Abstract: A barely Doherty dual envelope tracking (BD2E) circuit has a transmitter chain that includes an envelope tracking (ET) circuit that controls a Doherty dual power amplifier array. The ET circuit provides two control signals (supply voltage signals) that are used to control or modulate a carrier amplifier and a peaking amplifier independently of one another. The BD2E circuit includes an improved impedance inverter that isolates the peaking amplifier from the carrier amplifier to allow this independent control. By providing independent control, greater linearity may be provided while preserving the efficiency of the circuit.

Abstract: An envelope tracking (ET) power amplifier apparatus with predistortion includes an amplifier circuit configured to amplify a radio frequency (RF) signal based on an ET voltage and a tracker circuit configured to generate the ET voltage based on an ET target voltage. The amplifier circuit may introduce phase and amplitude distortions to the signal being amplified. To offset such distortions, exemplary aspects of the present disclosure add an isogain predistortion circuit in an ET integrated circuit (IC) to correct for amplitude distortions and add a phase modulation predistortion circuit to correct for phase distortions.

Abstract: An acoustic resonator structure is provided. The acoustic resonator structure includes an acoustic resonator configured to resonate in a first frequency to pass a radio frequency (RF) signal. However, the acoustic resonator may create an electrical capacitance outside the first frequency, which can cause the acoustic resonator to resonate at a second frequency in parallel to the first frequency, thus compromising performance of the acoustic resonator. In this regard, a passive acoustic circuit is provided in parallel to the acoustic resonator in the acoustic resonator structure. The passive acoustic circuit can be configured to resonate in the second frequency to cancel the electrical capacitance created by the acoustic resonator. As such, it may be possible to improve performance of the acoustic resonator without significantly increasing complexity and footprint of the acoustic resonator structure.

Abstract: A multi-voltage generation circuit and related envelope tracking (ET) amplifier apparatus is provided. In one aspect, a multi-voltage generation circuit is configured to generate a number of ET target voltages based on an analog voltage signal. In another aspect, a multi-amplifier ET circuit can be configured to include a number of amplifier circuits for amplifying concurrently a radio frequency (RF) signal based on a number of ET voltages. The multi-amplifier ET circuit also includes a number of driver circuits configured to generate the ET voltages base on a number of ET target voltages. In this regard, the multi-voltage generation circuit can be provided in the multi-amplifier ET circuit to generate the ET target voltages based on the analog voltage signal that corresponds to the RF signal. In examples discussed herein, the driver circuits are co-located with the amplifier circuits to help improve efficiency and maintain linearity in the amplifier circuits.

Abstract: A distributed power management apparatus is provided. The distributed power management apparatus includes an envelope tracking (ET) integrated circuit (ETIC) and a distributed ETIC separated from the ETIC. The ETIC is configured to generate a number of ET voltages for a number of power amplifier circuits and the distributed ETIC is configured to generate a distributed ET voltage(s) for a distributed power amplifier circuit(s). In a non-limiting example, the number of power amplifier circuits and the distributed power amplifier circuit(s) can be disposed on opposite sides (e.g., top and bottom) of a wireless device. As such, in embodiments disclosed herein, the ETIC is provided closer to the power amplifier circuits and the distributed ETIC is provided closer to the distributed power amplifier circuit(s). By providing the ETIC and the distributed ETIC closer to the respective power amplifier circuits, it is possible to reduce trace inductance and unwanted signal distortion.

Abstract: A multi-bandwidth envelope tracking (ET) integrated circuit (IC) (ETIC) is provided. The multi-bandwidth ETIC may be coupled to an amplifier circuit(s) for amplifying a radio frequency (RF) signal modulated in a wide range of modulation bandwidth. In examples discussed herein, the multi-bandwidth ETIC includes an ET voltage circuit configured to generate a modulated voltage based on a supply voltage. The supply voltage may be dynamically adjusted to cause the modulated voltage to transition quickly from one voltage level to another voltage level, particularly when the RF signal is modulated in a higher modulation bandwidth, without compromising efficiency of the ET voltage circuit. As such, the multi-bandwidth ETIC may generate different modulated voltages based on the modulation bandwidth of the RF signal, thus making it possible to employ the multi-bandwidth ETIC in a wide range of wireless communication devices, such as a fifth-generation (5G) wireless communication device.

