Techniques are disclosed implementing a tunable transformer with additional taps in at least one of the three coils. The tunable transformer enables the resonant frequency within RF transceiver matching networks to be adjusted without substantially impacting the output power at resonance. The tunability of the transformer is partially driven by the insertion of additional coils within the transformer, which are selectively switched and may be further coupled with a tunable capacitance. The tunability of the transformer is further driven via the use of at least one multi-tap transformer coil, which allows electronic components to be coupled to different coil taps to thereby facilitate an adjustable DC inductance. Doing so counteracts changes in mutual inductance between the non-switched coils, and facilitates the stabilization of output power with shifts in resonant frequency.

A radio-frequency circuit includes a first power amplifier that amplifies a first transmission signal and outputs the first transmission signal amplified; and a second power amplifier that amplifies a second transmission signal different in frequency from the first transmission signal, and outputs the second transmission signal amplified. At least one of the first power amplifier or the second power amplifier switches from ET mode to APT mode, when (1) both the first power amplifier and the second power amplifier are outputting amplified transmission signals and (2) output power of at least one of the first power amplifier or the second power amplifier is greater than a first threshold power.

A radio-frequency circuit includes a first power amplifier that amplifies a first transmission signal and outputs the first transmission signal amplified; and a second power amplifier that amplifies a second transmission signal different in frequency from the first transmission signal, and outputs the second transmission signal amplified. At least one of the first power amplifier or the second power amplifier switches from ET mode to APT mode, when (1) both the first power amplifier and the second power amplifier are outputting amplified transmission signals and (2) output power of at least one of the first power amplifier or the second power amplifier is greater than a first threshold power.

Disclosed is a voltage protection circuit for preventing power amplifier burnout in an electronic device. The electronic device includes a power amplifier (PA) configured to amplify a transmission signal, a switch configured to set a path of a signal outputted from the PA, a bias control circuit configured to control the supply of a bias current driving the PA, and a voltage protection circuit configured to provide a main control signal for turning off the PA earlier than turning off the switch based on a battery voltage providing a driving power of the electronic device, and forward the main control signal to the bias control circuit, wherein, in response to receiving the main control signal instructing to turn off the PA from the voltage protection circuit, the bias control unit stops the supply of the bias current driving the PA.

The present disclosure relates to systems and methods for operating transceiver circuitry to transmit or receive signals on various frequency ranges. To do so, a transmitter or a receiver of the transceiver circuitry is selectively coupled to or uncoupled from an antenna of the transceiver circuitry. Additionally, radio frequency filters may be individually or collectively coupled to and/or uncoupled from the antenna to filter different frequencies in the transmitting or receiving signals.

The present disclosure relates to systems and methods for operating transceiver circuitry to transmit or receive signals on various frequency ranges. To do so, a transmitter or a receiver of the transceiver circuitry is selectively coupled to or uncoupled from an antenna of the transceiver circuitry. Additionally, radio frequency filters may be individually or collectively coupled to and/or uncoupled from the antenna to filter different frequencies in the transmitting or receiving signals.

A filter includes series resonators on a signal path, each of the series resonator including an IDT electrode that includes first electrode fingers each including a variant portion, second electrode fingers each including no variant portion, or both the first electrode fingers and the second electrode fingers, in the IDT electrode of one or more series resonators of the series resonators, a direction connecting other-side end portions of electrode fingers crosses an acoustic wave propagation direction, the IDT electrode includes the first electrode fingers, a first portion of an IDT electrode of another series resonator centrally located in the acoustic wave propagation direction, includes only the first electrode fingers, and a second portion and a third portion on two sides of the first portion each include only the second electrode fingers.

A radio-frequency module includes a mounting substrate including a ground electrode layer formed by a planar wiring pattern; multiple ground terminals, which are multiple external connection terminals that are arranged on a first main surface of the mounting substrate and that are set to ground potential; and a first radio-frequency component (for example, a reception filter and/or a low noise amplifier) mounted on the first main surface. The multiple ground terminals are arranged at an outer periphery side of the first main surface with respect to the first radio-frequency component and are connected to the ground electrode layer. In a plan view of the mounting substrate, at least part of the first radio-frequency component is overlapped with the ground electrode layer.

A temperature compensation circuit for a power amplifier is provided, wherein data of circuit configurations corresponding to specific temperatures (including data associated with an output terminal voltage, a bias voltage, an adaptive bias, and a matching impedance of the power amplifier) for the power amplifier is stored in a read-only memory. Therefore, the temperature compensation circuit is capable of reading the data according to a temperature sensing signal to adjust the circuit configuration of the power amplifier accordingly, thereby, in a case of a constant input power of the power amplifier, an output power variance of the power amplifier is within a second interval (e.g., −10%˜+10%) when an environment temperature varies within a first interval. Therefore, the power amplifier has a stable gain.

A temperature compensation circuit for a power amplifier is provided, wherein data of circuit configurations corresponding to specific temperatures (including data associated with an output terminal voltage, a bias voltage, an adaptive bias, and a matching impedance of the power amplifier) for the power amplifier is stored in a read-only memory. Therefore, the temperature compensation circuit is capable of reading the data according to a temperature sensing signal to adjust the circuit configuration of the power amplifier accordingly, thereby, in a case of a constant input power of the power amplifier, an output power variance of the power amplifier is within a second interval (e.g., −10%˜+10%) when an environment temperature varies within a first interval. Therefore, the power amplifier has a stable gain.