Abstract: Apparatus and methods for sounding reference signal (SRS) switching are provided. In certain embodiments, a controller internal to the power amplifier module initiates a sequence of instructions, in response to a single command from UE. The instructions cause a reduction in RF signal amplitude at the power amplifier output and then cause the antenna switch to actuate. Thus ensuring a single command transition and preventing over-power on the power amplifier and antenna switch. The teachings herein can be used to facilitate reduction in gap times between transitions on different antennas and avoid the use of a blank symbol before and after each SRS symbol.

Abstract: Systems and methods for pulse shaping voltage transitions in envelope tracking systems are provided. In one aspect, a radio frequency module includes a power amplifier configured to receive a radio frequency input signal and a voltage source. The power amplifier further configured to amplify a radio frequency input signal using the voltage source to generate an output radio frequency signal. The radio frequency module further includes a multi-level switch modulator configured to receive an envelope signal indicative of an envelope of the radio frequency input signal and generate the voltage source based on the envelope signal at one of a plurality of discrete voltage levels. The multi-level switch modulator is further configured to generate the voltage source using an analog component during transitions between discrete voltage levels and a digital component following the transitions.

Abstract: A power management device is disclosed, including a first DC-DC converter coupled to a first output voltage line, a second DC-DC converter coupled to a second output voltage line, a first set of switches associated with the first DC-DC converter, and a second set of switches associated with the second DC-DC converter. The power management device may further include a controller configured to toggle one or more switches of the first set of switches and one or more switches of the second set of switches, and a multi-mode radio-frequency front-end block communicatively coupled to the controller.

Abstract: Systems and methods related to power amplification and power supply control. A power amplification control system can include an interface configured to receive a transceiver control signal from a transceiver. The power amplification control system can include a power amplifier control component configured to generate a power amplifier control signal based on the transceiver control signal from the transceiver and a power supply control component configured to generate a power supply control signal based on the transceiver control signal from the transceiver and to generate the power supply control signal based on a local control signal from the power amplifier control component.

Abstract: The present disclosure relates to devices and methods for detecting and preventing occurrence of a saturation state in a power amplifier. A power amplifier module can include a power amplifier including a cascode transistor pair. The cascode transistor pair can include a first transistor and a second transistor. The power amplifier module can include a current comparator configured to compare a first base current of the first transistor and a second base current of the second transistor to obtain a comparison value. The power amplifier module can include a saturation controller configured to supply a reference signal to an impedance matching network based on the comparison value. The impedance matching network can be configured to modify a load impedance of a load line in electrical communication with the power amplifier based at least in part on the reference signal.

Abstract: A power control circuit coupled to a power amplifier, said power control circuit comprising: a first circuit including a power supply and a first transistor to provide a first current to the power amplifier through the first transistor; a second circuit to provide a second current to the power amplifier, the power dissipation of the first current being dependent on the second current of the power amplifier; a protective circuit coupled to the second circuit, the protective circuit configured to pull down a voltage of the second circuit when the temperature of the power control circuit exceeds a threshold temperature, such that the second current provided to the power amplifier by the second circuit is reduced and the power dissipation in the first transistor of the first circuit is reduced with increasing temperature.

Abstract: A method for converting voltage is disclosed, including implementing a first DC-DC converter in a power management unit; implementing a second DC-DC converter in the power management unit; implementing a controller communicatively coupled to a first output line of the first DC-DC converter and communicatively coupled to a second output line of the second DC-DC converter; coupling the power management unit to a supply voltage; and providing one or more output voltages on the first output line and the second output line.

Abstract: Envelope tracking power amplifiers with advanced gain shaping are provided. In certain implementations, a power amplifier system includes a power amplifier that amplifies a radio frequency (RF) signal and an envelope tracker that controls a voltage level of a supply voltage of the power amplifier based on an envelope of the RF signal. The power amplifier system further includes a gain shaping circuit that generates a gain shaping current that changes with the voltage level of the supply voltage from the envelope tracker. For example, the gain shaping circuit can include an analog look-up table (LUT) mapping a particular voltage level of the supply voltage to a particular current level of gain shaping current. Additionally, the gain shaping circuit biases the power amplifier based on the gain shaping current.

Abstract: According to some implementations, a radio-frequency (RF) device includes a communication interface coupled to a serial bus. The RF device also includes a monitoring component coupled to the communication interface, the monitoring component configured to monitor the serial bus for first data transmitted to a first device coupled to the serial bus and configure the RF device based on the first data.

Abstract: Systems and methods for a tunable impedance are provided. A tunable impedance includes a transistor assembly having two terminals and a control input. The transistor assembly includes one or more transistors electrically connected between the two terminals to provide a first impedance between the two terminals, based upon a control signal. One or more replica transistors react to the control signal in a similar fashion as the transistor assembly, to provide a replica impedance based upon the control signal. A control circuit is configured to generate the control signal based upon a voltage across the replica transistor(s) and/or a current through the replica transistor(s).

