Radio frequency signal phase correction in a distributed power management circuit
A distributed power management circuit is disclosed. Herein, a phase correction in a radio frequency (RF) signal is performed by a power management integrated circuit (PMIC), a distributed PMC, and a power amplifier circuit. The power amplifier circuit includes a phase shifter circuit configured to phase-shift the RF signal based on a phase correction signal and a power amplifier configured to amplify the phase-shifted RF signal based on a modulated voltage. The distributed PMIC is configured to generate the phase correction signal and the modulated voltage based on a modulated target voltage. The PMIC is configured to generate the modulated target voltage based on a time-variant power envelope of the RF signal. 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.
1. A distributed power management circuit comprising:
a power amplifier circuit comprising:
a phase shifter circuit configured to phase shift a radio frequency (RF) signal based on a phase correction signal; and
a power amplifier configured to amplify the phase-shifted RF signal based on a modulated voltage;
a distributed power management integrated circuit (PMIC) configured to generate the phase correction signal and the modulated voltage based on a modulated target voltage; and
a PMIC configured to generate the modulated target voltage based on a time-variant power envelope of the RF signal.
2. The distributed power management circuit of claim 1 , wherein:
the PMIC is coupled to the power amplifier via a first conductive path; and
the distributed PMIC is coupled to the power amplifier via a second conductive path shorter than the first conductive path.
3. The distributed power management circuit of claim 1 , wherein the distributed PMIC comprises:
a voltage modulation circuit configured to generate the modulated voltage based on the modulated target voltage; and
a phase correction circuit configured to generate the phase correction signal based on the modulated target voltage to thereby cause the phase shifter circuit to phase-shift the RF signal.
4. The distributed power management circuit of claim 3 , wherein the phase correction circuit comprises a phase correction voltage circuit configured to generate a modulated phase correction voltage based on a phase correction voltage lookup table (LUT) comprising a plurality of phase correction voltages each corresponding to a respective level of the modulated target voltage.
5. The distributed power management circuit of claim 4 , wherein the phase correction circuit further comprises a voltage equalizer circuit configured to equalize the modulated phase correction voltage.
6. The distributed power management circuit of claim 4 wherein the phase correction circuit further comprises a time advance circuit configured to time advance the modulated phase correction voltage by a selected time advance value to generate a time-advanced modulated phase correction voltage that is time aligned with the modulated voltage.
7. The distributed power management circuit of claim 6 , wherein the phase correction circuit is further configured to generate the phase correction signal comprising the time-advanced modulated phase correction voltage.
8. The distributed power management circuit of claim 7 , wherein the phase shifter circuit is further configured to:
determine a phase shift corresponding to the time-advanced modulated phase correction voltage; and
phase-shift the RF signal based on the determined phase shift.
9. The distributed power management circuit of claim 6 , wherein the phase correction circuit further comprises a voltage-to-current conversion circuit configured to convert the time-advanced modulated phase correction voltage into a time-advanced modulated phase correction current.
10. The distributed power management circuit of claim 9 , wherein the phase shifter circuit is further configured to:
determine a phase shift corresponding to the time-advanced modulated phase correction current; and
phase-shift the RF signal based on the determined phase shift.
11. The distributed power management circuit of claim 3 , wherein the voltage modulation circuit comprises:
a voltage amplifier configured to generate an initial modulated voltage based on the modulated target voltage; and
an offset capacitor configured to raise the initial modulated voltage by an offset voltage to generate the modulated voltage.
12. The distributed power management circuit of claim 11 , wherein the voltage amplifier is further configured to generate the initial modulated voltage based on a selected one of a plurality of supply voltages.
13. The distributed power management circuit of claim 12 , wherein the PMIC comprises a supply voltage circuit configured to generate the plurality of supply voltages.
14. The distributed power management circuit of claim 1 , wherein the PMIC comprises a switcher circuit coupled to the power amplifier and configured to provide a low-frequency current to the power amplifier.
15. The distributed power management circuit of claim 14 , wherein the switcher circuit comprises:
a multi-level charge pump (MCP) configured to generate a low-frequency voltage as a function of a battery voltage; and
a power inductor coupled to the MCP and configured to induce the low-frequency current based on the low-frequency voltage.
16. The distributed power management circuit of claim 1 , further comprising a transceiver circuit configured to generate the RF signal associated with the time-variant power envelope.
17. The distributed power management circuit of claim 16 , wherein the transceiver circuit is further configured to provide a time-variant power level of the time-variant power envelope to the PMIC.
18. The distributed power management circuit of claim 17 , wherein the PMIC comprises a target voltage circuit configured to generate the modulated target voltage based on the time-variant power level of the time-variant power envelope.
19. The distributed power management circuit of claim 18 , wherein the target voltage circuit comprises a target voltage lookup table (LUT) configured to correlate the time-variant power level of the time-variant power envelope with a plurality of target voltages.
20. A distributed power management circuit comprising:
a power amplifier circuit comprising:
a phase shifter circuit configured to phase shift a radio frequency (RF) signal based on a phase correction signal; and
a power amplifier configured to amplify the phase-shifted RF signal based on a modulated voltage;
a distributed power management integrated circuit (PMIC) configured to generate the phase correction signal and the modulated voltage based on a modulated target voltage;
a PMIC configured to generate the modulated target voltage based on a time-variant power envelope of the RF signal; and
a transceiver circuit configured to generate the RF signal associated with the time-variant power envelope.