Tracker circuit

Abstract

The switched capacitor circuit (20) of the tracker circuit (1) has switches (S224 and S225), one end of the switch (S224) is connected to the other electrode of the flying capacitor (C200), the other end of the switch (S224) is connected to one electrode of the flying capacitor (C202), one end of the switch (S225) is connected to the other electrode of the flying capacitor (C201), and the other end of the switch (S225) is connected to one electrode of the flying capacitor (C203).

Description

Technical Field

[0001] This invention relates to tracker circuits. Background Technology

[0002] In recent years, efforts have been made to improve power efficiency by applying envelope tracking (ET) in power amplifier circuits. Patent document 1 discloses a digital envelope tracking (D-ET) mode that selectively supplies multiple discrete voltages based on envelope signals.

[0003] Patent Document 1: US Patent No. 9,755,672

[0004] However, there is a situation where the power efficiency of the D-ET mode decreases as the PAPR (Peak to Average Power Ratio) of the high-frequency signal increases. Summary of the Invention

[0005] Therefore, the present invention provides a tracker circuit that can improve power efficiency in D-ET mode.

[0006] One aspect of the tracker circuit of the present invention includes: a switched capacitor circuit configured to generate a plurality of discrete voltages based on an input voltage; and a power modulation circuit configured to selectively output at least one of the generated plurality of discrete voltages to a power amplifier. The switched capacitor circuit includes: a first flying capacitor, a second flying capacitor, a third flying capacitor, and a fourth flying capacitor; a first smoothing capacitor, a second smoothing capacitor, and a third smoothing capacitor; and a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch, a tenth switch, an eleventh switch, a twelfth switch, a thirteenth switch, and a fourteenth switch. One end of the first switch and one end of the second switch are connected to one of the two electrodes of the first flying capacitor. One end of the third switch and one end of the fourth switch are connected to one of the two electrodes of the second flying capacitor. One end of the fifth switch and one end of the sixth switch are switchably connected to the other electrode of the first flying capacitor and to one of the two electrodes of the third flying capacitor via the thirteenth switch. One end of the seventh switch and one end of the eighth switch are switchably connected to the other electrode of the second flying capacitor and to one of the two electrodes of the fourth flying capacitor via the fourteenth switch. One end of the ninth switch and one end of the tenth switch are connected to the other electrode of the third flying capacitor. One end of the eleventh switch and one end of the twelfth switch are connected to the other electrode of the fourth flying capacitor. The other ends of the first switch, the third switch, and one of the electrodes of the first smoothing capacitor are connected to ground. The other ends of the second switch, the fourth switch, the fifth switch, and the seventh switch are connected to the other electrode of the first smoothing capacitor and one of the electrodes of the second smoothing capacitor. The other ends of the sixth switch, the eighth switch, the ninth switch, and the eleventh switch are connected to the other electrode of the second smoothing capacitor and one of the electrodes of the third smoothing capacitor. The other ends of the tenth switch and the twelfth switch are connected to the other electrode of the third smoothing capacitor. One end of the thirteenth switch is connected to the other electrode of the first flying capacitor. The other end of the thirteenth switch is connected to one of the electrodes of the third flying capacitor. One end of the fourteenth switch is connected to the other electrode of the second flying capacitor. The other end of the fourteenth switch is connected to one of the electrodes of the fourth flying capacitor.

[0007] One aspect of the tracker circuit of the present invention includes: a switched capacitor circuit configured to generate a plurality of discrete voltages based on an input voltage; and a power modulation circuit configured to selectively output at least one of the generated plurality of discrete voltages to a power amplifier. The switched capacitor circuit includes: a first flying capacitor, a second flying capacitor, a third flying capacitor, and a fourth flying capacitor; a first smoothing capacitor, a second smoothing capacitor, and a third smoothing capacitor; and a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch, a tenth switch, an eleventh switch, a twelfth switch, and a thirteenth switch. One end of the first switch and one end of the second switch are connected to one of the two electrodes of the first flying capacitor; one end of the third switch and one end of the fourth switch are connected to one of the two electrodes of the second flying capacitor; one end of the fifth switch and one end of the sixth switch are connected to the other electrode of the first flying capacitor and one of the two electrodes of the third flying capacitor; one end of the seventh switch and one end of the eighth switch are connected to the other electrode of the second flying capacitor and the fourth flying capacitor. One electrode of the two electrodes of the cross capacitor, one end of the ninth switch and one end of the tenth switch are connected to the other electrode of the two electrodes of the third cross capacitor, one end of the eleventh switch and one end of the twelfth switch are connected to the other electrode of the two electrodes of the fourth cross capacitor, the other end of the first switch, the other end of the third switch and one electrode of the two electrodes of the first smooth capacitor are connected to each other, the other end of the second switch, the other end of the fourth switch, the other end of the fifth switch and the other end of the seventh switch are connected to the other electrode of the two electrodes of the first smooth capacitor and one electrode of the two electrodes of the second smooth capacitor, the other end of the sixth switch, the other end of the eighth switch, the other end of the ninth switch and the other end of the eleventh switch are connected to the other electrode of the two electrodes of the second smooth capacitor and one electrode of the two electrodes of the third smooth capacitor, the other end of the tenth switch and the other end of the twelfth switch are connected to the other electrode of the two electrodes of the third smooth capacitor, and one end and the other end of the thirteenth switch are respectively connected to one electrode and the other electrode of the two electrodes of the first smooth capacitor, the second smooth capacitor or the third smooth capacitor.

[0008] One aspect of the tracker circuit of the present invention includes: a switched capacitor circuit having a first mode and a second mode, wherein in the first mode, a plurality of first discrete voltages are generated based on an input voltage, and in the second mode, a plurality of second discrete voltages are generated based on an input voltage; and a power modulation circuit configured to selectively output at least one of the generated plurality of first discrete voltages or a plurality of second discrete voltages to a power amplifier, wherein the number of the plurality of first discrete voltages is greater than the number of the plurality of second discrete voltages.

[0009] According to the present invention, power efficiency can be improved in D-ET mode. Attached Figure Description

[0010] Figure 1A This is a graph showing an example of the power supply voltage shift in APT (Average Power Tracking) mode.

[0011] Figure 1B This is a graph illustrating an example of the shift in power supply voltage under A-ET (Analog Envelope Tracking) mode.

[0012] Figure 1C This is a graph illustrating an example of the shift in power supply voltage under D-ET mode.

[0013] Figure 2 This is a circuit diagram of the communication device according to Embodiment 1.

