplifier circuit included in the first or second circuit and a second-stage amplifier circuit included in the second circuit. The first circuit includes a first switch for inputting to the first-stage amplifier circuit a radio-frequency signal inputted to a selected contact, a control circuit to control the first- and second-stage amplifier circuits, and a second switch for outputting from a selected contact a radio-frequency signal outputted by the second-stage amplifier circuit.

A system includes an operational amplifier which includes a first amplifier input, a second amplifier input and an amplifier output. The system includes a first switch which includes a first terminal and includes a second terminal coupled to the first amplifier input. The system includes a second switch which includes a first terminal coupled to the first amplifier input and a second terminal coupled to the second amplifier input. The system includes a first bias current source coupled between the first amplifier input and a common potential and includes a second bias current source coupled between the first terminal of the first switch and the common potential. The system includes a feedback path between the amplifier output and the first amplifier input.

Aspects of this disclosure relate to a filter for a carrier aggregation system. The filter is configured to pass a first band of a carrier aggregation signal. The filter includes a surface acoustic wave device that includes a quartz substrate, an interdigital transducer electrode, and a lithium-based piezoelectric layer positioned between the quartz substrate and the interdigital transducer electrode. The surface acoustic wave device is configured to suppress a higher order spurious mode corresponding to a second band of the carrier aggregation signal.

A circuit device includes an analog front-end circuit that receives a target signal is input, and a processing circuit that performs arithmetic processing based on an output signal from the analog front-end circuit. The analog front-end circuit includes a plurality of comparator circuits that compare the voltage level of the target signal to a plurality of threshold voltages and output a plurality of comparison result signals. The processing circuit obtains the transition timing of the target signal based on the comparison result signals and delayed-time information of the analog front-end circuit.

Apparatus and methods for envelope tracking systems with automatic mode selection are provided herein. In certain configurations, a power amplifier system includes a power amplifier configured to provide amplification to a radio frequency signal and to receive power from a power amplifier supply voltage, and an envelope tracker including a signal bandwidth detection circuit configured to generate a detected bandwidth signal based on processing an envelope signal corresponding to an envelope of the radio frequency signal. The envelope tracker further includes a switch bank configured to receive a plurality of regulated voltages, a filter configured to filter an output of the switch bank to generate the power amplifier supply voltage, and a mode control circuit configured to control a filtering characteristic of the filter based on the detected bandwidth signal.

A semiconductor device formed on a silicon on insulator substrate includes an input node to receive a first signal, such as a high frequency signal, and an output node to output a second signal corresponding to the first signal. A first transistor has a gate that receives the first signal from the input node and thereby outputs an amplified first signal. A second transistor is connected between a drain of the first transistor and the output node. An inductor is connected between a source of the first transistor and a ground potential. A capacitor connected is between the gate of the first transistor and the input node. An electrostatic discharge (ESD) protective element is connected between a first node and a second node. The first node is between the inductor and the first transistor, and the second node is between the input node and the capacitor.

In a sensor reader, an IC chip has a function for amplifying and outputting a sensor signal from each sensor element included in a sensor array, and includes a plurality of channel amplifiers connected each of the sensor elements. When an output switch is closed and the IC chip is in the outputting state, channel switches operate sequentially, and sensor amplification signals are output sequentially from the channel amplifiers. When the output switch is open and the IC chip is in the non-outputting state, a bias current of an operational amplifier of the channel amplifier is decreased, the IC chip is set to a low power consumption state, and gain of the operational amplifier is decreased.

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.