There is provided mechanisms for enabling linearization of a non-linear electronic device. A method is performed by a linearizer device. The method comprises receiving an input signal destined to be input to the non-linear electronic device. Input-output characteristics of the non-linear electronic device is represented by a model. The model is defined by a mathematical expression, and wherein input-output characteristics of the linearizer device is given by the linearization function. The linearization function is determined by applying a function recursion to the mathematical expression of the model. The method comprises obtaining an output signal by subjecting the input signal to the linearization function. The method comprises providing the output signal, instead of the input signal, as input to the non-linear electronic device, thereby enabling linearization of the non-linear electronic device.

An apparatus is disclosed for phase-shifting signals. In example implementations, the apparatus includes a phase shifter. The phase shifter includes a first port, a second port, a vector modulator coupled to the first port, and a signal phase generator. The signal phase generator includes multiple amplifiers coupled between the vector modulator and the second port. The signal phase generator also includes multiple capacitors that couple the multiple amplifiers together to form a loop. Each respective capacitor of the multiple capacitors is coupled between a respective pair of consecutive amplifiers of the multiple amplifiers to form the loop.

A high-frequency signal transmission-reception circuit includes a plurality of band pass filter groups each including a plurality of band pass filter pairs; a first switch including a plurality of band pass filter-side terminal groups each including a plurality of band pass filter-side terminals, and an antenna-side terminal group; a plurality of couplers configured to output respective signal strengths of high-frequency signals transmitted on a plurality of transmission paths; and a second switch including an input terminal group electrically connected to the plurality of couplers, and an output terminal configured to output a detection signal output from one of the plurality of couplers. The first switch electrically connects one band pass filter-side terminal in one band pass filter-side terminal group and one antenna-side terminal, and also electrically connects one band pass filter-side terminal in another band pass filter-side terminal group and another antenna-side terminal.

An amplifier includes a first and a second differential input ports, and a single-ended output port. The amplifier includes a first and a second transistors, each having a gate, source, and drain terminals. The source terminals are coupled to a reference plane and the gate terminals are coupled to the respective first and second differential input ports. The amplifier includes a Balun having a primary and a secondary transformer winding, the primary transformer winding having one end coupled to the drain terminal of the first transistor, an opposite end coupled to the drain terminal of the second transistor, and a center tap coupled to a bias voltage, and the secondary transformer winding is adjacent to the primary transformer winding and having one end coupled to the single-ended output port and an opposite end open circuited. An electromagnetic field generated at the primary induces a signal at the secondary transformer winding.

A transceiver is configured for a calibration mode of operation in which an impedance of a transmit chain is tuned responsive to a power measurement of a mixed RF calibration signal to form a tuned transmit chain. A direct conversion mixes an RF calibration signal with a DC offset signal to form the mixed calibration signal. During a normal mode of operation, a heterodyne mixer mixes an LO signal with an IF signal to produce an RF signal that is amplified through the tuned transmit chain.

Apparatus and methods for biasing of low noise amplifiers (LNAs) are provided herein. In certain embodiments, an LNA includes at least one transistor that amplifies a radio frequency (RF) input signal, and a bias circuit including a current bias circuit that generates a bias current based on a reference current and a voltage bias circuit that generates at least one input bias voltage for the at least one transistor based on the bias current. The current bias circuit includes a first bias transistor that receives the reference current, a second bias transistor that generates the bias current, and an amplifier that controls a first bias voltage of the first bias transistor to match a second bias voltage of the second bias transistor.

Reconfigurable output baluns for wideband push-pull amplifiers are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a first radio frequency signal of a first frequency band and a second radio frequency signal of a second frequency band, and a front-end system including a push-pull power amplifier that selectively amplifies one of the first radio frequency signal or the second radio frequency signal based on a band control signal. The push-pull power amplifier includes an input balun, an output balun, and a pair of amplifiers coupled between the input balun and the output balun. The band control signal is operable to control an impedance of the output balun.

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.