A semiconductor device and a communication circuit capable of reducing the effect of a noise generated in an inductor are provided. A semiconductor device according to an embodiment includes a substrate, a first circuit disposed in a first area of the substrate, a second circuit disposed in a second area of the substrate, the second circuit being configured to operate selectively with the first circuit, a first inductor disposed in the second area and connected to the first circuit, and a second inductor disposed in the first area and connected to the second circuit.

An amplifier, communication device and method of amplification are disclosed. An RF signal is amplified by a Doherty power amplifier (DPA). The DPA has a main amplifier with a Class-AB amplifier in parallel with a Class-C amplifier. When the RF signal power is smaller than 6 dB PBO, the Class-AB amplifier provides the main amplifier amplification; when the RF signal is between 6 dB PBO and 0 dB PBO, both the Class-AB and Class-C amplifiers provide the main amplifier amplification.

An amplifier, communication device and method of amplification are disclosed. An RF signal is amplified by a Doherty power amplifier (DPA). The DPA has a main amplifier with a Class-AB amplifier in parallel with a Class-C amplifier. When the RF signal power is smaller than 6 dB PBO, the Class-AB amplifier provides the main amplifier amplification; when the RF signal is between 6 dB PBO and 0 dB PBO, both the Class-AB and Class-C amplifiers provide the main amplifier amplification.

An electronic device is provided. The electronic device includes a first antenna, a second antenna, a transmission/reception path unit, a first reception path unit, a second reception path unit including a low noise amplifier (LNA), a signal path selection unit configured to connect each of the first antenna and the second antenna to the transmission/reception path unit, the first reception path unit, or the second reception path unit, and a radio frequency integrated circuit (RFIC) module or a processor including the RFIC module configured to control the signal path selection unit to have a first state in which the first antenna is connected to the transmission/reception path unit and the second antenna is connected to the second reception path unit or control the signal path selection unit to have a second state in which the first antenna is connected to the first reception path unit and the second antenna is connected to the transmission/reception path unit.

An electronic device is provided. The electronic device includes a first antenna, a second antenna, a transmission/reception path unit, a first reception path unit, a second reception path unit including a low noise amplifier (LNA), a signal path selection unit configured to connect each of the first antenna and the second antenna to the transmission/reception path unit, the first reception path unit, or the second reception path unit, and a radio frequency integrated circuit (RFIC) module or a processor including the RFIC module configured to control the signal path selection unit to have a first state in which the first antenna is connected to the transmission/reception path unit and the second antenna is connected to the second reception path unit or control the signal path selection unit to have a second state in which the first antenna is connected to the first reception path unit and the second antenna is connected to the transmission/reception path unit.

A digital frontend circuit for a radio frequency (RF) comprises a digital predistortion (DPD) block, a plurality of sub-sample delay elements, and a selection circuit. The DPD block for computing predistorted transmit signals according to a Volterra series approximation model. The DPD block has an input for receiving input samples at a first sample rate and an output for providing the predistorted transmit signals at the first sample rate. Each of the sub-sample delay elements provides a delay to an input sample as specified by the Volterra series approximation model, where each of the delays is based on a fraction of the first sample rate. The selection circuit selects one of the plurality of sub-sample delay elements in response to a selection signal from the digital predistortion block. The selection signal for selecting a delay as specified by the Volterra series approximation model.

Apparatus and methods for power amplifier bias modulation for low bandwidth envelope tracking are provided herein. In certain embodiments, a power amplifier system for a mobile device includes a power amplifier that amplifies an RF signal and a low bandwidth envelope tracker that generates a power amplifier supply voltage for the power amplifier based on an envelope of the RF signal. The envelope tracking system further includes a bias modulation circuit that modulates a bias signal of the power amplifier based on a voltage level of the power amplifier supply voltage.

Apparatus and methods for power amplifier bias modulation for low bandwidth envelope tracking are provided herein. In certain embodiments, a power amplifier system for a mobile device includes a power amplifier that amplifies an RF signal and a low bandwidth envelope tracker that generates a power amplifier supply voltage for the power amplifier based on an envelope of the RF signal. The envelope tracking system further includes a bias modulation circuit that modulates a bias signal of the power amplifier based on a voltage level of the power amplifier supply voltage.

An apparatus includes a radio-frequency (RF) circuit, which includes a power amplifier coupled to receive an RF input signal and to provide an RF output signal in response to a modified bias signal. The RF circuit further includes a bias path circuit coupled to modify a bias signal as a function of a characteristic of an input signal to generate the modified bias signal. The bias path circuit provides the modified bias signal to the power amplifier.

A method for predistorting an input signal of an amplifier device comprises evaluating a selection criterion for a computational model of the amplifier device. The computational model provides an output signal of the amplifier device for the input signal of the amplifier device. Further, the method comprises selecting between a first computational model of the amplifier device and a second computational model of the amplifier device based on the evaluated selection criterion. Additionally, the method comprises predistorting the input signal of the amplifier device using the selected computational model.