Abstract: A power amplifier circuit supporting phase correction in a radio frequency (RF) signal is disclosed. The power amplifier circuit includes a power amplifier configured to amplify an RF signal based on a modulated voltage. The power amplifier circuit also includes a phase correction circuit configured to generate a phase correction signal based on the modulated voltage to thereby cause a phase change in the RF signal before the RF signal is amplified by the power amplifier. As a result, the modulated voltage and the time-variant power envelope can be better aligned in time and/or phase at the power amplifier circuit to thereby improve efficiency and linearity of the power amplifier circuit.

Abstract: A lookup table calibration apparatus and method are disclosed. The lookup table calibration apparatus includes a power amplifier circuit configured to amplify a radio frequency (RF) signal having time-variant power levels based on a modulated voltage. To ensure proper alignment between the modulated voltage and the time-variant power levels, the power amplifier circuit is further configured to phase-shift the RF signal based on a modulated phase correction voltage. Specifically, the modulated voltage is generated based on a modulated voltage lookup table and the modulated phase correction voltage is generated based on a phase correction voltage lookup table. Herein, the lookup table calibration apparatus can be configured to concurrently populate and/or calibrate the modulated voltage lookup table and the phase correction voltage lookup table based on a measured gain and a measured phase of the RF signal, respectively.

Abstract: Time-advanced phase correction in a power amplifier circuit is disclosed. The power amplifier circuit includes a power amplifier that amplifies an analog signal, which is associated with a time-variant power envelope, based on a modulated voltage. To correct phase misalignment between the modulated voltage and the time-variant power envelope, the power amplifier circuit also includes a phase correction circuit that generates a modulated phase correction voltage based on the modulated voltage to thereby cause a phase change in the analog signal. However, the modulated phase correction voltage can lag behind the modulated voltage in time due, in part, to inherent group delay of the phase correction circuit. As such, the power amplifier circuit further includes a time advance circuit to time advance the modulated phase correction voltage to thereby realign the modulated phase correction voltage and the modulated voltage in time for an optimal phase correction in the analog signal.

Abstract: A programmable slave circuit on a communication bus is provided. In a non-limiting example, the communication bus can be a radio frequency front-end (RFFE) bus operating based on a master-slave topology and the programmable slave circuit can be an RFFE slave circuit on the RFFE bus. The programmable slave circuit is configured to receive a high-level command(s) (e.g., a macro word) over the communication bus. A processing circuit in the programmable slave circuit is programmed to generate a low-level command(s) (e.g., a bitmap word) for controlling a coupled circuit(s) based on the high-level command(s). In this regard, it is possible to program or reprogram the processing circuit, for example via over-the-air (OTA) updates, based on the high-level command(s) to be supported, thus making it possible to flexibly customize the programmable slave circuit according to operating requirements and configurations.

Abstract: A power management circuit operable with group delay is provided. The power management circuit includes a transceiver circuit configured to generate a digital target voltage and digitally delay the digital target voltage to generate multiple delayed digital target voltages. Accordingly, the transceiver circuit can generate a windowed digital target voltage in multiple delay tolerance windows based on the delayed digital target voltages. Since the windowed digital target voltage can tolerate a certain amount of group delay in each of the group delay tolerance windows, an envelope tracking (ET) voltage generated based on an analog version of the windowed digital target voltage can therefore tolerate the group delay in each of the group delay tolerance windows as well. As a result, it is possible to avoid distortion in the ET voltage to help improve performance of the power management circuit.

Abstract: Target voltage generation in an envelope tracking (ET) integrated circuit (ETIC) is provided. The ETIC is configured to generate a time-variant ET voltage based on a time-variant target voltage for amplifying a radio frequency (RF) signal modulated for communication in multiple time intervals. In embodiments disclosed herein, the ETIC is self-contained to generate the time-variant target voltage based on a sensed signal having a time-variant sensed envelope that tracks a time-variant power envelope of the RF signal. Since the time-variant target voltage is generated to track the time-variant sensed envelope, which further tracks the time-variant power envelope, the time-variant ET voltage can better track the time-variant power envelope of the RF signal when the time-variant ET voltage is provided to a power amplifier(s) that amplifies the RF signal.