[0014] Figure 3 This is a circuit diagram of the tracker circuit in Implementation Method 1.

[0015] Figure 4A This is a circuit structure diagram showing the connection state in the first stage of the first mode of the switched capacitor circuit of Embodiment 1.

[0016] Figure 4B This is a circuit structure diagram showing the connection state in the second stage of the first mode of the switched capacitor circuit of Embodiment 1.

[0017] Figure 5A This is a circuit structure diagram showing the connection state in the first stage of the second mode of the switched capacitor circuit of Embodiment 1.

[0018] Figure 5B This is a circuit structure diagram showing the connection state in the second stage of the second mode of the switched capacitor circuit of Embodiment 1.

[0019] Figure 6 This is a diagram illustrating an example of multiple discrete voltages generated by the switched capacitor circuit of Embodiment 1.

[0020] Figure 7 This is a graph showing an example of the time shift of the power supply voltage supplied by the tracker circuit of Embodiment 1 to the power amplifier.

[0021] Figure 8 This is a graph showing an example of the time shift of the power supply voltage supplied by the tracker circuit of Embodiment 1 to the power amplifier.

[0022] Figure 9 This is a circuit structure diagram of a switched capacitor circuit according to a variation of Embodiment 1.

[0023] Figure 10 This is a circuit diagram of the communication device according to Embodiment 2.

[0024] Figure 11 This is a circuit diagram of the switched capacitor circuit in Implementation Method 2.

[0025] Figure 12A This is a circuit structure diagram showing the connection state in the first stage of the first mode of the switched capacitor circuit of Embodiment 2.

[0026] Figure 12B This is a circuit structure diagram showing the connection state in the second stage of the first mode of the switched capacitor circuit in Embodiment 2.

[0027] Figure 13A This is a circuit structure diagram showing the connection state in the first stage of the second mode of the switched capacitor circuit of Embodiment 2.

[0028] Figure 13B This is a circuit structure diagram showing the connection state in the second stage of the second mode of the switched capacitor circuit of Embodiment 2.

[0029] Figure 14 This is a diagram illustrating an example of multiple discrete voltages generated by the switched capacitor circuit of Embodiment 2.

[0030] Figure 15 This is a circuit structure diagram of a switched capacitor circuit in a modified example of implementation method 2. Detailed Implementation

[0031] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, the embodiments described below are either general or specific examples. The numerical values, shapes, materials, constituent elements, arrangements of constituent elements, and connection methods shown in the following embodiments are examples and are not intended to limit the scope of the present invention.

[0032] Furthermore, the figures are schematic diagrams that have been appropriately emphasized, omitted, or scaled to illustrate the invention, and may not be strictly representations. There may be differences in shape, positional relationships, and scale compared to the actual figures. In the figures, substantially identical structures are labeled with the same reference numerals, and there are instances where repeated descriptions have been omitted or simplified.

[0033] In circuit structure, the term "connection" includes not only direct connections via connection terminals and / or wiring conductors, but also connections via other circuit elements. "A can be switched to B" means that the connection and non-connection between A and B can be switched, implying that A is connected to B via a switch. Furthermore, "A is connected to B" includes "A can be switched to B." "C is connected between A and B" means that one end of C is connected to A and the other end of C is connected to B, implying that it is connected in series in the path connecting A and B. The "path connecting A and B" refers to the path formed by the conductors that electrically connect A and B.

[0034] In the following description, the term "terminal" refers to the point where a conductor within an element terminates. Furthermore, when the impedance between conductors is sufficiently low, a terminal may be interpreted not only as a single point, but also as any point on the conductor between elements or the entire conductor.

[0035] In addition, terms such as "parallel" and "perpendicular" that indicate the relationship between elements, terms such as "rectangle" that indicate the shape of elements, and numerical ranges do not only have a strict meaning, but also include substantially equivalent ranges, such as a few percent of error.

[0036] First, as a technique for efficiently amplifying high-frequency signals, we will explain tracking mode, which involves dynamically adjusting the power supply voltage supplied to the power amplifier based on the elapsed time of the high-frequency signal. Tracking mode is a mode that dynamically adjusts the power supply voltage applied to the power amplifier. There are several types of tracking modes; we will refer to [reference needed here]. Figure 1A , Figure 1B as well as Figure 1C This section explains the APT, A-ET, and D-ET modes. Figure 1A , Figure 1B as well as Figure 1C In the diagram, the horizontal axis represents time, and the vertical axis represents voltage. Additionally, the thick solid line represents the power supply voltage, and the thin solid line (waveform) represents the modulation signal.

[0037] Figure 1A This is a graph illustrating an example of power supply voltage shifts in APT mode. Figure 1A In APT mode, based on average power, the power supply voltage is varied into multiple discrete voltage levels per frame.

[0038] A frame is a unit that constitutes a high-frequency signal (modulated signal). For example, in 5G NR (5th Generation New Radio) and LTE (Long Term Evolution), a frame contains 10 subframes, each subframe contains multiple time slots, and each time slot contains multiple symbols. The subframe length is 1ms, and the frame length is 10ms.

[0039] Furthermore, the mode that varies voltage levels based on average power in units of one frame or larger is called APT mode, which is distinguished from the mode that varies voltage levels in units smaller than one frame (e.g., in subframes, time slots, or symbols). For example, the mode that varies voltage levels in units of symbols is called Symbol Power Tracking (SPT) mode, which is distinct from APT mode.

[0040] Figure 1B This is a graph illustrating an example of power supply voltage shifts in A-ET mode. In A-ET mode, the envelope of the modulated signal is tracked by continuously varying the power supply voltage based on the envelope signal.

[0041] The envelope signal is the signal that represents the envelope of the modulated signal. The envelope value is, for example, represented by (I... 2 +Q 2 The square root of (I, Q) is used to represent the constellation point. Here, (I, Q) represents the point on the constellation diagram where the signal has been digitally modulated. (I, Q) is determined, for example, by the BBIC (Baseband Integrated Circuit) based on the transmitted information.

[0042] Figure 1C This is a graph illustrating an example of power supply voltage shifts in D-ET mode. In D-ET mode, the envelope of the modulated signal is tracked by varying the power supply voltage into multiple discrete voltage levels within one frame, based on the envelope signal. In other words, in D-ET, the power supply voltage varies at shorter time intervals than APT.

[0043] (Implementation Method 1)

[0044] The following describes Implementation Method 1.

