An inductor-less low noise amplifier (LNA) with high linearity is disclosed. The low noise amplifier includes: an input signal stage receiving an input signal; a first amplifier configured to receive the input signal, generate a first amplification signal by amplifying the received input signal, and output the generated first amplification signal, as a first output signal, to a first output terminal; a second amplifier configured to receive the input signal, generate a second amplification signal by amplifying the received input signal, and output the generated second amplification signal, as a second output signal, to a second output terminal; an output signal stage outputting a superimposition signal obtained by superimposing the first output signal and the second output signal; a first resistor feeding back the superimposition signal to the input signal stage; and a switch connecting/disconnecting between the input signal stage and the output signal stage.

An amplifier circuit including a substrate layer and a plurality of lateral bipolar junction transistors positioned entirely above the substrate. The lateral bipolar junction transistors include a plurality of monolithic emitter-collector regions coplanar to each other. Each of the emitter-collector regions is both an emitter region of a first bipolar junction transistor a collector region of a second bipolar junction transistor from the lateral bipolar junction transistors. Accordingly, the lateral bipolar junction transistors are electrically coupled in series circuit at the emitter-collector regions.

This disclosure relates to the field of amplifiers for multi-level optical communication and more particularly to techniques for trans-impedance amplifiers (TIA) with gain control. The claimed embodiments address the problem of implementing a low cost TIA that exhibits high linearity, low noise, low power, and wide bandwidth. More specifically, some claims are directed to approaches for providing TIA gain control using a plurality of inverter-based replica gain control cells controlled by a feedback loop to manage the current into the amplifying output stage and thereby the TIA output voltage.

Disclosed is a power amplifier having an output stage (12) having a radio frequency (RF) output (14) and an RF input (16) and a driver stage (18) having a driver input (20) coupled to the RF input (16), a control input (22), and a driver output (24), wherein the driver stage (18) is configured to have a controllable soft compression characteristic that substantially neutralizes a gain expansion characteristic of the output stage (12). Also included is a controller (26) having a control output (28) coupled to the control input (22) of the driver stage (18), wherein the controller (26) is configured to generate a control signal at the control output (28) that controls the soft compression characteristic of the driver stage (18).

Disclosed is a cascode configuration that moves the gate of the cascode substantially without delay relative to an output node by capacitively coupling the latter onto the cascode gates. The passive coupling eliminates the need for actively driving the gates of the cascode. In some embodiments, the only circuitry needed on the cascode gate may be a biasing circuit that limits the swing on the cascode gate between V.sub.max and 2V.sub.max, where V.sub.max is a transistor device rating.

This disclosure relates to the field of amplifiers for multi-level optical communication and more particularly to techniques for trans-impedance amplifiers (TIA) with gain control. The claimed embodiments address the problem of implementing a low cost TIA that exhibits high linearity, low noise, low power, and wide bandwidth. More specifically, some claims are directed to approaches for providing TIA gain control using a plurality of inverter-based replica gain control cells controlled by a feedback loop to manage the current into the amplifying output stage and thereby the TIA output voltage.

A power amplifier using multi-path common-mode feedback loops for radio frequency linearization is disclosed. In one aspect, a complementary metal oxide semiconductor (CMOS) power amplifier containing cascoded n-type field effect transistors (NFETs) and cascoded p-type FETs (PFETs) may have a common-mode feedback network and provides bias voltages that are dynamically varying with the signal power to keep the output common-mode fixed around a half-supply level, while the small-signal and large-signal transconductances of the FET's are kept balanced. A further feedback network may be associated with the supply voltage to assist in providing a symmetrical supply signal. The symmetrical supply signal allows for supply variations without introducing distortion for the power amplifier stage.

A power amplifier using multi-path common-mode feedback loops for radio frequency linearization is disclosed. In one aspect, a complementary metal oxide semiconductor (CMOS) power amplifier containing cascoded n-type field effect transistors (NFETs) and cascoded p-type FETs (PFETs) may have a common-mode feedback network and provides bias voltages that are dynamically varying with the signal power to keep the output common-mode fixed around a half-supply level, while the small-signal and large-signal transconductances of the FETs are kept balanced. A further feedback network may be associated with the supply voltage to assist in providing a symmetrical supply signal. The symmetrical supply signal allows for supply variations without introducing distortion for the power amplifier stage.