Abstract: A switch device includes a signal input terminal and a switch circuit. The signal input terminal is used to receive a radio frequency signal. The switch circuit is coupled to the signal input terminal, and includes a first transistor and a second transistor. The first transistor includes a control terminal used to receive a first control voltage to turn off the first transistor; a first terminal; and a second terminal. The second transistor includes a control terminal used to receive a second control voltage to turn off the second transistor; a first terminal; and a second terminal. The second control voltage is different from the first control voltage.

Abstract: An amplifier device includes an amplifying unit and a bias module. The amplifying unit has a first end coupled to a voltage source configured to receive a source voltage, a second end configured to receive an input signal, and a third end coupled to a first reference potential terminal configured to receive a first reference potential. The first end of the amplifying unit is configured to output an output signal amplified by the amplifying unit. The bias module is coupled to the second end of the amplifying unit, and configured to receive a voltage signal to generate a bias current according to a first counter-gradient and a second counter-gradient, and provide the bias current to the amplifying unit. The voltage signal is a variable voltage. A supply current flowing into the amplifying unit and is adjusted in accordance with the voltage signal to stay within a predetermined range.

Abstract: A radio frequency (RF) device and a voltage generation and harmonic suppressor thereof are provided. The RF device includes the voltage generation and harmonic suppressor and a RF circuit. The voltage generation and harmonic suppressor is configured to receive a RF signal to output at least one direct current (DC) voltage related to the RF signal, and configured to suppress a harmonic generated by the RF signal in the voltage generation and harmonic suppressor. The RF circuit is configured to receive the RF signal, and configured to perform an operation according to the at least one DC voltage.

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 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: The invention provides a radio frequency (RF) amplifier apparatus including an amplifier and a resonance circuit. An input terminal of the amplifier receives an RF signal. The amplifier amplifies a first frequency component of the RF signal and outputs the amplified first frequency component to an output terminal of the amplifier. A first terminal and a second terminal of the resonance circuit are respectively coupled to the input terminal and the output terminal of the amplifier. The resonance circuit provides a low impedance path for a second frequency component of the RF signal between the input terminal and the output terminal of the amplifier, and provides a high impedance path for the first frequency component of the RF signal between the input terminal and the output terminal of the amplifier.

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.

Abstract: A radio frequency signal transmission circuit includes a direct current blocking unit, a biasing impedance circuit, and a radio frequency element. The direct current blocking unit has a first terminal for receiving an input signal, and a second terminal coupled to a first bias voltage terminal. The biasing impedance circuit has a first terminal coupled to the first bias voltage terminal for providing a first bias voltage, and a second terminal coupled to a second bias voltage terminal for receiving a second bias voltage. The radio frequency element is coupled to the first bias voltage terminal, and receives and processes the input signal. When the biasing impedance circuit operates in a first mode, the biasing impedance circuit provides a first impedance. When the biasing impedance circuit operates in a second mode, the biasing impedance circuit provides a second impedance greater than the first impedance.

Abstract: A radio frequency device and a voltage generating device thereof are provided. The voltage generating device includes a first transistor, a second transistor, and a voltage dividing circuit. A first terminal of the first transistor receives a first voltage. A first terminal of the second transistor receives a second voltage. A first connection terminal and a second connection terminal of the voltage dividing circuit are respectively coupled to second terminals of the first transistor and the second transistor. The voltage dividing circuit generates a first divided voltage and a second divided voltage. The first divided voltage is used as an output voltage of the voltage generating device. The second divided voltage is output as a control voltage to a control terminal of the first transistor and a control terminal of the second transistor.

Abstract: A radio frequency apparatus and a voltage generating device thereof are provided. The voltage generating device includes a first switch and a second switch. A first terminal of the first switch receives a first voltage. A control terminal of the first switch receives a second voltage. A first terminal of the second switch receives the second voltage. A control terminal of the second switch receives the first voltage. A second terminal of the second switch and a second terminal of the first switch are coupled to an output node, wherein the output node outputs an output voltage related to at least one of the first voltage and the second voltage.

Abstract: An amplification device includes an amplification circuit, an inductor, a regulator, and a impedance circuit. The amplification circuit has an input terminal for receiving a radio frequency signal, and an output terminal for outputting an amplified radio frequency signal. The inductor has a first terminal, and a second terminal coupled to the output terminal of the amplification circuit. The regulator is coupled to the first terminal of the inductor and generates a steady voltage and/or a steady current. The impedance circuit has a first terminal coupled to the output terminal of the amplification circuit, and a second terminal coupled to a first system voltage terminal. The impedance circuit provides a low frequency impedance path to suppress a beat frequency signal in the amplified radio frequency signal.

Abstract: A matching circuit includes an input terminal, an output terminal, a first impedance component, a first set of switching devices, a second impedance component, a second set of switching devices and a controller. The first impedance component includes a first terminal coupled between the input terminal and the output terminal, and a second terminal. The first set of switching devices is coupled to the second terminal of the first impedance component, the controller and a reference terminal. The second impedance component includes a first terminal coupled between the second terminal of the first impedance component and the first set of switching devices, and a second terminal. The second set of switching devices is coupled to the second terminal of the second impedance component, the controller and the reference terminal. The controller controls the first set of switch devices and the second set of switch devices according to a detection signal.

