A power amplifier circuit includes N (N is an integer equal to or greater than 2) power amplifier circuit cores, which in operation, amplify power of an input signal, N inductors, which in operation, are connected to the N power amplifier circuit cores, and ring-oscillator-type transconductance (gm) generation circuitry, which in operation, generates transconductance (gm) for compensating power loss of the N inductors.

The disclosure generally relates to a compact bypass and decoupling structure that can be used in a millimeter-wave radio frequency integrated circuit (RFIC). For example, according to various aspects, an RFIC incorporating the compact bypass and decoupling structure may comprise a grounded substrate, a mid-metal ground plane, a bypass capacitor disposed between the grounded substrate and the mid-metal ground plane, and a decoupling inductor disposed over the mid-metal ground plane. The bypass capacitor may close a current loop in the RFIC and the decoupling inductor may provide damping in a supply network associated with the RFIC. Furthermore, the decoupling conductor may have a self-resonance substantially close to an operating band associated with the RFIC to increase series isolation, introduce substrate losses that facilitate the damping in the supply network, and prevent high-Q resonances.

A direct current (DC)-DC converter that includes a first switching converter and a multi-stage filter is disclosed. The multi-stage filter includes at least a first inductance (L) capacitance (C) filter and a second LC filter coupled in series between the first switching converter and a DC-DC converter output. The first LC filter has a first LC time constant and the second LC filter has a second LC time constant, which is less than the first LC time constant. The first LC filter includes a first capacitive element having a first self-resonant frequency, which is about equal to a first notch frequency of the multi-stage filter.

A direct current (DC)-DC converter that includes a first switching converter and a multi-stage filter is disclosed. The multi-stage filter includes at least a first inductance (L) capacitance (C) filter and a second LC filter coupled in series between the first switching converter and a DC-DC converter output. The first LC filter has a first LC time constant and the second LC filter has a second LC time constant, which is less than the first LC time constant. The first LC filter includes a first capacitive element having a first self-resonant frequency, which is about equal to a first notch frequency of the multi-stage filter.

A power amplifier (PA) cell is coupled to an input signal source, and includes a transistor coupled to the load; a first inductor coupled to a gate of the transistor; and a second inductor coupled to a source of the transistor, wherein the first inductor and the second inductor each includes a first conductive coil and a second conductive coil, respectively, having first and second inductance values, respectively, such that the PA cell includes a terminal between the gate of the transistor and the input signal source, and the terminal is impedance matched with the input signal source.

A power amplifier (PA) cell is coupled to an input signal source, and includes a transistor coupled to the load; a first inductor coupled to a gate of the transistor; and a second inductor coupled to a source of the transistor, wherein the first inductor and the second inductor each includes a first conductive coil and a second conductive coil, respectively, having first and second inductance values, respectively, such that the PA cell includes a terminal between the gate of the transistor and the input signal source, and the terminal is impedance matched with the input signal source.

An amplifier may include control circuitry that may track a first input signal parameter and, in response, adjust a value of a second input parameter. Input parameter tracking and adjustment may facilitate control of output parameters for the amplifier. For example, an envelope-tracking amplifier may track input signal amplitude and adjust other input parameters in response. The adjustments may facilitate control of output parameters, such as gain or efficiency. The amplifier may further include calibration circuitry to determine adjustment responses to various tracked input parameters.

An amplifier may include control circuitry that may track a first input signal parameter and, in response, adjust a value of a second input parameter. Input parameter tracking and adjustment may facilitate control of output parameters for the amplifier. For example, an envelope-tracking amplifier may track input signal amplitude and adjust other input parameters in response. The adjustments may facilitate control of output parameters, such as gain or efficiency. The amplifier may further include calibration circuitry to determine adjustment responses to various tracked input parameters.

An amplifier includes an input terminal for receiving an input signal, an output terminal for outputting an output signal, a first transistor, a second transistor having a first terminal coupled to a second terminal of the first transistor, a third transistor having a first terminal coupled to a second terminal of the second transistor, a capacitor coupled between a control terminal and a second terminal of the third transistor, a bias circuit coupled to the first terminal of the third transistor for providing a bias voltage to the third transistor, a fourth transistor having a first terminal coupled to the input terminal and a second terminal coupled to the output terminal for providing a bypass path, and a fifth transistor having a first terminal coupled to the first terminal of the first transistor and a second terminal coupled to the output terminal.

A power switch 307a is provided between a bias generation circuit 301 and a high potential power source, or a power switch 307b is provided between the bias generation circuit 301 and a low potential power source. A bias potential Vb output from the bias generation circuit 301 is held by a potential holding circuit 300. The bias potential Vb held by the potential holding circuit 300 is input to a bias generation circuit 301a, and a bias potential Vb2 output from the bias generation circuit 301a on which an input signal IN is superimposed is input to an amplifier circuit 302. The potential holding circuit 300 is constituted of a capacitor 306 and a switch 305 formed of, for example, a transistor with a low off-state current that is formed using a wide band gap oxide semiconductor. Structures other than the above structure are claimed.