Abstract: A digital current sensing circuit and related apparatus is provided. In one aspect, a digital current sensing circuit can be configured to estimate a battery current in a coupled circuit based on a voltage corresponding to the battery current. More specifically, the digital current sensing circuit generates an analog sense current proportional to the battery current based on the voltage and digitally processes the analog sense current to generate a battery current indication signal indicative of an estimation of the battery current. In another aspect, a number of digital current sensing circuits can be provided in an apparatus to concurrently estimate a number of battery currents in a number of circuits (e.g., charge pump circuits). As a result, it may be possible to test, debug, and/or fine-tune the apparatus based on the estimated battery currents for improved performance.

Abstract: A power amplifier system having a carrier amplifier having a first supply node, a peaking amplifier having a second supply node, and envelope tracking (ET) circuitry is disclosed. The ET circuitry has a first tracking amplifier that generates a first voltage signal at the first supply node, a second tracking amplifier that generates a second voltage signal at the second supply node, and a transistor coupled between the first supply node and the second supply node. A control circuit has a first input coupled to an output of both or either of the first tracking amplifier and the second tracking amplifier and a control output terminal coupled to a control input terminal of the transistor, wherein the control circuit is configured to progressively turn on the transistor to pass current from the first supply node to the second supply node as the peaking amplifier progressively becomes active.

Abstract: A multi-mode power management apparatus is provided. In embodiments disclosed herein, the multi-mode power management apparatus can be configured to operate in different power management modes across a wide range of modulation bandwidth (e.g., 80 KHz to over 200 MHz). The multi-mode power management apparatus includes a power management integrated circuit (PMIC) and an envelope tracking integrated (ET) circuit (ETIC), which are implemented in separate dies. The PMIC is configured to generate a low-frequency current and a low-frequency voltage. The ETIC is configured to generate a pair of ET voltages. Depending on the power management mode, the multi-mode power management apparatus can selectively output one or more of the ET voltages and the low-frequency voltage to different stages (e.g., driver stage and output stage) of a power amplifier circuit, thus helping to maintain optimal efficiency and linearity of the power amplifier circuit across the wide range of modulation bandwidth.

Abstract: An envelope tracking (ET) power amplifier apparatus is provided. The ET power amplifier apparatus includes a pair of power amplifiers configured to amplify a pair of radio frequency (RF) signals based on a pair of ET voltages. In one aspect, each of the RF signals is split before amplification and recombined after amplification. As such, the power amplifiers can operate based on half the peak power of the RF signals to help improve operating efficiency of the power amplifiers. In another aspect, the RF signals are pre-processed prior to amplification to form a pair of composite RF signals with similar average power such that the power amplifiers can operate based on substantially similar ET voltages. As a result, it may be possible to employ a single ET integrated circuit (ETIC) to provide the ET voltages, thus helping to reduce cost and footprint of the ET power amplifier apparatus.

Abstract: An equalizer circuit and related power management circuit are provided. The power management circuit includes a voltage amplifier circuit configured to generate an envelope tracking (ET) voltage based on a differential target voltage and provide the ET voltage to a power amplifier circuit(s) via a signal path for amplifying a radio frequency signal(s). An equalizer circuit is provided in the power management circuit to equalize the differential target voltage prior to generating the ET voltage. Specifically, the equalizer circuit is configured to provide a transfer function including a second-order complex-zero term and a real-zero term for offsetting a transfer function of an inherent trace inductance of the signal path and an inherent impedance of the voltage amplifier circuit. By employing the second-order transfer function with the real-zero term, it is possible to reduce distortion in the ET voltage, especially when the RF signal(s) is modulated in a wide modulation bandwidth.

Abstract: An adjustable rejection circuit with tunable impedance circuit is disclosed. In particular, a circuit is provided with an impedance tuner configured to match impedances for an antenna. The impedance tuner may include an LC circuit (inductor-capacitor circuit) with one or more elements of the LC circuit being variable. An adjustable rejection circuit may be placed in parallel with the impedance tuner. The adjustable rejection circuit may include a variable negative capacitance element that provides strong attenuation in frequencies of interest.

Abstract: Charge pump tracker circuitry is disclosed having a first switch network configured to couple a first flying capacitor between a voltage input terminal and a ground terminal during a first charging phase and couple the first flying capacitor between the voltage input terminal and a pump output terminal during a first discharging phase. A second switch network is configured to couple a second flying capacitor between the voltage input terminal and the ground terminal during a second charging phase and couple the second flying capacitor between the voltage input terminal and the pump output terminal during a second discharging phase. A switch controller is configured to monitor first and second voltages across the first and second flying capacitors, respectively, during the first and second discharging phases and in response to control the first and second switch networks so that the first the second discharging phases alternate in an interleaved mode.

