Abstract: A power amplifier apparatus, includes an envelope tracking (ET) current bias circuit configured to generate a first ET bias current by calculating a direct current DC, based on a reference voltage, and an ET current, based on an ET voltage, according to an envelope of an input signal; and a power amplifier circuit having a bipolar junction transistor supplied with the first ET bias current and a power voltage to amplify the input signal, wherein an average current of the first ET bias current is controlled to be substantially constant.

Abstract: A control buffer circuit includes a voltage detection circuit configured to detect whether a received voltage is a negative voltage or a ground voltage and provide a voltage detection signal based on a result of the detecting, and a buffer circuit configured to provide a switching signal based on the voltage detection signal, wherein the switching signal comprises a positive voltage as a switching-on level voltage and includes one or more of the ground voltage and the negative voltage as a switching-off level voltage.

Abstract: An envelope tracking (ET) bias circuit includes a detection circuit configured to select an ET operation voltage input through a first input terminal of the detection circuit, or an envelope signal detected from a radio frequency (RF) signal input through a second input terminal of the detection circuit, in response to a first control signal, to and output he selected one of the ET operation voltage and the envelope signal as a detection signal; an amplification circuit configured to amplify the detection signal, and output the amplified detection signal; and a bias output circuit configured to generate an ET bias current based on the amplified signal, and output the generated ET bias current.

Abstract: An envelope tracking (ET) current bias circuit comprises an envelope detection circuit detecting an ET voltage from an input signal; a first voltage/current converting circuit converting a reference voltage into a direct current (DC) current and adjusting the DC current according to a first control signal; a second voltage/current converting circuit converting the ET voltage into an ET current, adjusting the ET current according to a second control signal, and removing a DC offset current from the ET current to provide an offset compensated ET current; and an arithmetic circuit calculating levels of the offset compensated ET current and the DC current to generate an ET bias current.

Abstract: An envelope tracking (ET) current bias circuit includes a rectifying circuit, a phase compensation circuit, and a voltage/current conversion circuit. The rectifying circuit is configured to detect an envelope voltage from a radio frequency (RF) signal. The phase compensation circuit is configured to compensate for a phase of the envelope voltage in which the phase thereof is delayed in the rectifying circuit to output a phase compensated enveloped voltage. The voltage/current conversion circuit is configured to convert the phase compensated envelope voltage into an ET bias current.

Abstract: A reference current generating circuit includes a current source circuit configured to generate a reference current based on an internal resistor; and a compensation circuit configured to comprise a first compensation circuit comprising a first compensation resistor and a second compensation resistor, and the first compensation resistor and the second compensation resistor are configured to convert the reference current into a first output current and compensate for process variation of the current source circuit.

Abstract: An envelope tracking (ET) bias circuit includes an envelope tracking (ET) bias circuit includes an envelope detection circuit, an envelope amplifier circuit, and an envelope output circuit. The envelope detection circuit is configured to detect an envelope of an input signal, and output an envelope signal based on the detected envelope of the input signal. The envelope amplifier circuit is configured to differentially amplify the envelope signal in response to a first control signal and cancel a direct current (DC) offset of the envelope signal to output an amplified signal from which the DC offset is canceled. The envelope output circuit is configured to generate an ET bias current by selecting either one of a negative signal of the amplified signal and a positive signal of the amplified signal in response to a second control signal.

Abstract: A voltage generation circuit having a temperature compensation function includes a first voltage generation circuit, a second voltage generation circuit, an output voltage control circuit, and a voltage selection circuit. The first voltage generation circuit is configured to generate a first voltage having a zero temperature coefficient, determined in response to a first control signal. The second voltage generation circuit is configured to generate a second voltage having a positive temperature coefficient, determined in response to a second control signal. The output voltage control circuit is configured to control an output of one of the first voltage and the second voltage in response to an operating mode. The voltage selection circuit is configured to select the first voltage or the second voltage in response to the output voltage control circuit.

Abstract: An envelope tracking (ET) current bias circuit comprises an envelope detection circuit detecting an ET voltage from an input signal; a first voltage/current converting circuit converting a reference voltage into a direct current (DC) current and adjusting the DC current according to a first control signal; a second voltage/current converting circuit converting the ET voltage into an ET current, adjusting the ET current according to a second control signal, and removing a DC offset current from the ET current to provide an offset compensated ET current; and an arithmetic circuit calculating levels of the offset compensated ET current and the DC current to generate an ET bias current.

Abstract: A power amplifying apparatus includes a control circuit generating a bias voltage and generating a control signal using a battery voltage and a reference voltage, and a power amplifying circuit boosting the battery voltage according to the control signal to provide an operating voltage, and operating according to the bias voltage and the operating voltage to amplify an input signal, wherein the power amplifying circuit detects the operating voltage and provides a detection voltage to the control circuit, and the control circuit controls the control signal according to the detection voltage.