Abstract: A supply voltage circuit for reducing in-rush battery current in an envelope tracking (ET) integrated circuit (ETIC) is provided. The ETIC includes an ET voltage circuit configured to generate a time-variant ET voltage, which includes an offset voltage, in multiple time intervals based on a supply voltage. In some cases, the offset voltage and the supply voltage may both need to be increased or decreased as the time-variant ET voltage increases or decreases. As the offset voltage and the supply voltage increase or decrease, an excessive in-rush battery current may result in a reduced battery life. In this regard, a supply voltage circuit is configured to help the ETIC to adapt the supply voltage on a per-symbol basis. As a result, it is possible to reduce the in-rush battery current in the ETIC while still allowing the time-variant ET voltage to change in a timely manner.

Abstract: An envelope tracking (ET) integrated circuit (ETIC) is provided. The ETIC is configured to generate an ET voltage for amplifying a radio frequency (RF) signal modulated for communication in multiple time intervals. In embodiments disclosed herein, the ETIC is self-contained to generate an ET target voltage based on a power envelope of the RF signal and to generate the ET voltage based on the ET target voltage. Given that the RF signal may be modulated at a very high modulation bandwidth, the ETIC can be configured to modify the ET target voltage in each of the time intervals to thereby cause the ET voltage to be adapted on a per time interval basis. As a result, the ET voltage can better track the power envelope of the RF signal in each of the time intervals to help improve operating efficiency of a power amplifier apparatus that employs the ETIC.

Abstract: A difference between subsequent measures of a second signal when a first signal crosses a threshold value can be used to estimate a delay between the first and second signal. The delay can be used to compensate for delays between an envelope power supply signal and a radio frequency (RF) input signal.

Abstract: An envelope tracking (ET) integrated circuit (ETIC) for reducing in-rush battery current is provided. The ETIC includes an ET voltage circuit configured to generate a time-variant ET voltage, which includes an offset voltage, in multiple time intervals based on a supply voltage. In some cases, the offset voltage and the supply voltage may both need to be increased or decreased as the time-variant ET voltage increases or decreases. As the offset voltage and the supply voltage increase or decrease, an excessive in-rush battery current may be generated in the ETIC to result in a reduced battery life. Hence, the ETIC is configured to avoid increasing or decreasing the offset voltage and the supply voltage in a same one of the time intervals. As a result, it is possible to reduce the in-rush battery current in the ETIC while still allowing the time-variant ET voltage to change in a timely manner.

Abstract: A power management circuit operable to adjust voltage within a defined interval(s) is provided. The power management circuit is configured to generate a time-variant voltage for amplifying an analog signal based on a target voltage. In embodiments disclosed herein, the power management circuit can be configured to generate a lower initial target voltage at a start of the defined interval(s), such as during a cyclic prefix (CP) of an orthogonal frequency division multiplexing (OFDM) symbol, and dynamically adjust the initial target voltage, if necessary, within the defined interval(s) based on a time-variant power envelope of the analog signal. By generating the lower target voltage, in contrast to a conventional method of generating a maximum target voltage, at the start of the defined interval(s), it is possible to reduce energy waste and help improve efficiency in a power amplifier configured to amplify the analog signal based on the time-variant voltage.

Abstract: A radio frequency (RF) switching circuit is provided. The RF switching circuit includes a low-figure-of-merit (FOM) switching path that requires a longer duration to be switched on and off and a high-FOM switching path having a higher FOM than the low-FOM switching path but that can be switched on and off faster than the low-FOM switching path. In one aspect, the RF switching circuit passes an RF signal via the high-FOM switching path while toggling the low-FOM switching path to help reduce overall switching time of the RF switching circuit. In another aspect, the RF switching circuit passes the RF signal via the low-FOM switching path whenever the low-FOM switching path is switched on to help improve overall FOM of the RF switching circuit. As a result, the RF switching circuit may achieve a good overall response time and a reasonable overall FOM.

