Diversity receiver front end system with amplifier phase compensation. A receiving system can include a first amplifier disposed along a first path, corresponding to a first frequency band, between an input of the receiving system and an output of the receiving system. The receiving system can include a second amplifier disposed along a second path, corresponding to a second frequency band, between the input of the receiving system and the output of the receiving system. The receiving system can include a first phase-shift component disposed along the first path and configured to phase-shift the second frequency band of a signal passing through the first phase-shift component based on a phase-shift caused by the first amplifier at the second frequency band.

Embodiments of a Doherty amplifier device are provided, including a first amplifier stage having a first gain; a second amplifier stage having a second gain that is less than the first gain; and an input power splitter coupled to inputs of the first and second amplifier stages, wherein the input power splitter includes either an inductive element, a capacitive element, or both coupled between the inputs of the first and second amplifier stages, and a resistive element coupled to the input of the second amplifier stage, the input power splitter respectively delivers first and second power levels to inputs of the first and second amplifier stages, and the resistive element is configured to tune gain linearity of the Doherty amplifier device by increasing the second power level to be greater than the first power level, based on a ratio of the second gain to the first gain.

A semiconductor device that functions as a relay station and is reduced in size is provided. The semiconductor device includes an operational amplifier, a first transistor and a first capacitor that are electrically connected to a first input side of the operational amplifier, and a first resistor and a second resistor that are electrically connected to a second input side. The second resistor is electrically connected to an output side of the operational amplifier, a gate of the first transistor is electrically connected to a first power supply, the first resistor is electrically connected to a second power supply, and at least a transistor included in the operational amplifier has a region overlapping with the first transistor.

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.

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 high-frequency module (1) includes a first substrate (101), a second substrate (102) that faces the first substrate (101), a support (103) that supports the first substrate (101) and the second substrate (102), and a plurality of high-frequency circuit components arranged in internal space formed by the first substrate (101), the second substrate (102), and the support and on both of facing principal faces of the first substrate (101) and the second substrate (102), and the plurality of high-frequency circuit components include a power amplifier element that constitutes a power amplifier circuit (16).

In a semiconductor device, received signals of different frequency bands are input selectively to low noise amplifiers. A plurality of primary inductors are coupled between differential output nodes of the respective low noise amplifiers. A secondary inductor is provided commonly for the primary inductors, and magnetically coupled to the primary inductors. A demodulator converts a received signal transmitted from one of the primary inductors to the secondary inductor by electromagnetic induction, into a signal of a low frequency.

The present invention discloses an audio processing circuit, wherein when the audio processing circuit determines that a signal being processed is a small signal, an output stage uses a regulated supply voltage provided by a voltage regulator, and the output stage uses an open-loop structure to reduce noise of an output audio signal; and when the audio processing circuit determines that the signal being processed is a large signal, the output stage directly uses the supply voltage without using the regulated supply voltage, and the output stage uses a closed-loop structure to reduce the total harmonic distortion of the output audio signal. By using the present invention, the audio processing circuit can have a good performance indicator with a small chip area design.

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.

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.