Abstract: An envelope-tracking current bias circuit includes a first rectifying circuit, a second rectifying circuit, and a first arithmetic circuit. The first rectifying circuit is configured to detect an envelope of an input signal, and provide an envelope detection signal comprising a first direct current (DC) offset voltage. The second rectifying circuit is configured to provide a second DC offset voltage corresponding to the first DC offset voltage. The first arithmetic circuit is configured to provide an envelope signal in which the first DC offset voltage is reduced through subtraction between the envelope detection signal and the second DC offset voltage.

Abstract: A power amplifying apparatus includes a control circuit generating a bias voltage and generating a control signal using a battery voltage and a reference voltage, and a power amplifying circuit boosting the battery voltage according to the control signal to provide an operating voltage, and operating according to the bias voltage and the operating voltage to amplify an input signal, wherein the power amplifying circuit detects the operating voltage and provides a detection voltage to the control circuit, and the control circuit controls the control signal according to the detection voltage.

Abstract: An envelope tracking current bias circuit of a power amplifier circuit including a power amplifier includes a first current source circuit configured to generate a first bias current based on a reference voltage, a second current source circuit configured to generate a second bias current based on an envelope voltage of an input signal, and a bias current generator configured to generate a first envelope tracking bias current based on the first bias current and the second bias current, and supply the first envelope tracking bias current to the power amplifier circuit to reduce amplitude modulation-phase modulation (AM-PM) distortion of the power amplifier circuit.

Abstract: A power amplifying apparatus includes a power circuit configured to generate operating power, a random pulse generation circuit configured to be supplied with the operating power and to generate a pulse width modulation signal of which a pulse width is randomly changed over time using an input radio frequency (RF) signal, and a charge pump circuit configured to be supplied with the operating power and to randomly perform a switching operation according to the pulse width modulation signal to generate a negative voltage.

Abstract: A voltage generation circuit having a temperature compensation function includes a first voltage generation circuit, a second voltage generation circuit, an output voltage control circuit, and a voltage selection circuit. The first voltage generation circuit is configured to generate a first voltage having a zero temperature coefficient, determined in response to a first control signal. The second voltage generation circuit is configured to generate a second voltage having a positive temperature coefficient, determined in response to a second control signal. The output voltage control circuit is configured to control an output of one of the first voltage and the second voltage in response to an operating mode. The voltage selection circuit is configured to select the first voltage or the second voltage in response to the output voltage control circuit.

Abstract: An envelope tracking current bias circuit of a power amplifier circuit including a power amplifier includes a first current source circuit configured to generate a first bias current based on a reference voltage, a second current source circuit configured to generate a second bias current based on an envelope voltage of an input signal, and a bias current generator configured to generate a first envelope tracking bias current based on the first bias current and the second bias current, and supply the first envelope tracking bias current to the power amplifier circuit to reduce amplitude modulation-phase modulation (AM-PM) distortion of the power amplifier circuit.

Abstract: A power amplifier apparatus, includes an envelope tracking (ET) current bias circuit configured to generate a first ET bias current by calculating a direct current DC, based on a reference voltage, and an ET current, based on an ET voltage, according to an envelope of an input signal; and a power amplifier circuit having a bipolar junction transistor supplied with the first ET bias current and a power voltage to amplify the input signal, wherein an average current of the first ET bias current is controlled to be substantially constant.

Abstract: A high-frequency signal predistortion device includes a high-frequency signal estimator, a predistortion estimator, and a predistorter. The high-frequency signal estimator is configured to determine non-linear distortion characteristics of high-frequency signals transmitted by antennas. The predistortion estimator is coupled to the high-frequency signal estimator. The predistortion estimator is configured to determine a predistortion coefficient based on the non-linear distortion characteristics. The predistorter is coupled to the predistortion estimator. The predistorter is configured to distort a base signal of the high-frequency signals based on the predistortion coefficient.

Abstract: An apparatus includes a first predistorter configured to calculate a first predistortion parameter and configured to distort an input signal using the first predistortion parameter to output a first distortion signal, a second predistorter configured to calculate a second predistortion parameter and configured to distort the first distortion signal using the second predistortion parameter to output a second distortion signal, a power supply configured to receive the first distortion signal to generate a first envelope signal, and configured to limit a bandwidth of the first envelope signal to obtain a second envelope signal to supply a source voltage, and a power amplifier configured to receive the source voltage and to output an output signal obtained by amplifying the second distortion signal.

Abstract: A high-frequency signal predistortion device includes a high-frequency signal estimator, a predistortion estimator, and a predistorter. The high-frequency signal estimator is configured to determine non-linear distortion characteristics of high-frequency signals transmitted by antennas. The predistortion estimator is coupled to the high-frequency signal estimator. The predistortion estimator is configured to determine a predistortion coefficient based on the non-linear distortion characteristics. The predistorter is coupled to the predistortion estimator. The predistorter is configured to distort a base signal of the high-frequency signals based on the predistortion coefficient.