Abstract: Provided is a power amplification circuit that includes: an amplifier that amplifies an input signal and outputs an amplified signal; a first bias circuit that supplies a first bias current or voltage to the amplifier; a second bias circuit that supplies a second bias current or voltage to the amplifier; a first control circuit that controls the first bias current or voltage; and a second control circuit that controls the second bias current or voltage. The current supplying capacity of the first bias circuit is different from the current supplying capacity of the second bias circuit.

Abstract: A communication unit includes the following elements. A first transmit circuit outputs a first signal or a second signal from a first input signal. A first amplifier amplifies the first signal and outputs a first amplified signal. A first signal generating circuit generates a third signal having a frequency higher than a frequency of the second signal, based on the second signal and a first reference signal. A first filter circuit receives the third signal and allows one of a frequency component representing a sum of the frequency of the second signal and a frequency of the first reference signal and a frequency component representing a difference therebetween to pass through the first filter circuit and attenuates the other one of the frequency components. A second amplifier amplifies the third signal output from the first filter circuit and outputs a second amplified signal.

Abstract: A communication unit includes the following elements. A first transmit circuit outputs a first signal or a second signal from a first input signal. A first amplifier amplifies the first signal and outputs a first amplified signal. A first signal generating circuit generates a third signal having a frequency higher than a frequency of the second signal, based on the second signal and a first reference signal. A first filter circuit receives the third signal and allows one of a frequency component representing a sum of the frequency of the second signal and a frequency of the first reference signal and a frequency component representing a difference therebetween to pass through the first filter circuit and attenuates the other one of the frequency components. A second amplifier amplifies the third signal output from the first filter circuit and outputs a second amplified signal.

Abstract: Provided is a power amplification circuit that includes: an amplifier that amplifies an input signal and outputs an amplified signal; a first bias circuit that supplies a first bias current or voltage to the amplifier; a second bias circuit that supplies a second bias current or voltage to the amplifier; a first control circuit that controls the first bias current or voltage; and a second control circuit that controls the second bias current or voltage. The current supplying capacity of the first bias circuit is different from the current supplying capacity of the second bias circuit.

Abstract: Provided is a power amplification circuit that includes: an amplifier that amplifies an input signal and outputs an amplified signal; a first bias circuit that supplies a first bias current or voltage to the amplifier; a second bias circuit that supplies a second bias current or voltage to the amplifier; a first control circuit that controls the first bias current or voltage; and a second control circuit that controls the second bias current or voltage. The current supplying capacity of the first bias circuit is different from the current supplying capacity of the second bias circuit.

Abstract: A communication unit includes the following elements. A first transmit circuit outputs a first signal or a second signal from a first input signal. A first amplifier amplifies the first signal and outputs a first amplified signal. A first signal generating circuit generates a third signal having a frequency higher than a frequency of the second signal, based on the second signal and a first reference signal. A first filter circuit receives the third signal and allows one of a frequency component representing a sum of the frequency of the second signal and a frequency of the first reference signal and a frequency component representing a difference therebetween to pass through the first filter circuit and attenuates the other one of the frequency components. A second amplifier amplifies the third signal output from the first filter circuit and outputs a second amplified signal.

Abstract: A communication unit includes the following elements. A first transmit circuit outputs a first signal or a second signal from a first input signal. A first amplifier amplifies the first signal and outputs a first amplified signal. A first signal generating circuit generates a third signal having a frequency higher than a frequency of the second signal, based on the second signal and a first reference signal. A first filter circuit receives the third signal and allows one of a frequency component representing a sum of the frequency of the second signal and a frequency of the first reference signal and a frequency component representing a difference therebetween to pass through the first filter circuit and attenuates the other one of the frequency components. A second amplifier amplifies the third signal output from the first filter circuit and outputs a second amplified signal.

Abstract: A communication unit includes the following elements. A first transmit circuit outputs a first signal or a second signal from a first input signal. A first amplifier amplifies the first signal and outputs a first amplified signal. A first signal generating circuit generates a third signal having a frequency higher than a frequency of the second signal, based on the second signal and a first reference signal. A first filter circuit receives the third signal and allows one of a frequency component representing a sum of the frequency of the second signal and a frequency of the first reference signal and a frequency component representing a difference therebetween to pass through the first filter circuit and attenuates the other one of the frequency components. A second amplifier amplifies the third signal output from the first filter circuit and outputs a second amplified signal.

Abstract: A communication unit includes the following elements. A first transmit circuit outputs a first signal or a second signal from a first input signal. A first amplifier amplifies the first signal and outputs a first amplified signal. A first signal generating circuit generates a third signal having a frequency higher than a frequency of the second signal, based on the second signal and a first reference signal. A first filter circuit receives the third signal and allows one of a frequency component representing a sum of the frequency of the second signal and a frequency of the first reference signal and a frequency component representing a difference therebetween to pass through the first filter circuit and attenuates the other one of the frequency components. A second amplifier amplifies the third signal output from the first filter circuit and outputs a second amplified signal.

Abstract: Provided is a power amplification circuit that includes: an amplifier that amplifies an input signal and outputs an amplified signal; a first bias circuit that supplies a first bias current or voltage to the amplifier; a second bias circuit that supplies a second bias current or voltage to the amplifier; a first control circuit that controls the first bias current or voltage; and a second control circuit that controls the second bias current or voltage. The current supplying capacity of the first bias circuit is different from the current supplying capacity of the second bias circuit.

