Voltage control device and power amplification system

Abstract

The present application can provide a voltage control device for controlling the supply voltage of a power amplifier, the voltage control device comprising: a first processing circuit configured to provide a first supply voltage to at least one driver stage amplifier of the power amplifier; and a second processing circuit configured to provide a second supply voltage to an output stage amplifier of the power amplifier, wherein the first supply voltage is generated according to an average power tracking mechanism related to an average power level of a radio frequency signal transmitted by the power amplifier. By using the present application, the supply voltage of the power amplifier can be better controlled.

Description

Technical Field

[0001] This invention relates to a voltage control device, and more particularly to a voltage control device for controlling the supply voltage of a power amplifier (PA) in a transmission (TX) front end. Background Technology

[0002] With the advancement of communication technology, wireless transmission has become an essential function of mobile devices. Furthermore, for wireless transmission, a power amplifier (PA) is an essential component of the transmission front end. The PA is used to amplify the power level of radio frequency (RF) signals to adapt to operating conditions in a wireless environment.

[0003] Due to manufacturing factors and component characteristics, parasitic capacitance may occur inside or outside the PA. This parasitic capacitance can severely degrade the signal integrity of the RF signals transmitted by the PA.

[0004] To address the aforementioned signal integrity issues of PAs, those skilled in the art have dedicated themselves to improving the configuration and operation mechanisms of PAs to achieve better RF signal integrity. Summary of the Invention

[0005] According to one aspect of the present invention, a voltage control device is provided for controlling the power supply voltage of a power amplifier, the voltage control device comprising: a first processing circuit configured to provide a first power supply voltage to at least one driver stage amplifier of the power amplifier; and a second processing circuit configured to provide a second power supply voltage to an output stage amplifier of the power amplifier, wherein the first power supply voltage is generated according to an average power tracking mechanism relating to the average power level of a radio frequency signal transmitted by the power amplifier.

[0006] According to one aspect of the present invention, a power amplification system is provided, comprising: a power amplifier including at least one driver stage amplifier and an output stage amplifier; a first processing circuit configured to generate a first power supply voltage according to an average power tracking mechanism and provide the first power supply voltage to the at least one driver stage amplifier; and a second processing circuit configured to generate a second power supply voltage according to an envelope tracking power modulation mechanism and provide the second power supply voltage to the output stage amplifier.

[0007] By utilizing this invention, the power supply voltage of the power amplifier can be better controlled. Attached Figure Description

[0008] Figure 1 This is a schematic block diagram of the transmission front end 3000 including the exemplary voltage control device 1000 of the present invention.

[0009] Figure 2A This is a graph showing the relationship between the voltage level and time of an RF signal.

[0010] Figure 2B This is a graph showing the relationship between the power supply voltage level and time.

[0011] Figure 3A This is another graph showing the relationship between the voltage level and time of an RF signal.

[0012] Figure 3B This is a graph showing the relationship between the power supply voltage level and time.

[0013] Figure 4 This is a block diagram illustrating an example of a voltage control device and a power amplifier (PA) according to the present invention.

[0014] Figure 5 This is a block diagram illustrating the voltage control device and PA at the TX front end in the comparative example.

[0015] Figure 6 yes Figure 4 A block diagram of an example voltage control device.

[0016] Figure 7A This is a block diagram illustrating another example of the voltage control device and PA of the present invention.

[0017] Figure 7B yes Figure 7A A block diagram of the processing circuit.

[0018] In the following detailed description, numerous specific details are set forth for illustrative purposes in order to provide a thorough understanding of embodiments of the invention. However, one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices may be illustrated schematically for the purpose of simplifying the drawings. Detailed Implementation

[0019] Figure 1 This is a schematic block diagram of the TX front end 3000 including the exemplary voltage control device 1000 of the present invention. (See reference) Figure 1 The TX front end 3000 may include a power supply 1100, a voltage control device 1000, a power amplifier PA 2000, a switch circuit 3100, and an antenna 3200. The TX front end 3000 can be used to wirelessly transmit RF signals from electronic devices.

[0020] PA 2000 can be converted from the modulator (not in...) Figure 1 (As shown in the diagram) The device receives a modulated RF signal rs1, and the RF signal rs1 may have a desired operating frequency suitable for wireless transmission. PA 2000 can be used to amplify the power level of the RF signal rs1 to obtain an RF signal rs2, which may have a desired power level suitable for the operating conditions of the electronic device. Switching circuit 3100 can be used to selectively couple either the TX path txp0 or the receiving (RX) path rxp0 to antenna 3200. When the electronic device is performing a transmission operation, the RF signal rs2 can be transmitted to antenna 3200 through TX path txp0 and switching circuit 3100. Antenna 3200 can be used to generate a radiation signal rs3 based on the RF signal rs2.

