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.

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.

An embodiment described herein includes a low noise amplifier (LNA) including a plurality of separate input terminals, a plurality of transistors, and an output network coupled to a first reference terminal and a single output of the LNA. Each transistor includes a conduction path and a control terminal coupled to one of the plurality of separate input terminals. The output network is also coupled to the conduction path of each of the plurality of transistors.

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.

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 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 selectable low noise amplifier (LNA) system comprising, a plurality of LNAs having a plurality of LNA characteristics and at least one selection switch network coupled to the plurality of LNAs to select at least one of the plurality of LNAs.

A selectable low noise amplifier (LNA) system comprising, a plurality of LNAs having a plurality of LNA characteristics and at least one selection switch network coupled to the plurality of LNAs to select at least one of the plurality of LNAs.

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.

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.