[0045] [1.1 Circuit structure of communication device 7]

[0046] First, refer to Figure 2 The circuit structure of the communication device 7 in this embodiment will be described. Figure 2 This is a circuit diagram of the communication device 7 in this embodiment.

[0047] also, Figure 2 This is an exemplary circuit structure, and the communication device 7 can be installed using various circuit mountings and any of the circuit technologies available. Therefore, the following description of the communication device 7 should not be interpreted in a limiting way.

[0048] The communication device 7 in this embodiment can be used to provide wireless connectivity. For example, the communication device 7 can be installed in a user terminal (UE) in a cellular network such as a mobile phone, smartphone, tablet computer, or wearable device. In other examples, by installing the communication device 7, wireless connectivity can be provided for IoT (Internet of Things) sensor devices, medical / health monitoring devices, vehicles, unmanned aerial vehicles (UAVs), and automated guided vehicles (AGVs). In yet another example, by installing the communication device 7, wireless connectivity can also be provided using a wireless access point or wireless hotspot.

[0049] like Figure 2 As shown, the communication device 7 includes a tracker circuit 1, a power amplifier 2, a filter 3, an RFIC (Radio Frequency Integrated Circuit) 5, an antenna 6, and a DC power supply 50.

[0050] Tracker circuit 1 can supply power voltage Vcc to power amplifier 2 in D-ET mode. Furthermore, tracker circuit 1 can also supply power voltage Vcc to power amplifier 2 in APT mode. Figure 2 As shown, the tracker circuit 1 includes a pre-regulator circuit 10, a switched capacitor circuit 20, a power modulation circuit 30, an input terminal 41, an output terminal 42, and a digital control circuit 60.

[0051] Input terminal 41 is used to receive DC voltage Vbat from DC power supply 50. Input terminal 41 is connected to DC power supply 50 outside tracker circuit 1 and to pre-regulator circuit 10 inside tracker circuit 1.

[0052] Output terminal 42 is used to supply power supply voltage Vcc to power amplifier 2. Output terminal 42 is connected to power amplifier 2 outside tracker circuit 1 and to power modulation circuit 30 inside tracker circuit 1.

[0053] The pre-regulator circuit 10 can also be referred to as a magnetic regulator or a DC (Direct Current) / DC converter. In this embodiment, the pre-regulator circuit 10 is a single-input single-output buck-boost converter capable of converting the DC voltage Vbat into an adjustable voltage Vcnv. Alternatively, the pre-regulator circuit 10 can also be a buck converter or a boost converter. The pre-regulator circuit 10, for example, can change the adjustable voltage Vcnv based on a control signal from RFIC5. For a detailed circuit structure of the pre-regulator circuit 10, refer to... Figure 3 As will be discussed later. In addition, some or all of the pre-regulator circuit 10 may not be included in the tracker circuit 1.

[0054] The switched capacitor circuit 20 can generate multiple discrete voltages V1, V2, V3, V4, V5, and V6, or V2, V3, V4, V5, and V6, based on the adjustment voltage Vcnv supplied by the pre-regulator circuit 10. Specifically, the switched capacitor circuit 20 has a first mode that generates multiple discrete voltages V1, V2, V3, V4, V5, and V6 (an example of multiple first discrete voltages) based on the adjustment voltage Vcnv, and a second mode that generates multiple discrete voltages V2, V3, V4, V5, and V6 (an example of multiple second discrete voltages) based on the adjustment voltage Vcnv. In this case, the number of discrete voltages V1, V2, V3, V4, V5, and V6 generated in the first mode is greater than the number of discrete voltages V2, V3, V4, V5, and V6 generated in the second mode. For a detailed circuit structure of the switched capacitor circuit 20, use... Figure 3 To be discussed later.

[0055] The power modulation circuit 30 can selectively output at least one voltage from a plurality of discrete voltages generated by the switched capacitor circuit 20 as the power supply voltage Vcc to the power amplifier 2. In other words, the power modulation circuit 30 can select at least one voltage from a plurality of discrete voltages and supply the selected voltage to the power amplifier 2. For a detailed circuit structure of the power modulation circuit 30, use... Figure 3 To be discussed later.

[0056] The digital control circuit 60 can control the pre-conditioner circuit 10, the switched capacitor circuit 20, and the power modulation circuit 30 based on digital control signals from RFIC5. Specifically, the digital control circuit 60 can generate and output control signals CS10 and CS20 for controlling the switches included in the pre-conditioner circuit 10 and the switched capacitor circuit 20, and control signal CS30 for controlling the switches included in the power modulation circuit 30. Regarding the circuit structure of the digital control circuit 60, using... Figure 3As will be discussed later. Furthermore, some or all of the digital control circuit 60 may not be included in the tracker circuit 1.

[0057] The DC power supply 50 is connected to the input terminal 41 of the tracker circuit 1. The DC power supply 50 is capable of supplying a DC voltage Vbat to the tracker circuit 1. As the DC power supply 50, for example, a rechargeable battery can be used, but it is not limited to this.

[0058] Power amplifier 2 is connected between RFIC 5 and filter 3. Furthermore, power amplifier 2 is connected to tracker circuit 1. Power amplifier 2 can amplify the high-frequency signal supplied from RFIC 5 using the power supply voltage Vcc from tracker circuit 1.

[0059] Filter 3 is connected between power amplifier 2 and antenna 6. Filter 3 is a bandpass filter with a passband that includes a specified frequency band. The specified frequency band is the frequency band used in communication systems built using Radio Access Technology (RAT), and is predefined by standardization organizations such as 3GPP (3rd Generation Partnership Project) and IEEE (Institute of Electrical and Electronics Engineers). Examples of communication systems include 5G NR systems, LTE systems, and WLAN (Wireless Local Area Network) systems.

[0060] Antenna 6 transmits high-frequency signals that have passed through filter 3. Alternatively, antenna 6 may not be included in communication device 7.

[0061] also, Figure 2 The circuit structure of the communication device 7 shown is illustrative and not limited thereto. For example, the communication device 7 may also include a baseband signal processing circuit that processes signals using a frequency band lower than that of high-frequency signals.

[0062] [1.2 Circuit structure of tracker circuit 1]

[0063] Next, refer to Figure 3 The circuit structure of tracker circuit 1 is described. Figure 3 This is a circuit structure diagram of tracker circuit 1 in this embodiment.

[0064] also, Figure 3 This is an exemplary circuit structure, and tracker circuit 1 can be installed using various circuit mounting methods and any of the circuit techniques employed. Therefore, the following description of tracker circuit 1 should not be interpreted in a limiting sense.