Abstract: A switch controller for charge pump tracker circuitry is disclosed. The switch controller includes first monitoring circuitry configured to monitor a first voltage across a first flying capacitor during a first discharging phase. A second monitoring circuitry is configured to monitor a second voltage across a second flying capacitor during a second discharging phase. Further included is boost logic circuitry in communication with the first monitoring circuitry and the second monitoring circuitry, wherein the boost logic circuitry is configured in response to control a first switch network coupled to the first flying capacitor and a second switch network coupled to the second flying capacitor so that the first discharging phase and the second discharging phase alternate in an interleaved mode, and so that the first discharging phase and the second discharging phase are in phase during a parallel boost 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: A wide-bandwidth resonant circuit is provided. In an embodiment disclosed herein, the wide-bandwidth resonant circuit includes a positive resonant circuit coupled in parallel to a negative resonant circuit. The positive resonant circuit and the negative resonant circuit can be configured to collectively exhibit certain impedance characteristics across a wide bandwidth. As a result, it is possible to utilize the wide-bandwidth resonant circuit to support a variety of wide-bandwidth applications, such as in a wide-bandwidth signal filter circuit.

Abstract: A dual-mode average power tracking (APT) controller operates in a first mode to move the control voltage quickly without concern for ripple or ringing. When this coarse adjustment takes the control voltage to within a desired margin of a target, the controller may switch to a second mode, where the APT controller more slowly approaches the target, but has reduced ringing or ripples. The mode is changed by changing resistance and capacitance values in a loop filter within the APT circuit. In a further aspect, a pulse shaper circuit may inject a pulse to force the control voltage to change more rapidly. By switching modes in this fashion, the control voltage may quickly reach a desired target, and then remain in the second mode during a transmission time slot such that the control voltage is clean throughout.

Abstract: An envelope tracking (ET) power amplifier apparatus is provided. The multi-mode power amplifier apparatus includes a pair of power amplifiers configured to amplify a radio frequency (RF) signal(s) and an output circuit that outputs the amplified RF signal(s) to a signal output(s). In examples disclosed herein, a control circuit can cause the multi-mode power amplifier apparatus to operate in different power management modes by changing a load impedance coupled to the signal output(s). In a non-limiting example, the control circuit can change a power management mode of the multi-mode power amplifier apparatus based on modulation bandwidth of the RF signal(s). As a result, the multi-mode power amplifier apparatus can operate across a wide range of modulation bandwidth without compromising efficiency and performance.

Abstract: A multi-amplifier envelope tracking (ET) apparatus is provided. The multi-amplifier ET apparatus includes an ET integrated circuit (ETIC). The ETIC includes a first voltage circuit that generates the first ET voltage based on a first supply voltage and a first time-variant target voltage. The ETIC also includes a second voltage circuit that generates the second ET voltage based on a second supply voltage and a second time-variant target voltage. In embodiments disclosed herein, the ETIC is configured to determine the first supply voltage and the second supply voltage in accordance to the first time-variant target voltage and the second time-variant target voltage, respectively. As a result, both the first and the second voltage circuits can operate with optimal efficiency, thus helping to improve overall operating efficiency of the multi-amplifier ET apparatus.

Abstract: A complementary envelope detector contemplates using two pair of mirrored transistors to provide a differential output envelope signal to an associated envelope tracking integrated circuit (ETIC) that supplies control voltages to an array of power amplifiers. While bipolar junction transistors (BJTs) may be used, other exemplary aspects use field effect transistors (FETs). In an exemplary aspect, a first pair are negative channel FETs (nFETs) and a second pair are positive channel FETs (pFETs).

Abstract: An average power tracking (APT) power amplifier apparatus is provided. In a non-limiting example, the APT power amplifier apparatus includes multiple sets of power amplifier circuits configured to amplify a radio frequency (RF) signal(s) for transmission in different polarizations (e.g., vertical and horizontal). In examples disclosed herein, the APT power amplifier apparatus can be configured to employ a single power management integrated circuit (PMIC) to provide an APT voltage to all of the power amplifier circuits for amplifying the RF signal(s). By employing a single PMIC in the APT power amplifier apparatus, it is possible to reduce footprint, power consumption, and costs of the APT power amplifier apparatus.