A transformer device includes a first coil, a second coil, and a third coil. The first coil includes a first ring structure, a second ring structure, a first connecting portion, and a first terminal, in which the first terminal is arranged on the first connecting portion and is located at a central location between the first ring structure and the second ring structure, the first terminal is connected to the first ring structure through the first connecting portion in a first direction, and connected to the second ring structure through the first connecting portion in a second direction, and the first direction is the opposite of the second direction. The second coil is configured to couple the first ring structure. The third coil is configured to couple the second ring structure, in which the second coil and the third coil have the same structure.

A power amplifier circuitry (100) comprises: a transistor stack (110) comprising at least two stacked transistor units (112A, 112B, 112C) for amplifying input signals; wherein each stacked transistor unit (112A, 112B, 112C) comprises a plurality of controllable segments (120-1 to 120-N, 130-1 to 130-N, 140-1 to 140-N), each comprising a segment transistor (122, 132, 142), wherein source terminals (123, 133, 143) within each transistor unit are connected, drain terminals (125, 135, 145) within each transistor unit are connected and gate terminals (124, 134, 144) within each transistor unit are connected, wherein each segment transistor (122, 132, 142) further comprises a back gate terminal (126, 136, 146) for setting a body bias, wherein at least two of the segment transistors (122, 132, 142) within each transistor unit have independently connected back gate terminals (126, 136, 146); and a control unit (190) configured to control the body bias for selecting an amplifier class of each of the controllable segments (120-1 to 120-N, 130-1 to 130-N, 140-1 to 140-N) of each of the stacked transistor units (112A, 112B, 112C).

Disclosed is an amplifier having a carrier amplifier configured as a common-emitter carrier power stage and a peaking amplifier configured as a common-emitter peaking power stage. Further included is power adaptive biasing circuitry coupled between the carrier amplifier and the peaking amplifier, wherein the power adaptive biasing circuitry is configured to sense direct current base voltages of the common-emitter carrier power stage and to generate control currents that debias the common-emitter carrier power stage in response to the current base voltages of the common-emitter carrier power stage.

A testing system includes: a dividing circuit configured to receive a testing signal and provide a plurality of input signals according to the testing signal; and a plurality of power-amplifier chips coupled to the dividing circuit, each of the plurality of power-amplifier chips being configured to be tested by receiving a respective input signal of the plurality of input signals and generating a respective output signal for a predetermined testing time.

A power amplification system includes a Power Amplifier (PA) for amplifying an input RF signal. An adaptive bias circuit is configured to adaptively set a bias of the PA. The adaptive biasing circuit includes a gain expansion circuit, a gain compression circuit and a biasing circuit. The gain expansion circuit derives a gain-expansion control signal from the input RF signal. For a first sub-range of the input RF signal, the gain-expansion control signal has a larger dynamic range than the input RF signal. The gain compression circuit derives a gain-compression control signal from the input RF signal. For a second sub-range of the input RF signal having higher power levels than the first sub-range, the gain-compression control signal has a smaller dynamic range than the input RF signal. The biasing circuit sets the bias of the PA responsively to the gain-expansion control signal and the gain-compression control signal.

An amplifier includes a first coil coupled to at least one input node. The amplifier further includes second and third coils. A first terminal of the second coil is coupled to a source terminal of a first transistor, while a second terminal of the second coil is coupled to a source terminal of a second transistor. A third coil includes first and second terminals coupled to gate terminals of the first and second transistors, respectively. Responsive to receiving an input signal, the first coil electromagnetically conveys the signal to the second and third coils.

An amplifier comprises a common emitter stage coupled to a first and a second input, a common base stage coupled to the common emitter stage and to a first and a second output, and a cancellation path coupled to the common emitter stage and the common base stage and to the first and second outputs. The cancellation path generates a first cancellation signal that is 180 degrees out of phase with a first leakage signal at the first output and a second cancellation signal that is 180 degrees out of phase with a second leakage signal at the second output. The cancellation path comprises a first cancellation transistor coupled to the common emitter stage and the common base stage and to the first output and a second cancellation transistor coupled to the common emitter stage and the common base stage and to the second output.

A power amplifier circuitry (100) comprises: a transistor stack (110) comprising at least two stacked transistor units (112A, 112B, 112C) for amplifying input signals; wherein each stacked transistor unit (112A, 112B, 112C) comprises a plurality of controllable segments (120-1 to 120-N, 130-1 to 130-N, 140-1 to 140-N), each comprising a segment transistor (122, 132, 142), wherein source terminals (123, 133, 143) within each transistor unit are connected, drain terminals (125, 135, 145) within each transistor unit are connected and gate terminals (124, 134, 144) within each transistor unit are connected, wherein each segment transistor (122, 132, 142) further comprises a back gate terminal (126, 136, 146) for setting a body bias, wherein at least two of the segment transistors (122, 132, 142) within each transistor unit have independently connected back gate terminals (126, 136, 146); and a control unit (190) configured to control the body bias for selecting an amplifier class of each of the controllable segments (120-1 to 120-N, 130-1 to 130-N, 140-1 to 140-N) of each of the stacked transistor units (112A, 112B, 112C).

An integrated circuit device is provided. In some examples, the integrated circuit device includes a first amplifier path, a second amplifier path coupled in parallel with the first amplifier path, a matching network coupled to the first amplifier path and the second amplifier path, and an antenna coupled to the matching network. In some such examples, the first amplifier path includes a first differential power amplifier coupled to the matching network, and the second amplifier path includes a second differential power amplifier coupled to the matching network. The integrated circuit device may further include a controller coupled to selectively enable the first amplifier path to provide a transmitter output power within a first range and to selectively enable the second amplifier path to provide a transmitter output power within a second range that is different from the first range.

An apparatus includes a transceiver circuit, a series capacitor, and a shunt switch. The transceiver circuit may comprise a transmit chain including an output matching network and a receive chain including an input matching network. An output of the output matching network may be connected directly to an input/output of the transceiver circuit. The series capacitor may be connected between an input of the input matching network and the output of the output matching network. The shunt switch may be connected between the input of the input matching network and a circuit ground potential of the transceiver circuit.