Abstract: An uplink multiple input-multiple output (MIMO) transmitter apparatus includes a transmitter chain that includes a sigma-delta circuit that creates a summed (sigma) signal and a difference (delta) signal from two original signals to be transmitted. These new sigma and delta signals are amplified by power amplifiers to a desired output level before having two signals reconstructed from the amplified sigma and amplified delta signals by a second circuit. These reconstructed signals match the two original signals in content but are at a desired amplified level relative to the two original signals. The reconstructed signals are then transmitted through respective antennas as uplink signals. By employing this uplink MIMO transmitter apparatus, it is possible to use smaller power amplifiers, which may reduce footprint, power consumption, and costs of the uplink MIMO transmitter apparatus.

Abstract: An adjustable rejection circuit with tunable impedance circuit is disclosed. In particular, a circuit is provided with an impedance tuner configured to match impedances for an antenna. The impedance tuner may include an LC circuit (inductor-capacitor circuit) with one or more elements of the LC circuit being variable. An adjustable rejection circuit may be placed in parallel with the impedance tuner. The adjustable rejection circuit may include a variable negative capacitance element that provides strong attenuation in frequencies of interest.

Abstract: The present disclosure relates to a dual-modulation power management circuit (PMC), which includes a first tracking amplifier coupled to a first voltage port and configured to contribute to a first modulated voltage at the first voltage port, a second tracking amplifier coupled to a second voltage port and configured to contribute to a second modulated voltage at the second voltage port, a charge pump, a power inductor, and a low-dropout (LDO) switch unit. Herein, the power inductor is configured to induce an output current, which is based on a boosted voltage generated by the charge pump, toward the first voltage port. A first portion of the output current is eligible to flow through the LDO switch unit from the first voltage port to the second voltage port. The first modulated voltage is not smaller than the second modulated voltage over time.

Abstract: A fast-switching power management circuit operable to prolong battery life is provided. The power management circuit includes a voltage circuit that can generate an output voltage for amplifying an analog signal in a number of time intervals and a pair of hybrid circuits each causing the output voltage to change in any of the time intervals. A control circuit is configured to activate any one of the hybrid circuits during a preceding one of the time intervals to cause the output voltage to change in an immediately succeeding one of the time intervals. By starting the output voltage change earlier in the preceding time interval, it is possible to complete the output voltage change within a switching window in the succeeding time interval while concurrently reducing rush current associated with the output voltage change, thus helping to prolong battery life in a device employing the power management circuit.

Abstract: A target voltage circuit for fast voltage switching is provided. The target voltage circuit is configured to generate a time-variant target voltage(s) to thereby cause a power management circuit to generate a time-variant voltage(s) for a power amplifier circuit. In embodiments disclosed herein, the target voltage circuit receives a number of data signals (e.g., from a transceiver circuit via a parallel bus) that collectively represent a digital target voltage word and maps the digital target voltage word to a target voltage(s). By receiving the digital target voltage word corresponding to the target voltage(s) via the parallel bus, as opposed to directly receiving the target voltage(s) via a serial bus, it is possible to reduce transmission delay. As a result, the power management circuit will be able to switch the time-variant voltage(s) from one voltage level to another based on the target voltage(s) within a defined temporal limit.

Abstract: The present disclosure relates to an envelope tracking system that is configured to improve the performance of radio frequency power amplifier circuitry by compensating for errors that become more significant as modulation bandwidth increases. These errors include power amplifier collector-base capacitance, time delay between power amplifier stages, and interconnect distance between the baseband modulation source and the power amplifier collector.

Abstract: An envelope tracking integrated circuit having a tracker circuitry configured to generate a modulated supply voltage for a radio frequency power amplifier in response to an envelope of a radio frequency signal to be amplified by the radio frequency power amplifier is disclosed. Also included is a charge pump system configured to generate a tracker supply voltage for the tracker circuitry. Further included is an analog multiplexer configured to receive the tracker supply voltage and a battery source voltage and output a selected one of the tracker supply voltage and the battery source voltage in response to a voltage select signal. A digital processor further included in the envelope tracking integrated circuit is configured to control portions of the tracker circuitry and be powered by the selected one of the tracker supply voltage and the battery source voltage during transmission gaps when the radio frequency signal is not transmitted.