[0021] PA 2000 can operate using at least two Direct Current (DC) supply voltages: supply voltage APT1 and supply voltage ET1, which power the PA 2000. The voltage levels of supply voltages APT1 and ET1 are not fixed but can be dynamically adjusted according to the current operating state of the electronic device. For operating states requiring amplification of the RF signal rs2 to a higher power level, supply voltages APT1 and ET1 can be adjusted to a higher voltage level; otherwise, the voltage levels of supply voltages APT1 and ET1 can be decreased.

[0022] Voltage control device 1000 can be used to provide power supply voltages APT1 and ET1 and to adjust their voltage levels. Power supply 1100 can be used to provide power supply voltage VB1 to voltage control device 1000. Power supply voltage VB1 can be a fixed power supply voltage with a fixed voltage level. In one example, power supply 1100 can refer to a battery, and power supply voltage VB1 can be a fixed battery voltage of 1.5 volts.

[0023] Specifically, the power supply voltage APT1 can be referred to as the "first power supply voltage," and the voltage control device 1000 can control the power supply voltage APT1 according to the "Average-Power-Tracking (APT)" mechanism. Furthermore, the power supply voltage ET1 can be referred to as the "second power supply voltage," and ET1 can be controlled according to the "Envelope-Tracking-Supply-Modulating (ETSM)" mechanism.

[0024] Figure 2A This is a graph showing the relationship between the voltage level of the RF signal rs2 and time. Figure 2BThis is a graph showing the relationship between the voltage level of power supply voltage APT1 and time. Figure 2A and Figure 2B Both can illustrate the APT mechanism applied to the supply voltage APT1. (See reference.) Figure 2A The average power level 20 of the RF signal rs2 can be measured, and a control signal ap1 related to the average power level 20 can be obtained. The voltage control device 1000 can be configured to adjust the power supply voltage APT1 according to the control signal ap1. When the average power level 20 of the RF signal rs2 decreases, it indicates that PA 2000 requires lower power, therefore... Figure 2B As shown, the voltage control device 1000 can reduce the voltage level of the power supply voltage APT1. Compared to a fixed power supply voltage VCC0, the power supply voltage APT1 can be dynamically adjusted based on the average power level 20 of the RF signal rs2, thereby reducing the power consumption of PA 2000.

[0025] On the other hand, by utilizing the ETSM mechanism, the power supply voltage ET1 can be continuously (i.e. more frequently and precisely) adjusted according to the envelope of the RF signal rs2, thus further reducing the power consumption of PA 2000. Figure 3A This is another graph showing the relationship between the voltage level of the RF signal rs2 and time. Figure 3B This is a graph showing the relationship between the voltage level of the power supply voltage ET1 and time. Figure 3A and Figure 3B Both can be used to illustrate the ETSM mechanism applied to the power supply voltage ET1. (See reference) Figure 3A It can measure the envelope 30 of the RF signal rs2 and obtain the control signal ev1 related to the envelope 30. For example... Figure 3B As shown, the voltage control device 1000 can be configured to continuously adjust the power supply voltage ET1 according to the control signal ev1. In the ETSM mechanism, the voltage level of the RF signal rs2 can be tracked more accurately, so the power supply voltage ET1 can be adjusted immediately to further reduce the power consumption of PA 2000.

[0026] exist Figure 1 In the example, the average power level 20 and envelope 30 of the RF signal rs2 can be controlled by another element (not in the voltage control device 1000) Figure 1 (As shown in the diagram) Measurements can be taken, and control signals ap1 and ev1 can be generated in this separate element. In other examples (not shown in the diagram) Figure 1 As shown in the figure, the voltage control device 1000 can be used to measure the average power level 20 and envelope 30 of the RF signal rs2, and can generate control signals ap1 and ev1 in the voltage control device 1000.

[0027] The power supply voltage ET1 can be analog or digital. In one example, the power supply voltage ET1 can be an analog modulated power supply voltage referred to as "Power Supply Voltage AET1". In another example, the power supply voltage ET1 can be a digital modulated power supply voltage referred to as "Power Supply Voltage DET1".

