An apparatus includes a first plurality of low noise amplifiers (LNAs) and a cascaded switch configured to route outputs of the first plurality of LNAs to a second plurality of LNAs.

A radio frequency power amplifier (RF PA) apparatus includes a first RF PA, a second RF PA, and a controller. The first RF PA is configured to deliver RF power to a load over a first range of RF power levels. The second RF PA is configured to deliver RF power to the load over a second range of RF power levels greater than the first range of RF power levels. The controller controls whether the first RF PA is delivering RF power to the load or the second RF PA is delivering RF power to the load, and is further configured to coordinate and control handoffs between the first and second RF PAs by varying magnitudes of input RF voltages applied to the RF input ports of the first and second RF PAs or by varying magnitudes of input bias voltages applied to the RF input ports of the first and second RF PAs.

Various embodiments of switched amplifiers are disclosed herein. In some embodiments, a switched amplifier may include a first amplifier; a second amplifier; an input matching network common to both the first and second amplifiers; and at least one switch to couple an input of the switched amplifier, via the input matching network, to one of the first amplifier or the second amplifier. In some embodiments, a switched amplifier may include a first amplifier; a second amplifier; an input matching network common to both the first and second amplifiers or an output matching network common to both the first and second amplifiers; and a bias generation circuit to selectively (1) provide a first bias current to the first amplifier or (2) provide a second bias current to the second amplifier, wherein the second bias current is less than the first bias current.

Aspects of this disclosure relate to a cascode circuit electrically coupled between an amplifier configured to amplify a radio frequency (RF) signal and different loads. The cascode circuit can function as a switch to selectively provide an output from the amplifier to a number of different loads. In certain embodiments, the cascode circuit can be electrically coupled between different stages of a multi-stage power amplifier. For instance, the amplifier can be a first stage of the multi-stage power amplifier and the different loads can include different power amplifier transistors of a second stage of the multi-stage amplifier. The cascode circuit can be implemented by bipolar transistors according to certain embodiments.

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.

An apparatus including: a plurality of amplifiers having a plurality of output ports, respectively, the plurality of amplifiers configured to amplify radio frequency (RF) signals received from at least one antenna; a plurality of demodulators configured to receive the amplified RF signals at a plurality of input ports, respectively, the plurality of demodulators configured to downconvert the received RF signals; and a plurality of switches configured to couple selected output ports of the plurality of amplifiers to selected input ports of the plurality of demodulators, wherein each switch of the plurality of switches is configured such that at least one of the plurality of output ports of the plurality of amplifiers is selectively coupled to any of multiple input ports of the plurality of input ports of the plurality of demodulators.

Aspects of this disclosure relate to an amplifier with at least two chopper amplifier channels in parallel between a shared input and differential nodes. The amplifier can multiplex outputs of the chopper amplifier channels to provide the output of one or more chopper amplifier channels to the differential nodes at a time. In certain embodiments, this can mask dynamic settling errors.

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.

Various embodiments of switched amplifiers are disclosed herein. In some embodiments, a switched amplifier may include a first amplifier; a second amplifier; an input matching network common to both the first and second amplifiers; and at least one switch to couple an input of the switched amplifier, via the input matching network, to one of the first amplifier or the second amplifier. In some embodiments, a switched amplifier may include a first amplifier; a second amplifier; an input matching network common to both the first and second amplifiers or an output matching network common to both the first and second amplifiers; and a bias generation circuit to selectively (1) provide a first bias current to the first amplifier or (2) provide a second bias current to the second amplifier, wherein the second bias current is less than the first bias current.