[0065] As described above, the tracker circuit 1 includes a pre-conditioner circuit 10, a switched capacitor circuit 20, a power modulation circuit 30, and a digital control circuit 60. Furthermore, the tracker circuit 1 may also include a pulse shaping network (PSN) or a filter circuit (neither shown) between the power modulation circuit 30 and the output terminal 42.

[0066] The circuit structures of the pre-regulator circuit 10, the switched capacitor circuit 20, the power modulation circuit 30, and the digital control circuit 60 will be described in turn.

[0067] [1.2.1 Circuit structure of pre-regulator circuit 10]

[0068] First, refer to Figure 3 The circuit structure of the pre-regulator circuit 10 is described.

[0069] The pre-regulator circuit 10 includes an input terminal T101, an output terminal T102, switches S101 to S104, a power inductor L101, and a capacitor C101.

[0070] Input terminal T101 is used to receive DC voltage Vbat. Input terminal T101 is connected to input terminal 41 outside the pre-regulator circuit 10, and connected to switch S101 inside the pre-regulator circuit 10.

[0071] Output terminal T102 is used to supply the adjustment voltage Vcnv to the switched capacitor circuit 20. Output terminal T102 is connected to the input terminal T200 of the switched capacitor circuit 20 outside the pre-regulator circuit 10, and is connected to the switch S103 inside the pre-regulator circuit 10.

[0072] Power inductor L101 is used for boosting and bucking DC voltage Vbat. One end of power inductor L101 is connected to switches S101 and S102, and the other end of power inductor L101 is connected to switches S103 and S104.

[0073] Switch S101 is connected between input terminal T101 and one end of power inductor L101. Switch S102 is connected between one end of power inductor L101 and ground. In this connection structure, by exclusively switching switches S101 and S102 on and off, the DC voltage Vbat can be stepped down.

[0074] Switch S103 is connected between the other end of power inductor L101 and output terminal T102. Switch S104 is connected between the other end of power inductor L101 and ground. In this connection structure, the DC voltage Vbat can be boosted by exclusively switching switches S103 and S104 on and off.

[0075] Capacitor C101 is connected between the path between switch S103 and output terminal T102 and ground. Specifically, one of the two electrodes of capacitor C101 is connected to switch S103 and output terminal T102, and the other electrode of capacitor C101 is connected to ground.

[0076] also, Figure 3 The structure of the pre-regulator circuit 10 shown is an example and is not limited thereto. For example, a portion of switches S101 to S104 may be replaced with diodes. Alternatively, a portion or all of the pre-regulator circuit 10 may not be included in the tracker circuit 1.

[0077] [1.2.2 Circuit structure of switched capacitor circuit 20]

[0078] Next, refer to Figure 3 The circuit structure of the switched capacitor circuit 20 is described below. The switched capacitor circuit 20 has a ladder-shaped circuit structure and is capable of generating multiple discrete voltages V1, V2, V3, V4, V5, and V6, or V2, V3, V4, V5, and V6. Specifically, the switched capacitor circuit 20 includes flying capacitors C200 to C209, smoothing capacitors C210 to C215, switches S200 to S225, input terminal T200, and output terminals T201 to T206. Energy and charge are input from the pre-regulator circuit 10 to node N5 via input terminal T200, and are led out from nodes N1, N2, N3, N4, N5, and N6 to power modulation circuit 30 via output terminals T201, T202, T203, T204, T205, and T206.

[0079] Input terminal T200 is used to receive the adjusted voltage Vcnv from the pre-regulator circuit 10. Input terminal T200 is connected to the pre-regulator circuit 10 outside the switched capacitor circuit 20, and to node N5 inside the switched capacitor circuit 20. However, the node connected to input terminal T200 is not limited to node N5. Input terminal T200 can also be connected to any of nodes N1, N2, N3, N4, N5, and N6.

[0080] Output terminals T201, T202, T203, T204, T205, and T206 are used to supply multiple discrete voltages V1, V2, V3, V4, V5, and V6 to the power modulation circuit 30, respectively. Output terminals T201, T202, T203, T204, T205, and T206 are connected to the power modulation circuit 30 outside the switched capacitor circuit 20, and are connected to nodes N1, N2, N3, N4, N5, and N6, respectively, inside the switched capacitor circuit 20.

[0081] Flying capacitors C200, C201, C202, C203, C204, C205, C206, C207, C208, and C209, sometimes referred to as transfer capacitors, are used to boost and / or buck the adjustment voltage Vcnv supplied from the pre-regulator circuit 10. More specifically, in the first mode, flying capacitors C200, C201, C202, C203, C204, C205, C206, C207, C208, and C209 cause charge to be transferred between the flying capacitors C200, C201, C202, C203, C204, C205, C206, C207, C208, and C209 and nodes N1, N2, N3, N4, N6, N7, N8, N9 ... 5. The movement between N6 and ground ensures that at the six nodes N1, N2, N3, N4, N5 and N6, the following conditions are met: (V6-V5):(V5-V4):(V4-V3):(V3-V2):(V2-V1):(V1-VG) = 1:1:1:1:1:1 and V6 > V5 > V4 > V3 > V2 > V1 > VG. In the second mode, flying capacitors C202, C203, C204, C205, C206, C207, C208, and C209 cause charge to move between flying capacitors C202, C203, C204, C205, C206, C207, C208, and C209 and nodes N2, N3, N4, N5, N6, and ground. This maintains the following conditions at the five nodes N2, N3, N4, N5, and N6: (V6-V5):(V5-V4):(V4-V3):(V3-V2):(V2-VG) = 1:1:1:1:1 and V6 > V5 > V4 > V3 > V2 > VG. Here, VG represents the ground potential. Furthermore, (V6-V5):(V5-V4):(V4-V3):(V3-V2):(V2-V1):(V1-VG) is not limited to 1:1:1:1:1:1, and can be designed as any ratio (e.g., 1:2:3:4:5:6, etc.).

[0082] Flying capacitor C200 is an example of a first flying capacitor. One of the two electrodes of flying capacitor C200 is connected to one end of switch S200 and one end of switch S201. The other electrode of flying capacitor C200 is switchably connected to one end of switch S204 and one end of switch S205 via switch S224.

[0083] Flying capacitor C201 is an example of a second flying capacitor. One of the two electrodes of flying capacitor C201 is connected to one end of switch S202 and one end of switch S203. The other electrode of flying capacitor C201 is switchably connected to one end of switch S206 and one end of switch S207 via switch S225.

