A linear amplifier outputs differential signals corresponding to differential signals input to a first signal input terminal and a second signal input terminal, and includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor, a second capacitor, a third transistor, a fourth transistor, a differential amplifier, and a signal processing circuit. The signal processing circuit includes a first transistor and a second transistor, and includes a resistor as a common voltage output part that outputs a common voltage. The differential amplifier receives the common voltage and a reference voltage, and applies a voltage corresponding to the voltage difference between the common voltage and the reference voltage to the control terminals of the transistors.

The application describes a transimpedance amplifier circuit having a first circuit branch extending between first and second supply nodes. An input NMOS transistor is located in the first circuit branch, with its drain terminal coupled to the first supply node via a load resistor, its source terminal coupled to the second supply node and its gate terminal coupled to an input node for receiving an input signal. The circuit includes a PMOS transistor having its source terminal coupled to a third supply node, its drain terminal coupled to the first circuit branch, at a node in a part of the first circuit branch extending from the drain terminal of the input transistor to the load resistor, and its gate terminal coupled to the input node. A drain current of the PMOS transistor contributes a proportion but not all of a drain current for input NMOS transistor.

A circuit for generating a radio frequency signal is provided. The circuit includes an amplifier configured to generate a radio frequency signal based on a baseband signal. Further, the circuit includes a power supply configured to generate a variable supply voltage based on a control signal indicating a desired supply voltage, and to supply the variable supply voltage to the amplifier. The circuit further includes an envelope tracking circuit configured to generate the control signal based on a bandwidth of the baseband signal, and to supply the control signal to the power supply.

A common-gate amplifying arrangement. The common-gate amplifying arrangement includes a common-gate amplifier and an inner regulated cascode. The inner regulated cascode amplifies a signal provided by the common-gate amplifier, which is responsive to an input signal.

A wideband power amplifier (PA) linearization technique is proposed. A current interpolation technique is proposed to linearize power amplifiers over a wide bandwidth. The wideband power amplifier linearization technique employs a novel transconductance Gm linearizer using a current interpolation technique that achieves improvement in the third order intermodulation over wide bandwidth for a sub-micron CMOS differential power amplifier. By using a small amount of compensating bias into an opposite phase differential pair, linearization over wide bandwidth is achieved and can be optimized by adjusting the compensating bias.

An ultra-wideband power amplifier includes a preamplifier circuit and a post amplifier circuit. The preamplifier circuit includes a first DC blocking capacitor C.sub.1, a first decoupling capacitor C.sub.2, a second decoupling capacitor C.sub.3, a stabilizing resistor R.sub.in, a first AC blocking resistor RG.sub.1, a first input inductor L.sub.1, a second input inductor L.sub.2, an output inductor L.sub.3, a first input microstrip line MLIN.sub.1, a second input microstrip line MLIN.sub.2, an output microstrip line MLIN.sub.3, and a first transistor Q.sub.1. A first end of the first DC blocking capacitor C.sub.1 acts as an input terminal of the preamplifier circuit, and a second end of the first DC blocking capacitor C.sub.1 is connected to the stabilizing resistor R.sub.in, the first input inductor L.sub.1, the first input microstrip line MLIN.sub.1, and a gate electrode of the first transistor Q.sub.1 sequentially. One end of the first decoupling capacitor C.sub.2 is grounded.

A circuit for generating a radio frequency signal is provided. The circuit includes an amplifier configured to generate a radio frequency signal based on a baseband signal. Further, the circuit includes a power supply configured to generate a variable supply voltage based on a control signal indicating a desired supply voltage, and to supply the variable supply voltage to the amplifier. The circuit further includes an envelope tracking circuit configured to generate the control signal based on a bandwidth of the baseband signal, and to supply the control signal to the power supply.

An amplifier circuit comprises a variable degeneration circuit connected to emitter terminals of transistors, and a variable negative capacitance circuit connected to differential output signal terminals. The variable degeneration circuit includes a variable capacitor and a resistor. The variable negative capacitance circuit, which is a variable current source, includes a transistor, a capacitor, and a variable current source. The variable negative capacitance circuit includes transistors, a capacitor, and variable current sources.

A high-speed transimpedance amplifier with bandwidth extension feature over full temperature range and bandwidth extension method belong to the field of integrated circuit. The present invention solves the problem existed in boosting core amplifier bandwidth technology over full temperature range. The present invention includes a preamplifier TIA, a phase splitting stage PS, a pre-driver stage Pre-Drive, an output buffer BUFF and an offset cancelation circuit OC. The preamplifier TIA adopts the gate-drain voltage cancelation technology to expand the bandwidth, so that its −3 dB bandwidth is greater than twice the closed-loop bandwidth of the first-order TIA. The pre-driver stage Pre-Drive is used to drive the output buffer BUFF. By adjusting the source-level negative feedback capacitance value of the pre-driver stage Pre-Drive circuit to generate a high-frequency gain that varies with temperature, the preamplifier TIA bandwidth differences under different temperature conditions are compensated.

A high-speed transimpedance amplifier with bandwidth extension feature over full temperature range and bandwidth extension method belong to the field of integrated circuit. The present invention solves the problem existed in boosting core amplifier bandwidth technology over full temperature range. The present invention includes a preamplifier TIA, a phase splitting stage PS, a pre-driver stage Pre-Drive, an output buffer BUFF and an offset cancelation circuit OC. The preamplifier TIA adopts the gate-drain voltage cancelation technology to expand the bandwidth, so that its −3 dB bandwidth is greater than twice the closed-loop bandwidth of the first-order TIA. The pre-driver stage Pre-Drive is used to drive the output buffer BUFF. By adjusting the source-level negative feedback capacitance value of the pre-driver stage Pre-Drive circuit to generate a high-frequency gain that varies with temperature, the preamplifier TIA bandwidth differences under different temperature conditions are compensated.