[0028] Figure 4 This is a schematic block diagram illustrating an example of the voltage control device 1000 and PA 2000 of the present invention. Figure 4 In the example, the voltage control device 1000 can provide a power supply voltage AET1, which can be an analog modulated power supply voltage. (Reference) Figure 4 The voltage control device 1000 may include processing circuitry 100 and processing circuitry 200. Processing circuitry 100 (which may be referred to as the "first processing circuit") is used to provide power supply voltage APT1 according to control signal ap1 and power supply voltage VB1. In one example, processing circuitry 100 may include a DC-DC converter. The DC-DC converter may be a low-dropout (LDO) DC-DC converter, a buck DC-DC converter, a boost DC-DC converter, or a buck-boost DC-DC converter. The DC-DC converter can convert power supply voltage VB1 to power supply voltage APT1 and adjust the voltage level of power supply voltage APT1 according to control signal ap1.

[0029] Processing circuit 200 (which may be referred to as "second processing circuit") is used to provide power supply voltage AET1 based on control signal ev1 and power supply voltage VB1. Similar to processing circuit 100, processing circuit 200 may also include a DC-DC converter for converting power supply voltage VB1 to power supply voltage AET1. The DC-DC converter of processing circuit 200 may be an LDO DC-DC converter, a buck DC-DC converter, a boost DC-DC converter, or a buck-boost DC-DC converter. Furthermore, processing circuit 200 may utilize an ETSM mechanism to adjust power supply voltage AET1 based on control signal ev1.

[0030] PA 2000 may include a driving stage 700 and an output stage 800. Driving stage 700 may include at least one amplifier, such as driver stage amplifiers 700-1 to 700-n. Driver stage amplifiers 700-1 to 700-n may be coupled to a power supply port Vcc1, which may be coupled to processing circuitry 100 to receive a power supply voltage APT1. PA 2000 may have an internal parasitic capacitance C1, which may be measured on the connection path P1 between power supply port Vcc1 and driver stage amplifiers 700-1 to 700-n. Power supply port Vcc1 may be referred to as the "first power supply port," and capacitance C1 may be referred to as the "first equivalent capacitance," relating to power supply port Vcc1.

[0031] Output stage 800 may include output stage amplifier 800-1. Output stage amplifier 800-1 receives power supply voltage AET1 via power supply port Vcc2. Power supply port Vcc2 (which may be referred to as the "second power supply port") may be coupled to processing circuitry 200 to receive power supply voltage AET1. Another parasitic capacitor C2 inside PA 2000 can be measured on connection path P2 between power supply port Vcc2 and output stage amplifier 800-1. Capacitor C2 may be referred to as the "second equivalent capacitance" and is related to power supply port Vcc2.

[0032] Furthermore, the external parasitic capacitance C3 outside PA2000 can be measured on the connection path P3 between the power supply port Vcc2 and the processing circuit 200. Capacitor C3 can be identified at a location outside PA 2000 and near the power supply port Vcc2. Capacitor C3 is also related to the power supply port Vcc2 and can be referred to as the "third equivalent capacitance".

[0033] Furthermore, capacitor C4 and inductor L1 can be measured on the connection path P3 between power supply port Vcc2 and processing circuit 200. Capacitor C4 and inductor L1 are related to the circuit board wiring, which forms the connection path P3 between power supply port Vcc2 and processing circuit 200. Capacitor C4 can be referred to as the "fourth equivalent capacitance".

[0034] Based on the above configuration of voltage control device 1000 and PA 2000, capacitors C2, C3, and C4 can be formed in parallel relative to connection paths P3 and P2. Therefore, when the output stage amplifier 800-1 is observed from the processing circuit 200 through connection path P3, power supply port Vcc2, and connection path P2, the total equivalent capacitance Ct can be obtained as the sum of capacitors C2, C3, and C4, expressed as equation (1):

[0035] Ct=C2+C3+C4 Equation (1)

[0036] Furthermore, the supply voltage AET1 can have a signal bandwidth BW1 related to the total equivalent capacitance Ct. The smaller the value of the total equivalent capacitance Ct, the larger the signal bandwidth BW1 of the supply voltage AET1 may be. With a larger signal bandwidth BW1, PA 2000 can achieve better linearity and less distortion, thus achieving better signal integrity for the RF signal rs2.

[0037] Figure 5 This is a schematic block diagram illustrating the voltage control device 1000b and PA 2000b of the TX front-end 3000b in the comparative example. (Reference) Figure 5 The voltage control device 1000b can supply only one power supply voltage ET1b to PA 2000b. Driver stage amplifiers 700-1 to 700-n receive the power supply voltage ET1b through power supply port Vcc1, and output stage amplifier 800-1 receives the power supply voltage ET1b through power supply port Vcc2. Capacitors C1 and C5 associated with power supply port Vcc1 can be measured, where capacitor C1 is internally parasitic to PA2000b, and capacitor C5 is external to PA2000b. Similarly, capacitors C3 and C2 associated with power supply port Vcc2 can be measured, where capacitor C2 is internally parasitic to PA2000b, and capacitor C3 is external to PA2000b. Furthermore, capacitor C4 can be measured on the circuit board trace forming connection path P3. Since the power supply voltage ET1b is supplied to the driver stage amplifiers 700-1 to 700-n and the output stage amplifier 800-1 through the power supply ports Vcc1 and Vcc2, the total equivalent capacitance Ctb related to the power supply voltage ET1b can be obtained as the sum of capacitances C1, C5, C2, C3 and C4, expressed as equation (2):

