Abstract: An amplification circuit includes an amplifier, a first mirror-branch circuit, a second mirror-branch circuit, a first variable current source, a second variable current source, and an operation amplifier. The amplifier can receive an operation current and an input signal, and output the amplified input signal. The first mirror-branch circuit and the second mirror-branch circuit are coupled to the amplifier. The first variable current source is coupled to the first mirror-branch circuit and provides a first reference current. The second variable current source is coupled to the second mirror-branch circuit and provides a second reference current. The operation amplifier is coupled to the first mirror-branch circuit, the second mirror-branch circuit and the amplifier. The first reference current and the second reference current are related to the operation current.

Abstract: A switch device includes a driver circuit, a switch circuit and a level transition circuit. The driver circuit includes an input terminal for receiving an input signal, an output terminal for outputting an output signal, a first terminal coupled to a first reference terminal, and a second terminal coupled to a second reference terminal. The switch circuit includes a control terminal for receiving the output signal. The level transition circuit includes a first terminal for receiving the output signal, a second terminal coupled to a third reference terminal, and a third terminal for receiving the input signal. In a transition interval, the input signal is transitioned from a first input signal level to a second input signal level, the level transition circuit transitions the output signal from a first output signal level to a third output signal level between the first output signal level and a second output signal level.

Abstract: A bias circuit includes a current mirror circuit, an operational amplifier, and a bias generating circuit. The current mirror circuit includes a reference branch circuit and at least one mirror branch circuit. The reference branch circuit generates a reference current according to a base current, and the at least one mirror branch circuit generates at least one mirrored current according to the reference current. The operational amplifier receives a first voltage from the reference branch circuit and a second voltage from the at least one mirror branch circuit, and adjusts the first voltage by generating a control voltage according to the second voltage. The bias generating circuit is coupled to the at least one mirror branch circuit and generates a bias signal according to the at least one mirrored current.

Abstract: A switch device includes a first radio-frequency (RF) terminal, a second RF terminal, a first transistor, a second transistor, and a variable resistance element. The first transistor includes a first terminal coupled to the first RF terminal, a second terminal, and a control terminal coupled to a control signal terminal providing a control signal. The second transistor includes a first terminal coupled to the second terminal of the first transistor, a second terminal coupled to the second RF terminal, and a control terminal. The variable resistance element is coupled between the second terminal of the first transistor and a bias voltage terminal. When the first transistor and the second transistor are in a transient state, the variable resistance element provides a lower resistance. When the first transistor and the second transistor are in an ON state, the variable resistance element provides a higher resistance.

Abstract: A radio-frequency circuit can include a power amplifier, a first bias circuit and a second bias circuit. The power amplifier can include an input terminal used to receive a radio-frequency signal, and an output terminal used to output an amplified radio-frequency signal. The first bias circuit can include a first output terminal coupled to the input terminal of the power amplifier through a common node. The second bias circuit can include a second output terminal and a current adjustment circuit, where the second output terminal can be coupled to the common node, and the current adjustment circuit can include a transistor. The transistor can include a first terminal coupled to the second output terminal, a second terminal used to receive a reference voltage, and a control terminal.

Abstract: A switch device includes a driver circuit, a switch circuit and a level transition circuit. The driver circuit includes an input terminal for receiving an input signal, an output terminal for outputting an output signal, a first terminal coupled to a first reference terminal, and a second terminal coupled to a second reference terminal. The switch circuit includes a control terminal for receiving the output signal. The level transition circuit includes a first terminal for receiving the output signal, a second terminal coupled to a third reference terminal, and a third terminal for receiving the input signal. In a transition interval, the input signal is transitioned from a first input signal level to a second input signal level, the level transition circuit transitions the output signal from a first output signal level to a third output signal level between the first output signal level and a second output signal level.

Abstract: A voltage state detector includes a voltage drop circuit, a pull-down circuit, a load circuit, a transistor, a pull-up circuit, first and second output terminals, and a logic circuit. The pull-down circuit is coupled to the voltage drop circuit. The transistor has a first terminal coupled to the load circuit, a second terminal coupled to the pull-down circuit, and a control terminal coupled to the voltage drop circuit. The pull-up circuit is coupled to the load circuit and the voltage drop circuit. The first output terminal is coupled to the first terminal of the transistor for outputting a first state determination signal. The second output terminal is coupled to the voltage drop circuit for outputting a second state determination signal. The logic circuit includes a NOR gate for performing an NOR operation on the first state determination signal and the second state determination signal to output a control signal.

