Abstract: A packaged module for use in a wireless communication device has a substrate supporting a crystal and a first die that includes at least a microprocessor and one or more of radio frequency transmitter circuitry and radio frequency receiver circuitry. The first die is disposed between the crystal and the substrate. An overmold encloses the first die and the crystal. The substrate also supports a second die that includes at least a power amplifier for amplifying a radio frequency input signal, where the second die is disposed on an opposite side of the substrate from the first die and the crystal.

Abstract: 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.

Abstract: Apparatus and methods for overload protection of low noise amplifiers (LNAs) are provided herein. In certain configurations, an LNA system includes a switch having an analog control input, an LNA configured to provide amplification to a radio frequency (RF) input signal received from the switch, a detector configured to generate a detection current based on detecting a signal level of the LNA, and an error amplifier configured to amplify the detection current to generate an overload protection signal that controls the analog control input.

Abstract: Front-end system having switchable amplifier output stage. In some embodiments, a method for operating a front-end system can include amplifying a signal in a driver stage of a power amplifier, and routing the signal from the driver stage to a selected one of a plurality of output stages, such that the selected output stage further amplifies the signal. The method can further include routing the amplified signal for transmission from the selected output stage to a selected one of a plurality of antennas.

Abstract: Radio frequency amplifiers with overload protection are provided herein. In certain configurations, an RF amplifier system includes an RF amplifier that receives an RF signal from an input terminal and that generates an amplified RF signal at an output terminal, and an overload detection circuit that generates a detection signal indicating a detected signal level of the RF amplifier. The RF amplifier includes an amplification device that amplifies the RF signal and a degeneration circuit that provides degeneration to the amplification device. Additionally, the detection signal is operable to control an amount of degeneration provided by the degeneration circuit so as to protect the RF amplifier from overload.

Abstract: Apparatus and methods for overload protection of low noise amplifiers (LNAs) are provided herein. In certain configurations, an LNA system includes an input switch having an analog control input that controls an impedance of the input switch, an LNA that amplifies a radio frequency (RF) input signal received from the input switch, and an overload protection circuit that provides feedback to the input switch's analog control input based on detecting a signal level of the LNA. The overload protection circuit detects whether or not the LNA is overloaded. Additionally, when the overload protection circuit detects an overload condition, the overload protection circuit provides feedback to the analog control input of the switch to increase the impedance of the switch and reduce the magnitude of the RF input signal received by the LNA.

Abstract: Packaged modules for use in wireless devices are disclosed. A substrate supports integrated circuit die including at least a portion of a baseband system and a front end system, an oscillator assembly, and an antenna. The oscillator assembly includes an enclosure to enclose the oscillator and conductive pillars formed at least partially within a side of the enclosure to conduct signals between the top and bottom surfaces of the oscillator assembly. Components can be vertically integrated to save space and reduce trace length. Vertical integration provides an overhang volume that can include discrete components. Radio frequency shielding and ground planes within the substrate shield the front end system and antenna from radio frequency interference. Stacked filter assemblies include passive surface mount devices to filter radio frequency signals.

Abstract: A packaged module for use in a wireless communication device has a substrate supporting an integrated circuit die that includes at least a microprocessor and radio frequency receiver circuitry and a stacked filter assembly configured as a filter circuit that is in communication with the radio frequency receiver circuitry. The stacked filter assembly includes a plurality of passive components, where each passive component is packaged as a surface mount device. At least one passive component is in direct communication with the substrate and at least another passive component is supported above the substrate by the at least one passive component that is in the direct communication with the substrate.

Abstract: 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.

Abstract: A packaged module for use in a wireless communication device has a substrate supporting a crystal and a first die that includes at least a microprocessor and one or more of radio frequency transmitter circuitry and radio frequency receiver circuitry. The first die is disposed between the crystal and the substrate. An overmold encloses the first die and the crystal. The substrate also supports a second die that includes at least a power amplifier for amplifying a radio frequency input signal, where the second die is disposed on an opposite side of the substrate from the first die and the crystal.