[0084] Flying capacitor C202 is an example of a third flying capacitor. One of the two electrodes of flying capacitor C202 is connected to one end of switch S204 and one end of switch S205. The other electrode of flying capacitor C202 is connected to one end of switch S208 and one end of switch S209.

[0085] Flying capacitor C203 is an example of a fourth flying capacitor. One of the two electrodes of flying capacitor C203 is connected to one end of switch S206 and one end of switch S207. The other electrode of flying capacitor C203 is connected to one end of switch S210 and one end of switch S211.

[0086] Flying capacitor C204 is an example of a fifth flying capacitor. One of the two electrodes of flying capacitor C204 is connected to one end of switch S208 and one end of switch S209. The other electrode of flying capacitor C204 is connected to one end of switch S212 and one end of switch S213.

[0087] Flying capacitor C205 is an example of a sixth flying capacitor. One of the two electrodes of flying capacitor C205 is connected to one end of switch S210 and one end of switch S211. The other electrode of flying capacitor C205 is connected to one end of switch S214 and one end of switch S215.

[0088] One of the two electrodes of the flying capacitor C206 is connected to one end of switch S212 and one end of switch S213. The other electrode of the flying capacitor C206 is connected to one end of switch S216 and one end of switch S217.

[0089] One of the two electrodes of the flying capacitor C207 is connected to one end of switch S214 and one end of switch S215. The other electrode of the flying capacitor C207 is connected to one end of switch S218 and one end of switch S219.

[0090] One of the two electrodes of the flying capacitor C208 is connected to one end of switch S216 and one end of switch S217. The other electrode of the flying capacitor C208 is connected to one end of switch S220 and one end of switch S221.

[0091] One of the two electrodes of the flying capacitor C209 is connected to one end of switch S218 and one end of switch S219. The other electrode of the flying capacitor C209 is connected to one end of switch S222 and one end of switch S223.

[0092] Smoothing capacitors C210, C211, C212, C213, C214, and C215 are smoothing capacitors used to maintain and smooth the discrete voltages V1, V2, V3, V4, V5, and V6 at nodes N1, N2, N3, N4, N5, and N6.

[0093] Smoothing capacitor C210 is an example of a first smoothing capacitor, connected between node N1 and ground. Specifically, one of the two electrodes of smoothing capacitor C210 is connected to node N1. On the other hand, the other electrode of smoothing capacitor C210 is connected to ground.

[0094] Smoothing capacitor C211 is an example of a second smoothing capacitor, connected between nodes N1 and N2. Specifically, one of the two electrodes of smoothing capacitor C211 is connected to node N2. On the other hand, the other electrode of smoothing capacitor C211 is connected to node N1.

[0095] Smoothing capacitor C212 is an example of a third smoothing capacitor, connected between nodes N2 and N3. Specifically, one of the two electrodes of smoothing capacitor C212 is connected to node N3. On the other hand, the other electrode of smoothing capacitor C212 is connected to node N2.

[0096] Smoothing capacitor C213 is an example of a fourth smoothing capacitor, connected between nodes N3 and N4. Specifically, one of the two electrodes of smoothing capacitor C213 is connected to node N4. On the other hand, the other electrode of smoothing capacitor C213 is connected to node N3.

[0097] A smoothing capacitor C214 is connected between nodes N4 and N5. Specifically, one of the two electrodes of the smoothing capacitor C214 is connected to node N5. On the other hand, the other electrode of the smoothing capacitor C214 is connected to node N4.

[0098] A smoothing capacitor C215 is connected between nodes N5 and N6. Specifically, one of the two electrodes of the smoothing capacitor C215 is connected to node N6. On the other hand, the other electrode of the smoothing capacitor C215 is connected to node N5.

[0099] Switch S200 is an example of a first switch, connected between the flying capacitor C200 and ground. Specifically, one end of switch S200 is connected to one of the two electrodes of the flying capacitor C200. On the other hand, the other end of switch S200 is connected to ground.

[0100] Switch S201 is an example of a second switch, connected between the flying capacitor C200 and node N1. Specifically, one end of switch S201 is connected to one of the two electrodes of the flying capacitor C200. On the other hand, the other end of switch S201 is connected to node N1.

[0101] Switch S202 is an example of a third switch, connected between the flying capacitor C201 and ground. Specifically, one end of switch S202 is connected to one of the two electrodes of the flying capacitor C201. On the other hand, the other end of switch S202 is connected to ground.

[0102] Switch S203 is an example of a fourth switch, connected between the flying capacitor C201 and node N1. Specifically, one end of switch S203 is connected to one of the two electrodes of the flying capacitor C201. On the other hand, the other end of switch S203 is connected to node N1.

[0103] Switch S204 is an example of a fifth switch, connected between flying capacitors C200 and C202 and node N1. Specifically, one end of switch S204 is switchably connected via switch S224 to the other electrode of flying capacitor C200 and to one electrode of flying capacitor C202. The other end of switch S204 is connected to node N1.

[0104] Switch S205 is an example of a sixth switch, connected between flying capacitors C200 and C202 and node N2. Specifically, one end of switch S205 is switchably connected via switch S224 to the other electrode of flying capacitor C200 and to one electrode of flying capacitor C202. The other end of switch S205 is connected to node N2.

[0105] Switch S206 is an example of a seventh switch, connected between flying capacitors C201 and C203 and node N1. Specifically, one end of switch S206 is switchably connected via switch S225 to the other electrode of flying capacitor C201 and to one electrode of flying capacitor C203. The other end of switch S206 is connected to node N1.

[0106] Switch S207 is an example of an eighth switch, connected between flying capacitors C201 and C203 and node N2. Specifically, one end of switch S207 is switchably connected via switch S225 to the other electrode of flying capacitor C201 and to one electrode of flying capacitor C203. On the other hand, the other end of switch S207 is connected to node N2.

[0107] Switch S208 is an example of a ninth switch, connected between flying capacitors C202 and C204 and node N2. Specifically, one end of switch S208 is connected to the other electrode of flying capacitor C202 and one electrode of flying capacitor C204. On the other hand, the other end of switch S208 is connected to node N2.

[0108] Switch S209 is an example of the tenth switch, connected between flying capacitors C202 and C204 and node N3. Specifically, one end of switch S209 is connected to the other electrode of flying capacitor C202 and one electrode of flying capacitor C204. On the other hand, the other end of switch S209 is connected to node N3.