[0038] Ct=C1+C5+C2+C3+C4 Equation (2)

[0039] and Figure 5 Compared to the total equivalent capacitance Ctb of the comparative example, the present invention... Figure 4 The voltage control device 1000 shown can provide a smaller total equivalent capacitance Ct value. Therefore, Figure 4 The voltage control device 1000 can achieve a wider signal bandwidth BW1 for the power supply voltage AET1.

[0040] Figure 6 yes Figure 4 A schematic block diagram of an example voltage control device 1000. (Reference) Figure 6The processing circuit 200 (i.e., the second processing circuit) of the voltage control device 1000 may include a converter 210, an amplifier 220, and a feedback circuit 230. The converter 210 may be a DC-DC converter (e.g., an LDO DC-DC converter, a buck DC-DC converter, a boost DC-DC converter, or a buck-boost DC-DC converter) for converting the power supply voltage VB1 to the power supply voltage AET1. Amplifier 220 can be an analog differential amplifier (e.g., an operational amplifier, OP Amp), which can be used as an error amplifier to provide an error current I_err to converter 210. The error current I_err can be generated based on the control signal ev1 and the feedback signal fb1, and the feedback circuit 230 can be used to provide the feedback signal fb1 according to the power supply voltage AET1. When the voltage level of the power supply voltage AET1 deviates from the control signal ev1 (i.e., the voltage level of the power supply voltage AET1 deviates from the envelope 30 of the RF signal rs2), the error current I_err may have a large current value, and converter 210 can sink or source the control current I_sv to adjust the voltage level of the power supply voltage AET1.

[0041] The processing circuit 100 (i.e., the first processing circuit) of the voltage control device 1000 may include a converter 110. Similar to the converter 210 of the processing circuit 200, the converter 110 may also be a DC-DC converter (e.g., an LDO DC-DC converter, a buck DC-DC converter, a boost DC-DC converter, or a buck-boost DC-DC converter) for converting the power supply voltage VB1 to the power supply voltage APT1. Furthermore, the converter 110 may be configured to adjust the power supply voltage APT1 based on the control signal ap1, such that the voltage level of the power supply voltage APT1 approximately fits the average power level 20 of the RF signal rs2.

[0042] Figure 7A This is a schematic block diagram illustrating another example of the voltage control device 1000c and PA 2000 of the present invention. (See reference) Figure 7A The voltage control device 1000c can be similar to Figure 4 The voltage control device 1000 differs from the voltage control device 1000c in that it can provide a digital power supply voltage DET1. The processing circuit 200c of the voltage control device 1000c can have circuitry capable of processing mixed signals, thereby generating the power supply voltage DET1 as a digitally modulated power supply voltage according to the ETSM mechanism.

[0043] Figure 7B yes Figure 7A A schematic block diagram of the processing circuit 200c. (Reference) Figure 7A The processing circuit 200c can be similar to Figure 6 The processing circuit 200 is different. Figure 6 The amplifier 220 (i.e., the analog differential amplifier) ​​can be replaced by a mixed-signal circuit 220c. The mixed-signal circuit 220c can be used to estimate the error value between the control signal ev1 and the power supply voltage DET1. With this error value, the converter 210c can adjust the power supply voltage DET1 to the desired voltage level to fit the envelope 30 of the RF signal rs2, thereby realizing the ETSM mechanism.

[0044] Those skilled in the art will understand that various modifications and adjustments can be made to the embodiments of the present invention. The description and examples of the present invention are merely exemplary, and the true scope of the invention is indicated by the claims and their equivalents.

Claims

1. A voltage control device for controlling the power supply voltage of a power amplifier, the voltage control device comprising: A first processing circuit is configured to provide a first power supply voltage to at least one driver stage amplifier of the power amplifier; as well as The second processing circuit is configured to provide a second power supply voltage to the output stage amplifier of the power amplifier. The first power supply voltage is generated based on an average power tracking mechanism related to the average power level of the radio frequency signal output by the power amplifier. The second power supply voltage is generated according to an envelope tracking power modulation mechanism that relates to the envelope of the voltage level of the radio frequency signal output by the power amplifier.

