A multiple-stage amplifier includes a driver stage die and a final stage die. The driver stage die includes a first type of semiconductor substrate (e.g., a silicon substrate), a first transistor, and an integrated portion of an interstage impedance matching circuit. A control terminal of the first transistor is electrically coupled to an RF signal input terminal of the driver stage die, and the integrated portion of the interstage impedance matching circuit is electrically coupled between a current-carrying terminal of the first transistor and an RF signal output terminal of the driver stage die. The second die includes a III-V semiconductor substrate (e.g., a GaN substrate) and a second transistor. A connection, which is a non-integrated portion of the interstage impedance matching circuit, is electrically coupled between the RF signal output terminal of the driver stage die and an RF signal input terminal of the final stage die.

The present disclosure provides a power amplifier circuit capable of suppressing the occurrence of noises while enabling control of an output power level. The power amplifier circuit includes a first transistor that amplifies a first signal; a bias circuit that supplies a bias current or voltage based on a control signal to the first transistor; a second transistor to which a control current based on the control signal is supplied, which has an emitter or a source thereof connected to a collector or a drain of the first transistor, and from which a second signal obtained by amplifying the first signal is output; and a first feedback circuit provided between the collector or the drain of the second transistor and the base or the gate of the second transistor.

Filtering architectures and methods for wireless applications. In some embodiments, a wireless architecture can include a pre-amplifier filter configured to filter a signal, and an amplifier assembly configured to amplify the filtered signal. The wireless architecture 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. In some embodiments, such a wireless architecture can be implemented in a packaged module or a wireless device.

Diversity receiver front end system with tunable input and output matching circuits. A receiving system can include a controller configured to selectively activate one or more of a plurality of paths between an input of the receiving system and an output of the receiving system. The receiving system can include a plurality of amplifiers. Each one of the plurality of amplifiers can be disposed along a corresponding one of the plurality of paths and can be configured to amplify a signal received at the amplifier. The receiving system can include one or more tunable matching circuits. Each one of the one or more tunable matching circuits can disposed at the input or the output and configured to present an impedance based on a tuning signal received from the controller.

A power supply to power amplifier (PA) distribution network may include a first power supply. The PA distribution network may further include at least one power amplifier. The power amplifier may be coupled to the first power supply. The power amplifier may include a driver stage and a power stage. The power amplifier may be coupled to the first power supply via a first switch.

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.

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 non-isolated power supply. A positive power and a negative power are respectively formed by charging a +VCC1 energy storage filter and a ?VCC2 energy storage filter connected in series and discharging the +VCC1 energy storage filter 102 and the ?VCC2 energy storage filter. The output positive and negative power may be differently combined by changing the capacities of the +VCC1 energy storage filter and the ?VCC2 energy storage filter and may be equal or unequal.

An operational amplifier comprises: a first amplifier stage 4 comprising a first differential pair of transistors 8, 10 arranged to receive and amplify a differential input signal 18, 20 thereby providing a first differential output signal 22, 24; and a second amplifier stage 6 comprising a second differential pair of transistors 26, 28 arranged to receive and amplify the first differential output signal 22, 24 thereby providing a second differential output signal 38, 40.

Diversity receiver for wireless applications. In some embodiments, a receiver system can include a controller configured to selectively activate one or more of a plurality of paths between an input and an output, and a plurality of amplifiers, with each one of the plurality of amplifiers disposed along a corresponding one of the plurality of paths and configured to amplify a signal received at the amplifier. The receiving system can further include two or more of features including (a) variable-gain amplifiers, (b) phase-shifting components, (c) impedance matching components, (d) post-amplifier filters, (e) a switching network, and (f) flexible band routing. In some embodiments, such a receiving system can be implemented as a diversity receive module.