Abstract: A switch device includes a first radio-frequency (RF) terminal, a second RF terminal, a first transistor, a second transistor, and a variable resistance element. The first transistor includes a first terminal coupled to the first RF terminal, a second terminal, and a control terminal coupled to a control signal terminal providing a control signal. The second transistor includes a first terminal coupled to the second terminal of the first transistor, a second terminal coupled to the second RF terminal, and a control terminal. The variable resistance element is coupled between the second terminal of the first transistor and a bias voltage terminal. When the first transistor and the second transistor are in a transient state, the variable resistance element provides a lower resistance. When the first transistor and the second transistor are in an ON state, the variable resistance element provides a higher resistance.

Abstract: A compensation circuit includes a resistor-capacitor circuit and a control circuit. The resistor-capacitor circuit is used to generate a first voltage when a reference signal is in a first state, and generate a second voltage and a third voltage when the reference signal is in a second state. The resistor-capacitor circuit includes a first resistor-capacitor sub-circuit and a second resistor-capacitor sub-circuit. The first resistor-capacitor sub-circuit and the second resistor-capacitor sub-circuit are coupled to the control circuit, and operate simultaneously to compute an ON time of a front end module. The control circuit is coupled to the resistor-capacitor circuit, and is used to acquire the ON time according to the first voltage, the second voltage, and the third voltage, and includes an adjustment circuit used to generate a bias signal according to the ON time, and output the bias signal to the front end module.

Abstract: The present invention discloses a bias compensation circuit. The bias compensation circuit includes a detecting circuit, including a diode-connected transistor circuit, with a first end for receiving a first current, and a second end coupled to a first reference voltage end; and a first diode circuit, with a first end for receiving a second current, and a second end coupled to the first reference voltage end; wherein the detecting circuit provides a first voltage level according to the diode-connected transistor circuit, and provides a second voltage level according to the first diode circuit; a voltage-current converting circuit, coupled to the detecting circuit, for generating a first reference current according to the first voltage level and the second voltage level; and a bias circuit, coupled to the voltage-current converting circuit, for receiving the first reference current, to provide a bias voltage level according to the first reference current.

Abstract: A switch device includes a first radio-frequency (RF) terminal, a second RF terminal, a first transistor, a second transistor, and a variable resistance element. The first transistor includes a first terminal coupled to the first RF terminal, a second terminal, and a control terminal coupled to a control signal terminal providing a control signal. The second transistor includes a first terminal coupled to the second terminal of the first transistor, a second terminal coupled to the second RF terminal, and a control terminal. The variable resistance element is coupled between the second terminal of the first transistor and a bias voltage terminal. When the first transistor and the second transistor are in a transient state, the variable resistance element provides a lower resistance. When the first transistor and the second transistor are in an ON state, the variable resistance element provides a higher resistance.

Abstract: A device of measuring a duty cycle includes a resistor-capacitor circuit and a control circuit. The resistor-capacitor circuit is used to generate a first voltage when a reference signal is in a first state, and generate a second voltage and a third voltage when the reference signal is in a second state. The control circuit is coupled to the resistor-capacitor circuit, and configured to acquire an ON-time according to the first voltage, the second voltage and the third voltage. The ON-time is a time interval during which the reference signal is in the first state.

Abstract: A voltage state detector includes a voltage drop circuit, a pull-down circuit, a load circuit, a transistor, a pull-up circuit, first and second output terminals, and a logic circuit. The pull-down circuit is coupled to the voltage drop circuit. The transistor has a first terminal coupled to the load circuit, a second terminal coupled to the pull-down circuit, and a control terminal coupled to the voltage drop circuit. The pull-up circuit is coupled to the load circuit and the voltage drop circuit. The first output terminal is coupled to the first terminal of the transistor for outputting a first state determination signal. The second output terminal is coupled to the voltage drop circuit for outputting a second state determination signal. The logic circuit includes a NOR gate for performing an NOR operation on the first state determination signal and the second state determination signal to output a control signal.