Abstract: Envelope tracking power amplifiers with advanced gain shaping are provided. In certain implementations, a power amplifier system includes a power amplifier that amplifies a radio frequency (RF) signal and an envelope tracker that controls a voltage level of a supply voltage of the power amplifier based on an envelope of the RF signal. The power amplifier system further includes a gain shaping circuit that generates a gain shaping current that changes with the voltage level of the supply voltage from the envelope tracker. For example, the gain shaping circuit can include an analog look-up table (LUT) mapping a particular voltage level of the supply voltage to a particular current level of gain shaping current. Additionally, the gain shaping circuit biases the power amplifier based on the gain shaping current.

Abstract: A power amplification system comprises a current source configured to provide a bias current, a current mirror configured to mirror the bias current, and a comparator configured to compare the mirrored bias current to a threshold current and, in response to the mirrored bias current exceeding the threshold current, cause a reduction of output power.

Abstract: The present disclosure relates to devices and methods for detecting and preventing occurrence of a saturation state in a power amplifier. A power amplifier module can include a power amplifier including a cascode transistor pair. The cascode transistor pair can include a first transistor and a second transistor. The power amplifier module can include a current comparator configured to compare a first base current of the first transistor and a second base current of the second transistor to obtain a comparison value. The power amplifier module can include a saturation controller configured to supply a reference signal to an impedance matching network based on the comparison value. The impedance matching network can be configured to modify a load impedance of a load line in electrical communication with the power amplifier based at least in part on the reference signal.

Abstract: An amplifier circuit comprising a power amplifier and a protection circuit coupled to the power amplifier. The protection circuit is configured to detect an overdrive condition and, in response to detecting an overdrive condition, apply a clamping status to the protection circuit to reduce a bias current to the power amplifier. The protection circuit has a capacitor and a recovery circuit including: a sensing component configured to monitor a change of charging and discharging currents to and from the capacitor respectively during the clamping status; a first device configured to set a time constant of the recovery circuit; and a second device configured to reset the protection circuit to remove the clamping status when the change of charging or discharging current is beyond a predetermined threshold.

Abstract: In some embodiments, a power supply system for a power amplifier can include a voltage converter implemented generate a first voltage at an output node, and an envelope following circuit implemented to generate and combine a second voltage with the first voltage to provide a combined output voltage for the power amplifier. The combined output voltage can have a waveform that follows one or more peaks of an envelope of a radio-frequency signal above the first voltage.

Abstract: Apparatus and methods for sounding reference signal (SRS) switching are provided. In certain embodiments, a controller internal to the power amplifier module initiates a sequence of instructions, in response to a single command from UE. The instructions cause a reduction in RF signal amplitude at the power amplifier output and then cause the antenna switch to actuate. Thus ensuring a single command transition and preventing over-power on the power amplifier and antenna switch.

Abstract: Apparatus and methods for sounding reference signal (SRS) switching are provided. In certain embodiments, a controller internal to the power amplifier module initiates a sequence of instructions, in response to a single command, that cause the antenna switch to actuate for transmission of the sounding reference signal symbol to a second antenna. The user equipment notifies the base station associated with the mobile device to withhold blanking symbols before and after a sounding reference signal symbol.

Abstract: Apparatus and methods for sounding reference signal (SRS) switching are provided. In certain embodiments, a controller internal to the power amplifier module initiates a sequence of instructions, in response to a single command from UE. The instructions cause a reduction in gain of the power amplifier, and initiate a delay. The antennas switch actuates after the delay to switch from a first antenna to a second antenna. The teachings herein can be used to avoid over-power on the power amplifier and antenna switch.

Abstract: One aspect of this disclosure is a power amplifier module that includes a power amplifier, a semiconductor resistor, a tantalum nitride terminated through wafer via, and a conductive layer electrically connected to the power amplifier. The semiconductor resistor can include a resistive layer that includes a same material as a layer of a bipolar transistor of the power amplifier. A portion of the conductive layer can be in the tantalum nitride terminated through wafer via. The conductive layer and the power amplifier can be on opposing sides of a semiconductor substrate. Other embodiments of the module are provided along with related methods and components thereof.

Abstract: Apparatus and methods for load modulated power amplifiers are provided. In certain embodiments, a load modulated power amplifier system includes a power amplifier that receives a radio frequency signal at an input and provides an amplified radio frequency signal at an output, and a controllable load impedance coupled to the output of the power amplifier. The controllable load impedance receives an envelope signal that changes in relation to an envelope of the radio frequency signal, and the envelope signal is operable to control an impedance of the controllable load impedance to modulate a load at the output of the power amplifier.