[0109] Switch S210 is an example of an eleventh switch, connected between flying capacitors C203 and C205 and node N2. Specifically, one end of switch S210 is connected to the other electrode of flying capacitor C203 and one electrode of flying capacitor C205. The other end of switch S210 is connected to node N2.

[0110] Switch S211 is an example of the twelfth switch, connected between flying capacitors C203 and C205 and node N3. Specifically, one end of switch S211 is connected to the other electrode of flying capacitor C203 and one electrode of flying capacitor C205. On the other hand, the other end of switch S211 is connected to node N3.

[0111] Switch S212 is an example of the fifteenth switch, connected between flying capacitors C204 and C206 and node N3. Specifically, one end of switch S212 is connected to the other electrode of the two electrodes of flying capacitor C204 and one electrode of the two electrodes of flying capacitor C206. On the other hand, the other end of switch S212 is connected to node N3.

[0112] Switch S213 is an example of the sixteenth switch, connected between flying capacitors C204 and C206 and node N4. Specifically, one end of switch S213 is connected to the other electrode of the two electrodes of flying capacitor C204 and one electrode of the two electrodes of flying capacitor C206. On the other hand, the other end of switch S213 is connected to node N4.

[0113] Switch S214 is an example of the seventeenth switch, connected between flying capacitors C205 and C207 and node N3. Specifically, one end of switch S214 is connected to the other electrode of flying capacitor C205 and one electrode of flying capacitor C207. On the other hand, the other end of switch S214 is connected to node N3.

[0114] Switch S215 is an example of the eighteenth switch, connected between flying capacitors C205 and C207 and node N4. Specifically, one end of switch S215 is connected to the other electrode of flying capacitor C205 and one electrode of flying capacitor C207. On the other hand, the other end of switch S215 is connected to node N4.

[0115] Switch S216 is connected between flying capacitors C206 and C208 and node N4. Specifically, one end of switch S216 is connected to the other electrode of flying capacitor C206 and one electrode of flying capacitor C208. The other end of switch S216 is connected to node N4.

[0116] Switch S217 is connected between flying capacitors C206 and C208 and node N5. Specifically, one end of switch S217 is connected to the other electrode of flying capacitor C206 and one electrode of flying capacitor C208. The other end of switch S217 is connected to node N5.

[0117] Switch S218 is connected between flying capacitors C207 and C209 and node N4. Specifically, one end of switch S218 is connected to the other electrode of flying capacitor C207 and one electrode of flying capacitor C209. The other end of switch S218 is connected to node N4.

[0118] Switch S219 is connected between flying capacitors C207 and C209 and node N5. Specifically, one end of switch S219 is connected to the other electrode of flying capacitor C207 and one electrode of flying capacitor C209. The other end of switch S219 is connected to node N5.

[0119] Switch S220 is connected between the flying capacitor C208 and node N5. Specifically, one end of switch S220 is connected to the other electrode of the flying capacitor C208. On the other hand, the other end of switch S220 is connected to node N5.

[0120] Switch S221 is connected between the flying capacitor C208 and node N6. Specifically, one end of switch S221 is connected to the other electrode of the flying capacitor C208. On the other hand, the other end of switch S221 is connected to node N6.

[0121] Switch S222 is connected between the flying capacitor C209 and node N5. Specifically, one end of switch S222 is connected to the other electrode of the flying capacitor C209. On the other hand, the other end of switch S222 is connected to node N5.

[0122] Switch S223 is connected between the flying capacitor C209 and node N6. Specifically, one end of switch S223 is connected to the other electrode of the flying capacitor C209. On the other hand, the other end of switch S223 is connected to node N6.

[0123] Switch S224 is an example of a thirteenth switch, connected between flying capacitors C200 and C202, and switches S204 and S205. Specifically, one end of switch S224 is connected to the other electrode of flying capacitor C200. Conversely, the other end of switch S224 is connected to one electrode of flying capacitor C202, one end of switch S204, and one end of switch S205. By disconnecting switch S224, flying capacitor C200 is no longer connected to flying capacitor C202.

[0124] Switch S225 is an example of the fourteenth switch, connected between flying capacitors C201 and C203, and switches S206 and S207. Specifically, one end of switch S225 is connected to the other electrode of flying capacitor C201. On the other hand, the other end of switch S225 is connected to one electrode of flying capacitor C203, one end of switch S206, and one end of switch S207. By disconnecting switch S225, flying capacitor C201 is no longer connected to flying capacitor C203.

[0125] [1.2.3 Circuit structure of power modulation circuit 30]

[0126] Next, refer to Figure 3 The circuit structure of the power modulation circuit 30 is described below. The power modulation circuit 30 includes input terminals T301 to T306, output terminal T307, and switches S301 to S306.

[0127] Input terminals T301, T302, T303, T304, T305, and T306 are terminals for receiving multiple discrete voltages V1, V2, V3, V4, V5, and V6 generated by the switched capacitor circuit 20. Outside the power modulation circuit 30, input terminals T301, T302, T303, T304, T305, and T306 are connected to the output terminals T201, T202, T203, T204, T205, and T206 of the switched capacitor circuit 20, respectively. Inside the power modulation circuit 30, they are connected to switches S301, S302, S303, S304, S305, and S306, respectively.

[0128] Output terminal T307 is used to selectively supply at least one of a plurality of discrete voltages V1, V2, V3, V4, V5, and V6 to power amplifier 2. Output terminal T307 is connected to output terminal 42 outside power modulation circuit 30, and connected to switches S301, S302, S303, S304, S305, and S306 inside power modulation circuit 30.

[0129] Switch S301 is connected between input terminal T301 and output terminal T307. Switch S302 is connected between input terminal T302 and output terminal T307. Switch S303 is connected between input terminal T303 and output terminal T307. Switch S304 is connected between input terminal T304 and output terminal T307. Switch S305 is connected between input terminal T305 and output terminal T307. Switch S306 is connected between input terminal T306 and output terminal T307.

[0130] These switches S301, S302, S303, S304, S305, and S306 are switched on and off (opened and closed) by a control signal CS30 from the digital control circuit 60. In this embodiment, switches S301, S302, S303, S304, S305, and S306 are controlled to be exclusively on. That is, they are controlled so that only one of switches S301, S302, S303, S304, S305, and S306 is closed, and the remaining switches S301, S302, S303, S304, S305, and S306 are all off. As a result, the power modulation circuit 30 can select one voltage from a plurality of discrete voltages (V1, V2, V3, V4, V5, and V6) to supply to the power amplifier 2.

