An analog front-end device includes an amplifier circuit, a first gain control circuit, and a tracking circuit. The amplifier circuit is configured to generate a first output signal according to a first input signal. The first gain control circuit is configured to set a first electronic component according to a first gain control signal and transmit the first input signal to a first input terminal of the amplifier circuit via the first electronic component, in which a terminal of the first electronic component is selectively coupled to the first input terminal or a first predetermined node. The tracking circuit is configured to adjust a level of the first predetermined node according to a level of the first input terminal, in order to reduce a voltage difference between the first input terminal and the first predetermined node.

An analog front-end device includes an amplifier circuit, a first gain control circuit, and a tracking circuit. The amplifier circuit is configured to generate a first output signal according to a first input signal. The first gain control circuit is configured to set a first electronic component according to a first gain control signal and transmit the first input signal to a first input terminal of the amplifier circuit via the first electronic component, in which a terminal of the first electronic component is selectively coupled to the first input terminal or a first predetermined node. The tracking circuit is configured to adjust a level of the first predetermined node according to a level of the first input terminal, in order to reduce a voltage difference between the first input terminal and the first predetermined node.

Described herein are methods for amplifying radio-frequency signals using a variable-gain amplifier with a plurality of input nodes. The methods provide a plurality of gain modes with a low gain mode or bypass mode that follows a bypass path through the variable-gain amplifier and a plurality of higher gain modes that take advantage of tailored impedances for particular gain modes. The tailored impedances can be configured to improve linearity of the amplification process in targeted gain modes. The methods can selectively couple the bypass path to a reference potential node in the plurality of higher gain modes and can selectively decouple the input nodes from a degeneration switching block in the bypass mode.

An electronic device may include wireless circuitry with a processor, a transceiver, an antenna, and a front-end module coupled between the transceiver and the antenna. The front-end module may include one or more radio-frequency amplifiers for amplifying a radio-frequency signal. The radio-frequency amplifier may include input transistors cross-coupled with capacitance neutralization transistors and/or coupled to cascode transistors. One or more n-type gain adjustment transistors may be coupled to source terminals of the capacitance neutralization transistors. One or more p-type gain adjustment transistors may be coupled to source terminals of the cascode transistors. One or more processors in the electronic device can selectively activate one or more of the gain adjustment transistors to reduce the gain of the radio-frequency amplifier without degrading noise performance and without altering the in-band frequency response of the radio-frequency amplifier.

An electronic device may include wireless circuitry with a processor, a transceiver, an antenna, and a front-end module coupled between the transceiver and the antenna. The front-end module may include one or more radio-frequency amplifiers for amplifying a radio-frequency signal. The radio-frequency amplifier may include input transistors cross-coupled with capacitance neutralization transistors and/or coupled to cascode transistors. One or more n-type gain adjustment transistors may be coupled to source terminals of the capacitance neutralization transistors. One or more p-type gain adjustment transistors may be coupled to source terminals of the cascode transistors. One or more processors in the electronic device can selectively activate one or more of the gain adjustment transistors to reduce the gain of the radio-frequency amplifier without degrading noise performance and without altering the in-band frequency response of the radio-frequency amplifier.

Aspects of the disclosure relate to devices, wireless communication apparatuses, methods, and circuitry implementing a low noise amplifier (LNA) with phase-shifting circuitry to achieve a continuous phase at the output of the LNA. One aspect is an amplifier including a high gain active path comprising active circuitry, and a low gain path comprising passive circuitry and phase-shifting circuitry. In one or more aspects, the phase-shifting circuitry is configured to shift a phase of an input signal within the low gain path such that the phase of an output signal outputted from the low gain path approximately matches a phase of an output signal outputted from the high gain active path. In at least one aspect, a gain of the high gain active path is higher than a gain of the low gain passive path.

Technology is disclosed that systematically improves the noise figure (NF) on the receive path of front end architectures. The disclosed technologies tune the elements of the receive path in concert with one another to achieve superior or optimal NF performance. This may occur even where the NF performance of individual components is sub-optimal because it is the combination of the components that is tailored to provide superior or optimal NF performance. The disclosed technologies account for trade-offs in performance that arise when tuning individual components on the receive path, taking a holistic approach to the design of the receive path rather than focusing on optimizing individual elements or selected combinations of elements on the receive path.

Technology is disclosed that systematically improves the noise figure (NF) on the receive path of front end architectures. The disclosed technologies tune the elements of the receive path in concert with one another to achieve superior or optimal NF performance. This may occur even where the NF performance of individual components is sub-optimal because it is the combination of the components that is tailored to provide superior or optimal NF performance. The disclosed technologies account for trade-offs in performance that arise when tuning individual components on the receive path, taking a holistic approach to the design of the receive path rather than focusing on optimizing individual elements or selected combinations of elements on the receive path.

An acoustic structure is provided. The acoustic structure includes an acoustic resonator structure configured to resonate in a series resonance frequency (e.g., passband frequency) to pass a signal, or cause a series capacitance to block the signal in a parallel resonance frequency (e.g., stopband frequency). The parallel resonance frequency may become higher than the series resonance frequency when the tunable capacitance is lesser than or equal to two times of the series capacitance (C.sub.Tune≤2C.sub.0), or lower than the series resonance frequency when the tunable capacitance is greater than two times of the series capacitance (C.sub.Tune>2C.sub.0). In this regard, the acoustic structure can be configured to include a tunable reactive circuit to generate the tunable capacitance (C.sub.Tune) to adjust the parallel resonance frequency. As such, it may be possible to flexibly configure the acoustic resonator structure to block the signal in desired stopband frequencies.

An acoustic structure is provided. The acoustic structure includes an acoustic resonator structure configured to resonate in a series resonance frequency (e.g., passband frequency) to pass a signal, or cause a series capacitance to block the signal in a parallel resonance frequency (e.g., stopband frequency). The parallel resonance frequency may become higher than the series resonance frequency when the tunable capacitance is lesser than or equal to two times of the series capacitance (C.sub.Tune≤2C.sub.0), or lower than the series resonance frequency when the tunable capacitance is greater than two times of the series capacitance (C.sub.Tune>2C.sub.0). In this regard, the acoustic structure can be configured to include a tunable reactive circuit to generate the tunable capacitance (C.sub.Tune) to adjust the parallel resonance frequency. As such, it may be possible to flexibly configure the acoustic resonator structure to block the signal in desired stopband frequencies.