Abstract: A switch device includes a first radio-frequency (RF) terminal, a second RF terminal, a first transistor, a second transistor, and a variable resistance element. The first transistor includes a first terminal coupled to the first RF terminal, a second terminal, and a control terminal coupled to a control signal terminal providing a control signal. The second transistor includes a first terminal coupled to the second terminal of the first transistor, a second terminal coupled to the second RF terminal, and a control terminal. The variable resistance element is coupled between the second terminal of the first transistor and a bias voltage terminal. When the first transistor and the second transistor are in a transient state, the variable resistance element provides a lower resistance. When the first transistor and the second transistor are in an ON state, the variable resistance element provides a higher resistance.

Abstract: A voltage state detector includes an input terminal, a voltage drop circuit, a pull-down circuit, a load circuit, a transistor, a pull-up circuit, a first output terminal, and a second output terminal. The voltage drop circuit is coupled to the input terminal. The pull-down circuit is coupled to the voltage drop circuit and a first reference terminal. The load circuit is coupled to a second reference terminal. The transistor has a first terminal coupled to the load circuit, a second terminal coupled to the first reference terminal, and a control terminal coupled to the voltage drop circuit. The pull-up circuit is coupled to the second reference terminal and the voltage drop circuit. The first output terminal is coupled to the first terminal of the transistor for outputting a first state determination signal. The second output terminal is coupled to the voltage drop circuit for outputting a second state determination signal.

Abstract: A device of measuring a duty cycle includes a resistor-capacitor circuit and a control circuit. The resistor-capacitor circuit is used to generate a first voltage when a reference signal is in a first state, and generate a second voltage and a third voltage when the reference signal is in a second state. The control circuit is coupled to the resistor-capacitor circuit, and configured to acquire an ON-time according to the first voltage, the second voltage and the third voltage. The ON-time is a time interval during which the reference signal is in the first state.

Abstract: A driving circuit includes a first reference terminal, a second reference terminal, at least one input terminal, an output terminal, a first transistor, a second transistor, a switch module, and at least one control signal terminal. The at least one input terminal receives at least one input signal. The output terminal outputs an output signal in response to the at least one input signal. The first transistor and the second transistor respectively include control terminals coupled to the at least one input terminal. The switch module includes at least one control terminal coupled to the at least one control signal terminal to receive at least one control signal. The at least one input signal has a transition period. The switch module can be turned off according to the at least one control signal.

Abstract: A power amplifier includes a transistor, a temperature sensor and a filter. The transistor is used to receive a bias signal and amplify a radio frequency (RF) signal. The temperature sensor is arranged in proximity to the transistor, and is used to detect a temperature of the transistor to provide a voltage signal at a control node accordingly. The filter is coupled to the temperature sensor and is used to filter the voltage signal to generate a filtered voltage. The bias signal is adjusted according to the filtered voltage.

Abstract: A temperature detector is used to detect a temperature of a circuit under test, and includes a temperature coefficient component, a multiplier, an impedance component and a node. The temperature coefficient component is arranged in proximity to the circuit under test. A control terminal of the multiplier is coupled to a second terminal of the temperature coefficient component. The impedance component is coupled between the second terminal of the temperature coefficient component and the control terminal of the multiplier, or between a second terminal of the multiplier and a third voltage terminal. The node is formed between the second terminal of the temperature coefficient component and the control terminal of the multiplier. A voltage at the node and an amplified detection current flowing to a first terminal of the multiplier are positively correlated to the temperature of the circuit under test.

Abstract: An amplification circuit includes a switch circuit, an amplifier, and a control circuit. The switch circuit has a first terminal coupled to a radio frequency signal input terminal or a system voltage terminal, a second terminal coupled to an input terminal of the amplifier, and a control terminal configured to receive a control signal. The amplifier amplifies a radio frequency signal. The control circuit generates the control signal according to a driving current generated by the amplifier. When the control circuit determines that the amplifier operates in a high power mode, the control circuit controls the control signal to adjust a conducting level between the first terminal and the second terminal of the switch circuit according to the intensity of the driving current.