Abstract: A switching circuit includes a first transmission terminal, a second transmission terminal, a third transmission terminal, and a variable impedance circuit. The first and the second transmission terminals coupled to a common node form a first transmission path. The third transmission terminal coupled to the common node forms a second transmission path with the first transmission terminal. The variable impedance circuit has a first terminal coupled between the common node and the third transmission terminal, and a second terminal coupled to a first reference potential terminal. When the first transmission path transmits a first signal, a first frequency bandwidth range provided by the variable impedance circuit is determined according to a first frequency of the first signal so that the variable impedance circuit provides low impedance in the first frequency bandwidth range, and the first frequency bandwidth range covers the first frequency.

Abstract: A voltage controlled circuit includes a tracking circuit, an operational amplifier, a transistor, a feedback circuit and a sample and hold circuit. The tracking circuit generates an updated enabling voltage according to an enabling voltage, a sample enabling voltage and a sample reference voltage. The operational amplifier includes a first input terminal used to receive an input voltage, a second input terminal used to receive a feedback voltage, and an output terminal used to output a control voltage. The transistor includes a control terminal used to receive the control voltage, a first terminal used to receive a reference voltage, and a second terminal used to output a regulated voltage. The feedback circuit generates the feedback voltage according to the regulated voltage. The sample and hold circuit is used to sample the input voltage to generate the sample enabling voltage, and sample the feedback voltage to generate the sample reference voltage.

Abstract: A switching circuit includes a first transmission terminal, a second transmission terminal, a third transmission terminal, and a variable impedance circuit. The first and the second transmission terminals coupled to a common node form a first transmission path. The third transmission terminal coupled to the common node forms a second transmission path with the first transmission terminal. The variable impedance circuit has a first terminal coupled between the common node and the third transmission terminal, and a second terminal coupled to a first reference potential terminal. When the first transmission path transmits a first signal, a first frequency bandwidth range provided by the variable impedance circuit is determined according to a first frequency of the first signal so that the variable impedance circuit provides low impedance in the first frequency bandwidth range, and the first frequency bandwidth range covers the first frequency.

Abstract: An amplifier circuit includes an input terminal used to receive an input signal, an output terminal used to output an output signal, an amplification unit, and a phase adjustment unit. The amplification unit includes an input terminal coupled to the input terminal of the amplifier circuit, an output terminal coupled to the output terminal of the amplifier circuit, a first terminal coupled to a first voltage terminal, and a second terminal coupled to a second voltage terminal. The phase adjustment unit is coupled to the amplification unit. When the amplifier circuit is operated in a first mode, the output signal has a first phase, and when the amplifier circuit is operated in a second mode, the output signal has a second phase. A difference between the first phase and the second phase is within a predetermined range.

Abstract: An amplifier circuit includes a first amplifier and a second amplifier. The first amplifier receives a first signal and generates a first amplification signal accordingly. The second amplifier receives a second signal and generates a second amplification signal accordingly. The first signal is related to a first frequency band, and the second signal is related to a second frequency band different from the first frequency band. When one of the first amplifier and the second amplifier is in use, the other one of the first amplifier and the second amplifier is unused. The first amplifier and second amplifier are coupled to a reference voltage terminal through a common node. The first amplifier includes a switch coupled between the common node and a stage of the first amplifier, and the switch can be controlled for reducing the loading effect caused by the first amplifier on the second amplifier.

Abstract: A signal switching apparatus includes a signal control switch, a switch circuit, a blocking capacitor and a surge current dissipating circuit. The signal control switch coupled between a first signal transceiving end and a second signal transceiving end is turned on or turned off according to a first control signal. The switch circuit having at least one first transistor is controlled by a second control signal to be turned on or off, and a first end of the switch circuit is coupled to the first signal transceiving end. The blocking capacitor is coupled between a second end of the switch circuit and a reference voltage terminal. The surge current dissipating circuit having at least one second transistor is coupled between the second end of the switch circuit and the reference voltage terminal. The second transistor is configured to dissipate a surge current and also turned off when operated normally.

Abstract: An amplification circuit includes an input terminal, an output terminal, a capacitor, a bias unit, an amplification unit, and an impedance unit. The input terminal receives a radio frequency signal. The capacitor is coupled to the input terminal and the bias unit. The bias unit includes a transistor for controlling the bias current. The transistor has a first terminal for receiving a system voltage, and a control terminal coupled to the reference voltage terminal. The amplification unit has an input terminal coupled to the capacitor and the bias unit, and an output terminal coupled to the output terminal of the amplification circuit. The impedance unit has a first terminal coupled to the bias unit, and a second terminal coupled to the input terminal of the amplification circuit and the capacitor. The impedance unit adjusts the amplifying linearity of the amplification circuit according to a selection signal.

Abstract: An amplifier circuit includes an output terminal, an amplification unit and a switch. The output terminal is used to output an amplification signal. The amplification unit includes a first transistor and a second transistor. The first transistor includes a control terminal for receiving a first input signal, a first terminal coupled to the output terminal for outputting an amplified first input signal, and a second terminal. The second transistor includes a control terminal for receiving a second input signal, a first terminal coupled to the output terminal for outputting an amplified second input signal, and a second terminal. The switch includes a first terminal coupled to the second terminal of the first transistor, and a second terminal. The amplification signal is generated using at least the amplified first input signal and/or the amplified second input signal.