Circuits, devices and methods related to amplification with active gain bypass. In some embodiments, an amplifier can include a first amplification path implemented to amplify a signal, and having a cascode arrangement of a first input transistor and a cascode transistor to provide a first gain for the signal when in a first mode. The amplifier can further include a second amplification path implemented to provide a second gain for the signal while bypassing at least a portion of the first amplification path when in a second mode. The second amplification path can include a cascode arrangement of a second input transistor and the cascode transistor shared with the first amplification path. The amplifier can further include a switch configured to allow routing of the signal through the first amplification path in the first mode or the second amplification path in the second mode.

An amplifier includes a semiconductor substrate. A first conductive feature partially covers the bottom substrate surface to define a conductor-less region of the bottom substrate surface. A first current conducting terminal of a transistor is electrically coupled to the first conductive feature. Second and third conductive features may be coupled to other regions of the bottom substrate surface. A first filter circuit includes an inductor formed over a portion of the top substrate surface that is directly opposite the conductor-less region. The first filter circuit may be electrically coupled between a second current conducting terminal of the transistor and the second conductive feature. A second filter circuit may be electrically coupled between a control terminal of the transistor and the third conductive feature. Conductive leads may be coupled to the second and third conductive features, or the second and third conductive features may be coupled to a printed circuit board.

Diversity receiver front end system with methods for improving signal processing using tunable matching circuits. The methods can include tuning impedance matching circuits based on frequency bands. For a first path, an impedance can be provided that reduces an in-band noise figure, increases an in-band gain, decreases an out-of-band noise figure, and/or decreases an out-of-band gain. In this way, signals propagated along selectively activated paths between an input of a receiving system and an output of the receiving system can be improved. The signals can be amplified using amplifiers disposed on corresponding paths between the input and output of the receiving system.

Embodiments of the present invention provide a power amplifier, a radio remote unit RRU, and a base station. A multiphase pulse width modulator performs modulation to generate N multiphase pulse-width modulation PWM signals. The multiphase pulse-width modulation PWMn signal may be amplified. The multiphase pulse-width modulation PWMn signal may be filtered and a combination may be performed at a drain or a collector of a power amplifier transistor. According to the new radio frequency amplifier in accordance with the disclosure, envelope feeding loop inductance can be effectively reduced, so that video bandwidth is increased and DPD correction performance is improved.

In some embodiments, a filtering technique can include a pre-amplifier filter configured to filter a signal, and an amplifier assembly configured to amplify the filtered signal. The filtering technique can further include a filter circuit configured to provide selective filtering of the amplified signal based at least in part on a rejection level of the pre-amplifier filter and a gain of the amplifier assembly.

Radio-frequency (RF) amplifier having active gain bypass circuit. In some embodiments, an amplifier can include a first amplification path implemented to amplify a signal, and having a cascode arrangement of a first input transistor and a cascode transistor to provide a first gain for the signal when in a first mode. The amplifier can further include a second amplification path implemented to provide a second gain for the signal while bypassing at least a portion of the first amplification path when in a second mode. The second amplification path can include a cascode arrangement of a second input transistor and the cascode transistor shared with the first amplification path. The amplifier can further include a switch configured to allow routing of the signal through the first amplification path in the first mode or the second amplification path in the second mode.

A surface acoustic wave (SAW) filter that receives an aggregate circuit and outputs two or more sub-signals on outputs each of a different frequency band. The sub-signals are amplified by low noise amplifiers and, in one implementation, the amplified sub-signals can be summed. The outputs are connected via a switched passive network so that portions of the sub-signals on the outputs that are not in the selected frequency band are at least partially terminated.

A power amplifier circuit amplifies a radio-frequency signal in a transmit frequency band. The power amplifier circuit includes an amplifier, a bias circuit, and an impedance circuit. The amplifier amplifies power of a radio-frequency signal and outputs an amplified signal. The impedance circuit is connected between a signal input terminal of the amplifier and a bias-current output terminal of the bias circuit and has frequency characteristics in which attenuation is obtained in the transmit frequency band. The impedance circuit includes first and second impedance circuits. The first impedance circuit is connected to the signal input terminal. The second impedance circuit is connected between the first impedance circuit and the bias-current output terminal.

Diversity receiver front end system with methods for improving signal processing using tunable matching circuits. The methods can include tuning impedance matching circuits based on frequency bands. For a first path, an impedance can be provided that reduces an in-band noise figure, increases an in-band gain, decreases an out-of-band noise figure, and/or decreases an out-of-band gain. In this way, signals propagated along selectively activated paths between an input of a receiving system and an output of the receiving system can be improved. The signals can be amplified using amplifiers disposed on corresponding paths between the input and output of the receiving system.

This application provides a receiving module, a packaging structure, a printed circuit board, and an electronic device, which can mitigate a problem that application scenarios of a front-end receiving module of an existing GNSS receiver are limited. The receiving module includes a first filtering unit, an amplifying unit, and a control element. When the amplifying unit operates in a first mode, the first end of the amplifying unit acts as a signal input end, and in this way, the first filtering unit acts as a front filtering unit. When the amplifying unit operates in a second mode, the first end of the amplifying unit acts as a signal output end, and in this way, the first filtering unit acts as a rear filtering unit.