2. The voltage control device as described in claim 1, characterized in that, The first processing circuit includes a low-dropout DC-DC converter, a buck DC-DC converter, a boost DC-DC converter, or a buck-boost DC-DC converter.

3. The voltage control device as described in claim 2, characterized in that, The first processing circuit receives a fixed power supply voltage from the power supply and converts the fixed power supply voltage into the first power supply voltage according to the average power tracking mechanism.

4. The voltage control device as described in claim 1, characterized in that, The first power supply voltage is supplied to the at least one driver stage amplifier through a first power supply port, and the power amplifier has a first equivalent capacitance parasitic inside the power amplifier, the first equivalent capacitance being related to the first power supply port.

5. The voltage control device as described in claim 1, characterized in that, The second processing circuit includes an analog differential amplifier, and the second power supply voltage is an analog modulated power supply voltage generated according to the envelope tracking power modulation mechanism.

6. The voltage control device as described in claim 1, characterized in that, The second processing circuit includes a mixed-signal circuit, and the second power supply voltage is a digitally modulated power supply voltage generated according to the envelope tracking power modulation mechanism.

7. The voltage control device as described in claim 1, characterized in that, The second power supply voltage is supplied to the output stage amplifier through the second power supply port. The power amplifier has a second equivalent capacitance parasitic inside the power amplifier, which is related to the second power supply port.

8. The voltage control device as described in claim 7, characterized in that, The second power supply port is also related to a third equivalent capacitor, which is parasitic on the outside of the power amplifier.

9. The voltage control device as described in claim 8, characterized in that, The connection path between the second power supply port and the second processing circuit has a fourth equivalent capacitance, and the second power supply voltage has a signal bandwidth related to the sum of the second equivalent capacitance, the third equivalent capacitance, and the fourth equivalent capacitance.

10. A power amplification system, comprising: A power amplifier, the power amplifier comprising at least one driver stage amplifier and an output stage amplifier; A first processing circuit is configured to generate a first power supply voltage according to an average power point tracking (APTS) mechanism and provide the first power supply voltage to the at least one driver stage amplifier, wherein the first power supply voltage is generated according to the APTS mechanism relating to the average power level of the radio frequency signal output by the power amplifier; and A second processing circuit is configured to generate a second power supply voltage according to an envelope tracking power modulation mechanism and to supply the second power supply voltage to the output stage amplifier, wherein the second power supply voltage is generated according to the envelope tracking power modulation mechanism relating to the voltage level of the radio frequency signal output by the power amplifier.

11. The power amplification system as described in claim 10, characterized in that, The first power supply voltage is related to the average power level of the radio frequency signal transmitted by the power amplifier.

12. The power amplification system as described in claim 10, characterized in that, The first processing circuit includes a low-dropout DC-DC converter, a buck DC-DC converter, a boost DC-DC converter, or a buck-boost DC-DC converter.

13. The power amplification system as described in claim 12, characterized in that, Also includes: The power supply is configured to provide a fixed power supply voltage to the first processing circuit. The first processing circuit converts the fixed power supply voltage into the first power supply voltage according to the average power tracking mechanism.

14. The power amplification system as described in claim 10, characterized in that, Also includes: A first power supply port is connected between the first processing circuit and the at least one driver stage amplifier to transmit the first power supply voltage. The power amplifier has a first equivalent capacitance parasitic inside the power amplifier, and the first equivalent capacitance is related to the first power supply port.

15. The power amplification system as described in claim 10, characterized in that, The second power supply voltage is related to the envelope of the voltage level of the radio frequency signal transmitted by the power amplifier.

16. The power amplification system as described in claim 15, characterized in that, The second power supply voltage is an analog modulated power supply voltage or a digital modulated power supply voltage generated according to the envelope tracking power modulation mechanism.

17. The power amplification system as described in claim 10, characterized in that, Also includes: A second power supply port is connected between the second processing circuit and the output stage amplifier to transmit the second power supply voltage. The power amplifier has a second equivalent capacitance parasitic inside the power amplifier, and the second equivalent capacitance is related to the second power supply port.

18. The power amplification system as described in claim 17, characterized in that, The second power supply port is also related to a third equivalent capacitor, which is parasitic on the outside of the power amplifier.

19. The power amplification system as described in claim 18, characterized in that, Also includes: A connection path, connecting the second power supply port and the second processing circuit, is provided, and the connection path has a fourth equivalent capacitance. The second power supply voltage has a signal bandwidth related to the sum of the second equivalent capacitance, the third equivalent capacitance, and the fourth equivalent capacitance.

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