Abstract: A frequency-dependent resistor and circuitry employing the same are provided. In some embodiments, a resistor includes a substrate, an input port, an output port, and a conductive trace on the substrate between the input port and the output port. A resistance between the input port and the output port for a low frequency signal is at least five times lower than the resistance between the input port and the output port for an RF signal and the ratio of the frequencies of the RF signal to the low frequency signal is at least fifty. Circuitry including a transistor adapted to selectively couple the input to the output in response to a control signal provided via a resistor with resistance for a low frequency signal at least five times lower than resistance for an RF signal will have a reduced switching time while still isolating the RF signal.

Abstract: A frequency-dependent resistor and circuitry employing the same are provided. In some embodiments, a resistor includes a substrate, an input port, an output port, and a conductive trace on the substrate between the input port and the output port. A resistance between the input port and the output port for a low frequency signal is at least five times lower than the resistance between the input port and the output port for an RF signal and the ratio of the frequencies of the RF signal to the low frequency signal is at least fifty. Circuitry including a transistor adapted to selectively couple the input to the output in response to a control signal provided via a resistor with resistance for a low frequency signal at least five times lower than resistance for an RF signal will have a reduced switching time while still isolating the RF signal.

Abstract: Various embodiments provide a bias circuit for a radio frequency (RF) power amplifier (PA) to provide a direct current (DC) bias voltage, with bias boosting, to the RF PA. The bias circuit may include a bias transistor that forms a current mirror with an amplifier transistor of the RF PA. The bias circuit may further include a first resistor coupled between the gate terminal and the drain terminal of the bias transistor to block RF signals from the gate terminal of the bias transistor. The bias circuit may further include a second resistor coupled between the drain terminal of the bias transistor and the RF PA (e.g., the gate terminal of the amplifier transistor). An amount of bias boosting of the DC bias voltage provided by the bias circuit may be based on an impedance value of the second resistor.

Abstract: Various embodiments provide a bias circuit for a radio frequency (RF) power amplifier (PA) to provide a direct current (DC) bias voltage, with bias boosting, to the RF PA. The bias circuit may include a bias transistor that forms a current mirror with an amplifier transistor of the RF PA. The bias circuit may further include a first resistor coupled between the gate terminal and the drain terminal of the bias transistor to block RF signals from the gate terminal of the bias transistor. The bias circuit may further include a second resistor coupled between the drain terminal of the bias transistor and the RF PA (e.g., the gate terminal of the amplifier transistor). An amount of bias boosting of the DC bias voltage provided by the bias circuit may be based on an impedance value of the second resistor.

Abstract: A method and apparatus for biasing an amplifying device whereby the bias current tracks the input power or the power level of a control signal to thereby efficiently match the bias current with needs of the amplifying device. This method and apparatus overcomes the drawbacks of the prior art by biasing, not for maximum output power, but for the power level of the input signal or the control signal. In one embodiment a current conditioner operates in connection with the self adjusting biasing circuit to scale or adjust, potentially on an exponential basis, the biasing current for one or more amplifier stages. A cancellation current source may be configured within the bias circuit to cancel unneeded current to further minimize current consumption.

Abstract: A method and apparatus for biasing an amplifying device whereby the bias current tracks the input power or the power level of a control signal to thereby efficiently match the bias current with needs of the amplifying device. This method and apparatus overcomes the drawbacks of the prior art by biasing, not for maximum output power, but for the power level of the input signal or the control signal. In one embodiment a current conditioner operates in connection with the self adjusting biasing circuit to scale or adjust, potentially on an exponential basis, the biasing current for one or more amplifier stages. A cancellation current source may be configured within the bias circuit to cancel unneeded current to further minimize current consumption.

Abstract: A power amplifier circuit includes an amplifying transistor and a dc bias circuit for biasing the amplifier transistor to obtain a conduction angle of at least about 180°. The dc bias circuit includes a self-bias boosting circuit for initially decreasing and then increasing the dc bias voltage provided to a control terminal of the amplifying transistor by the dc bias circuit as the input signal provided to the power amplifier increases. The self-bias boosting circuit is extremely simple and compact in design, and permits the power amplifier circuits to operate in Class B or Class AB with improved power output characteristics.

Abstract: A power amplifier circuit includes an amplifying transistor and a dc bias circuit for biasing the amplifier transistor to obtain a conduction angle of at least about 180°. The dc bias circuit includes a self-bias boosting circuit for initially decreasing and then increasing the dc bias voltage provided to a control terminal of the amplifying transistor by the dc bias circuit as the input signal provided to the power amplifier increases. The self-bias boosting circuit is extremely simple and compact in design, and permits the power amplifier circuits to operate in Class B or Class AB with improved power output characteristics.