[0131] also, Figure 3 The structure of the power modulation circuit 30 shown is an example and is not limited thereto. In particular, switches S301, S302, S303, S304, S305, and S306 can selectively connect at least one of the six input terminals T301, T302, T303, T304, T305, and T306 to the output terminal T307, and can have any structure and be arbitrarily controlled. For example, two of the switches S301, S302, S303, S304, S305, and S306 can be closed, while the remaining four switches S301, S302, S303, S304, S305, and S306 can be open.

[0132] [1.2.4 Circuit Structure of Digital Control Circuit 60]

[0133] Next, refer to Figure 3 The circuit structure of the digital control circuit 60 is described below. The digital control circuit 60 includes a first controller 61 and a second controller 62.

[0134] The first controller 61 processes the serial data signals (CLK, DATA) supplied from RFIC5 to generate control signals CS10 and CS20 for controlling the pre-regulator circuit 10 and the switched capacitor circuit 20. Control signal CS10 controls the on / off state of switches S101 to S104 included in the pre-regulator circuit 10. Control signal CS20 controls the on / off state of switches S200 to S225 included in the switched capacitor circuit 20. Feedback signals for controlling the pre-regulator circuit 10 can also be input to the first controller 61.

[0135] As a serial data signal, a digital control signal using source synchronization can be used, for example. Alternatively, a clock-embedded digital control signal can also be used as a serial data signal. Furthermore, the first controller 61 can also generate control signals for controlling the power modulation circuit 30.

[0136] In this embodiment, a set of clock signals (CLK) and data signals (DATA) are shared in the pre-conditioner circuit 10 and the switched capacitor circuit 20, but this is not a limitation. For example, a set of clock signals and data signals may be used independently in the pre-conditioner circuit 10 and the switched capacitor circuit 20, respectively.

[0137] The second controller 62 processes the parallel data signal supplied from RFIC5 to generate a control signal CS30 for controlling the power modulation circuit 30. The parallel data signal may be, for example, a Digital Control Level (DCL) signal (DCL1, DCL2, DCL3). The DCL signals (DCL1, DCL2, DCL3) are generated by RFIC5 based on the envelope signal of a high-frequency signal. The control signal CS30 is used to control the on / off state of switches S301, S302, S303, S304, S305, and S306 included in the power modulation circuit 30.

[0138] The DCL signals (DCL1, DCL2, DCL3) are each 1-bit signals. Multiple discrete voltages V1, V2, V3, V4, V5, and V6 are each represented by a combination of two 1-bit signals. For example, V1, V2, V3, V4, V5, and V6 are represented by "000", "001", "010", "011", "110", and "111", respectively. Voltage levels can also be expressed using Gray code.

[0139] Furthermore, in this embodiment, the control of the power modulation circuit 30 uses three DCL signals, but the number of DCL signals is not limited to this. For example, one, two, or more than four DCL signals can be used depending on the number of selectable voltage levels of each power modulation circuit 30. In addition, the parallel data signals used in the control of the power modulation circuit 30 are not limited to DCL signals.

[0140] [1.3 Control method for switched capacitor circuit 20]

[0141] Next, refer to Figure 4A , Figure 4B , Figure 5A as well as Figure 5B The control method of the switched capacitor circuit 20 in this embodiment will be described.

[0142] [1.3.1 First Mode]

[0143] First, refer to Figure 4A and Figure 4B The first mode will be explained. Figure 4A This is a circuit structure diagram showing the connection state in the first stage of the first mode of the switched capacitor circuit 20 of this embodiment. Figure 4B This is a circuit structure diagram showing the connection state in the second stage of the first mode of the switched capacitor circuit 20 in this embodiment.

[0144] The first mode is used by the switched capacitor circuit 20 to generate six discrete voltages V1, V2, V3, V4, V5, and V6. In other words, in the first mode, the switched capacitor circuit 20 constitutes a 6-stage switched capacitor.

[0145] In the first mode, the first and second phases are repeated alternately based on the control signal CS20 from the digital control circuit 60.

[0146] In the first phase of the first mode, such as Figure 4A As shown, the first set of switches S200, S203, S204, S207, S208, S211, S212, S215, S216, S219, S220, and S223 are closed, and the second set of switches S201, S202, S205, S206, S209, S210, S213, S214, S217, S218, S221, and S222 are open. Furthermore, switches S224 and S225 are closed.

[0147] In the second phase of the first mode, such as Figure 4BAs shown, the first set of switches S200, S203, S204, S207, S208, S211, S212, S215, S216, S219, S220, and S223 are open, and the second set of switches S201, S202, S205, S206, S209, S210, S213, S214, S217, S218, S221, and S222 are closed. Furthermore, switches S224 and S225 are closed.

[0148] In this first mode, the first set of switches and the second set of switches switch on and off in the first and second stages. On the other hand, switches S224 and S225 remain closed in the first and second stages.

[0149] By repeating this first and second stage, the flying capacitors C200, C201, C202, C203, C204, C205, C206, C207, C208, and C209 can be charged and discharged complementaryly. For example, in one of the first and second stages, charging of the smoothing capacitors C210, C211, C212, C213, C214, and C215 is performed from the flying capacitors C200, C202, C204, C206, and C208; and in the other of the first and second stages, charging of the smoothing capacitors C210, C211, C212, C213, C214, and C215 is performed from the flying capacitors C201, C203, C205, C207, and C209. In other words, since the smoothing capacitors C210, C211, C212, C213, C214, and C215 are always charged by any one of the flying capacitors C200, C201, C202, C203, C204, C205, C206, C207, C208, and C209, even if the current flows at high speed from any one of nodes N1, N2, N3, N4, N5, and N6 to the power modulation circuit 30, the charge will be replenished at high speed to any one of nodes N1, N2, N3, N4, N5, and N6, thus suppressing the potential changes of nodes N1, N2, N3, N4, N5, and N6.

[0150] Through this operation, the switched capacitor circuit 20 can maintain nearly equal voltages across each of the smoothing capacitors C210, C211, C212, C213, C214, and C215. Specifically, at the six nodes N1, N2, N3, N4, N5, and N6, labeled V1, V2, V3, V4, V5, and V6, multiple discrete voltages V1, V2, V3, V4, V5, and V6 are maintained, satisfying (V6-V5):(V5-V4):(V4-V3):(V3-V2):(V2-V1):(V1-VG)=1:1:1:1:1:1:1. For example, when the adjustment voltage Vcnv supplied from the pre-regulator circuit 10 is 5V, the switched capacitor circuit 20 can generate (1V, 2V, 3V, 4V, 5V, 6V) as 6 discrete voltages (V1, V2, V3, V4, V5, V6).