Abstract: Front end systems and related devices, integrated circuits, modules, and methods are disclosed. One such front end system includes a low noise amplifier in a receive path and a multi-mode power amplifier circuit in a transmit path. The low noise amplifier includes a first inductor, an amplification circuit, and a second inductor magnetically coupled to the first inductor to provide negative feedback to linearize the low noise amplifier. The multi-mode power amplifier circuit includes a stacked output stage including a transistor stack of two or more transistors. The multi-mode power amplifier circuit also includes a bias circuit configured to control a bias of at least one transistor of the transistor stack based on a mode of the multi-mode power amplifier circuit. Other embodiments of front end systems are disclosed, along with related devices, integrated circuits, modules, methods, and components thereof.

Abstract: Aspects of this disclosure relate to an impedance transformation circuit for use in an amplifier, such as a low noise amplifier. The impedance transformation circuit includes a matching circuit including a first inductor. The impedance transformation circuit also includes a second inductor. The first and second inductors are magnetically coupled to each other to provide negative feedback to linearize the amplifier.

Abstract: Systems and method related to switchable output stages in power amplifiers. In some embodiments, a power amplifier (PA) circuit can include a driver stage configured to amplify a radio-frequency (RF) signal. The PA circuit can further include a plurality of output stages, with each output stage being configured to be capable of further amplification the RF signal. The PA circuit can further include a switch implemented to route the amplified RF signal from the driver stage to a selected one of the plurality of output stages, such that the selected output stage further amplifies the amplified RF signal.

Abstract: 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.

Abstract: A packaged module for use in a wireless communication device has a substrate supporting an integrated circuit die that includes at least a microprocessor and radio frequency receiver circuitry and a stacked filter assembly configured as a filter circuit that is in communication with the radio frequency receiver circuitry. The stacked filter assembly includes a plurality of passive components, where each passive component is packaged as a surface mount device. At least one passive component is in direct communication with the substrate and at least another passive component is supported above the substrate by the at least one passive component that is in the direct communication with the substrate.

Abstract: Aspects of this disclosure relate to an impedance transformation circuit and overload protection for a low noise amplifier. A low noise amplifier can include a first inductor, an amplification circuit configured to amplify a radio frequency signal, and a second inductor magnetically coupled to the first inductor to provide negative feedback to linearize the low noise amplifier. A switch can be coupled to the amplification circuit of the low noise amplifier. An overload protection circuit can adjust an impedance of the switch based on a signal level associated with the radio frequency signal to provide overload protection for the low noise amplifier.

Abstract: Aspects of this disclosure relate to an impedance transformation circuit for use in an amplifier, such as a low noise amplifier. The impedance transformation circuit includes a matching circuit including a first inductor. The impedance transformation circuit also includes a second inductor. The first and second inductors are magnetically coupled to each other to provide negative feedback to linearize the amplifier.

Abstract: A packaged module for use in a wireless communication device has a substrate supporting a crystal and a first die that includes at least a microprocessor and one or more of radio frequency transmitter circuitry and radio frequency receiver circuitry. The first die is disposed between the crystal and the substrate. An overmold encloses the first die and the crystal. The substrate also supports a second die that includes at least a power amplifier for amplifying a radio frequency input signal, where the second die is disposed on an opposite side of the substrate from the first die and the crystal.

Abstract: A packaged module for use in a wireless communication device has a substrate supporting an integrated circuit die that includes at least a microprocessor and radio frequency receiver circuitry and a stacked filter assembly configured as a filter circuit that is in communication with the radio frequency receiver circuitry. The stacked filter assembly includes a plurality of passive components, where each passive component is packaged as a surface mount device. At least one passive component is in direct communication with the substrate and at least another passive component is supported above the substrate by the at least one passive component that is in the direct communication with the substrate.

Abstract: A packaged module for use in a wireless communication device has a substrate supporting a crystal assembly and a first die that implements at least a portion of a radio frequency baseband subsystem. The crystal assembly, positioned between the first die and the substrate, includes a crystal, an input terminal configured to receive a first signal, an output terminal configured to output a second signal, a conductive pillar, and an enclosure configured to enclose the crystal, where the conductive pillar is formed at least partially within a side of the enclosure and extends from a top surface to a bottom surface of the enclosure. The conductive pillar conducts a third signal distinct from the first and second signals.