Abstract: Provided is a power amplification circuit that includes: an amplifier that amplifies an input signal and outputs an amplified signal; a first bias circuit that supplies a first bias current or voltage to the amplifier; a second bias circuit that supplies a second bias current or voltage to the amplifier; a first control circuit that controls the first bias current or voltage; and a second control circuit that controls the second bias current or voltage. The current supplying capacity of the first bias circuit is different from the current supplying capacity of the second bias circuit.

Abstract: Provided is a power amplification circuit that includes: an amplifier that amplifies an input signal and outputs an amplified signal; a first bias circuit that supplies a first bias current or voltage to the amplifier; a second bias circuit that supplies a second bias current or voltage to the amplifier; a first control circuit that controls the first bias current or voltage; and a second control circuit that controls the second bias current or voltage. The current supplying capacity of the first bias circuit is different from the current supplying capacity of the second bias circuit.

Abstract: Provided is a bias circuit that supplies a first bias current or voltage to an amplifier that amplifies a radio frequency signal. The bias circuit includes: an FET that has a power supply voltage supplied to a drain thereof and that outputs the first bias current or voltage from a source thereof; a first bipolar transistor that has a collector thereof connected to a gate of the FET, that has a base thereof connected to the source of the FET, that has a common emitter and that has a constant current supplied to the collector thereof; and a first capacitor that has one end thereof connected to the collector of the first bipolar transistor and that suppresses variations in a collector voltage of the first bipolar transistor.

Abstract: A communication unit includes the following elements. A first transmit circuit outputs a first signal or a second signal from a first input signal. A first amplifier amplifies the first signal and outputs a first amplified signal. A first signal generating circuit generates a third signal having a frequency higher than a frequency of the second signal, based on the second signal and a first reference signal. A first filter circuit receives the third signal and allows one of a frequency component representing a sum of the frequency of the second signal and a frequency of the first reference signal and a frequency component representing a difference therebetween to pass through the first filter circuit and attenuates the other one of the frequency components. A second amplifier amplifies the third signal output from the first filter circuit and outputs a second amplified signal.

Abstract: A communication unit includes the following elements. A first transmit circuit outputs a first signal or a second signal from a first input signal. A first amplifier amplifies the first signal and outputs a first amplified signal. A first signal generating circuit generates a third signal having a frequency higher than a frequency of the second signal, based on the second signal and a first reference signal. A first filter circuit receives the third signal and allows one of a frequency component representing a sum of the frequency of the second signal and a frequency of the first reference signal and a frequency component representing a difference therebetween to pass through the first filter circuit and attenuates the other one of the frequency components. A second amplifier amplifies the third signal output from the first filter circuit and outputs a second amplified signal.

Abstract: The present invention is to provide a technique which optimizes a gate resistor of a bias circuit to thereby make it possible to greatly improve a distortion characteristic of a power amplifier. A bias circuit used as for biasing the gate of a final-stage power transistor is included in a power amplifier provided in a communication mobile system. In the bias circuit, an inductance and a resistor are series-connected between a power supply voltage and the gate of the power transistor. The resistance value of the resistor is set to approximately the same order as an input impedance of the power transistor. When the input impedance of the power transistor is about 10? or so, for example, the resistor is set to about a few ? to about 100?. Thus, the gain of the power transistor at a low-frequency band can greatly be suppressed.

Abstract: The present invention is to provide a technique which optimizes a gate resistor of a bias circuit to thereby make it possible to greatly improve a distortion characteristic of a power amplifier. A bias circuit used as for biasing the gate of a final-stage power transistor is included in a power amplifier provided in a communication mobile system. In the bias circuit, an inductance and a resistor are series-connected between a power supply voltage and the gate of the power transistor. The resistance value of the resistor is set to approximately the same order as an input impedance of the power transistor. When the input impedance of the power transistor is about 10? or so, for example, the resistor is set to about a few ? to about 100?. Thus, the gain of the power transistor at a low-frequency band can greatly be suppressed.

Abstract: The present invention is to provide a technique which optimizes a gate resistor of a bias circuit to thereby make it possible to greatly improve a distortion characteristic of a power amplifier. A bias circuit used as for biasing the gate of a final-stage power transistor is included in a power amplifier provided in a communication mobile system. In the bias circuit, an inductance and a resistor are series-connected between a power supply voltage and the gate of the power transistor. The resistance value of the resistor is set to approximately the same order as an input impedance of the power transistor. When the input impedance of the power transistor is about 10? or so, for example, the resistor is set to about a few ? to about 100?. Thus, the gain of the power transistor at a low-frequency band can greatly be suppressed.

Abstract: A high frequency power amplifier module of a multistage amplifier construction comprising: an input terminal; an output terminal; a control terminal; and a mode switching terminal. The first amplification stage includes a dual gate FET, and a bias voltage according to a signal is applied to the first gate and the second gate of the dual gate FET from the control terminal and the mode switching terminal, and a radio signal from the input terminal is applied to the second gate such as the source of the dual gate FET. In dependence upon the signal from the mode switching terminal, the mode of the high frequency power amplifier module is for the GSM (i.e., for a non-linear amplifying action) and for the EDGE (for a linear amplifying action).

Abstract: The present invention is to provide a technique which optimizes a gate resistor of a bias circuit to thereby make it possible to greatly improve a distortion characteristic of a power amplifier. A bias circuit used as for biasing the gate of a final-stage power transistor is included in a power amplifier provided in a communication mobile system. In the bias circuit, an inductance and a resistor are series-connected between a power supply voltage and the gate of the power transistor. The resistance value of the resistor is set to approximately the same order as an input impedance of the power transistor. When the input impedance of the power transistor is about 10 ? or so, for example, the resistor is set to about a few ? to about 100 ?. Thus, the gain of the power transistor at a low-frequency band can greatly be suppressed.