[0151] [1.3.2 Second Mode]

[0152] Next, refer to Figure 5A and Figure 5B The second mode will be explained. Figure 5A This is a circuit structure diagram showing the connection state in the first stage of the second mode of the switched capacitor circuit 20 in this embodiment. Figure 5B This is a circuit structure diagram showing the connection state in the second stage of the second mode of the switched capacitor circuit 20 in this embodiment.

[0153] The second mode is used by the switched capacitor circuit 20 to generate five discrete voltages V2, V3, V4, V5, and V6. In other words, in the second mode, the switched capacitor circuit 20 constitutes a 5-stage switched capacitor.

[0154] In the second mode, the first and second stages are repeated alternately based on the control signal CS20 from the digital control circuit 60.

[0155] In the first phase of the second mode, such as Figure 5A As shown, the third group of switches S204, S207, S208, S211, S212, S215, S216, S219, S220, and S223 are closed, and the fourth group of switches S205, S206, S209, S210, S213, S214, S217, S218, S221, and S222 are open. Furthermore, switches S200, S201, S202, and S203 are closed, and switches S224 and S225 are open.

[0156] In the second phase of the second mode, such as Figure 5BAs shown, the third group of switches S204, S207, S208, S211, S212, S215, S216, S219, S220, and S223 are open, and the fourth group of switches S205, S206, S209, S210, S213, S214, S217, S218, S221, and S222 are closed. Furthermore, switches S200, S201, S202, and S203 are closed, while switches S224 and S225 are open.

[0157] In this second mode, the third and fourth sets of switches switch on and off in the first and second stages. On the other hand, switches S200, S201, S202, and S203 remain closed in the first and second stages, while switches S224 and S225 remain open in the first and second stages.

[0158] By repeating this first and second stage, the flying capacitors C202, C203, C204, C205, C206, C207, C208, and C209 can be charged and discharged complementaryly. For example, in one of the first and second stages, the smoothing capacitors C211, C212, C213, C214, and C215 are charged from the flying capacitors C202, C204, C206, and C208; and in the other of the first and second stages, the smoothing capacitors C211, C212, C213, C214, and C215 are charged from the flying capacitors C203, C205, C207, and C209. In other words, since the smoothing capacitors C211, C212, C213, C214, and C215 are always charged by any one of the flying capacitors C202, C203, C204, C205, C206, C207, C208, and C209, even if the current flows at high speed from any one of nodes N2, N3, N4, N5, and N6 to the power modulation circuit 30, the charge can be replenished at high speed to any one of nodes N2, N3, N4, N5, and N6, thereby suppressing the potential changes of nodes N2, N3, N4, N5, and N6.

[0159] By operating in this way, the switched capacitor circuit 20 can maintain nearly equal voltages across each of the smoothing capacitors C211, C212, C213, C214, and C215. Specifically, at the five nodes N2, N3, N4, N5, and N6, labeled V2, V3, V4, V5, and V6, multiple discrete voltages V2, V3, V4, V5, and V6 are maintained, satisfying (V6-V5):(V5-V4):(V4-V3):(V3-V2):(V2-VG) = 1:1:1:1:1. For example, when the adjustment voltage Vcnv supplied from the pre-regulator circuit 10 is 5V, the switched capacitor circuit 20 can generate (1.25V, 2.5V, 3.75V, 5V, 6.25V) as five discrete voltages (V2, V3, V4, V5, V6) in the second mode.

[0160] [1.4 Multiple discrete voltages generated in the first and second modes]

[0161] Next, refer to Figure 6 The multiple discrete voltages generated by the switched capacitor circuit 20 of this embodiment will be explained. Figure 6 This is a diagram illustrating an example of multiple discrete voltages generated by the switched capacitor circuit 20 of this embodiment. Furthermore, in Figure 6 In this context, the power supply voltage Vcc corresponding to the peak power of the high-frequency signal amplified by power amplifier 2 is 6V.

[0162] For example, in the first mode, a 5V adjustment voltage Vcnv is supplied from the pre-regulator circuit 10 to the switched capacitor circuit 20. In this case, the switched capacitor circuit 20 can generate six discrete voltages (1V, 2V, 3V, 4V, 5V, 6V).

[0163] For example, in the second mode, a 4.8V adjustment voltage Vcnv is supplied from the pre-regulator circuit 10 to the switched capacitor circuit 20. In this case, the switched capacitor circuit 20 can generate five discrete voltages (1.2V, 2.4V, 3.6V, 4.8V, 6V).

[0164] [1.5 Power supply voltage supplied to power amplifier 2]

[0165] Here, refer to Figure 7 and Figure 8 The power supply voltages Vcc1 and Vcc2 supplied to the power amplifier 2 in the first and second modes will be explained.

[0166] [1.5.1 Power Supply Voltage for the First High-Frequency Signal with a Larger PAPR]

[0167] First, refer to Figure 7The power supply voltage Vcc supplied for amplifying the first high-frequency signal with a PAPR above the threshold is explained. Figure 7 This is a graph illustrating an example of the time shift of the power supply voltages Vcc1 and Vcc2 supplied by the power amplifier 2, as described by the tracker circuit 1 of this embodiment. Figure 7 In the diagram, the horizontal axis represents time. The solid line represents the power supply voltage Vcc1 available in the first mode, and the dashed line represents the power supply voltage Vcc2 available in the second mode. Additionally, the envelope signal RF1 represents the envelope signal of the first high-frequency signal.

[0168] exist Figure 7 In both the first and second modes, three discrete voltages V4, V5, and V6, which are higher than a predetermined voltage (e.g., the power supply voltage corresponding to the average power of the first high-frequency signal), can be used for power supply voltages Vcc1 and Vcc2. In this case, the power supply voltage Vcc2 available in the second mode can track the envelope signal RF1 of the first high-frequency signal to a lower voltage compared to the power supply voltage Vcc1 available in the first mode. Therefore, in Figure 7 In this context, the second mode achieves higher power efficiency than the first mode. That is, when the PAPR of the high-frequency signal amplified by power amplifier 2 is above a threshold, applying the second mode to the switched capacitor circuit 20 improves power efficiency.

[0169] At this point, the threshold value can be determined in advance based on experience and / or through experimentation. Furthermore, the PAPR of high-frequency signals can be measured using an RF power detector.

[0170] [1.5.2 Power Supply Voltage for a Second High-Frequency Signal with a Smaller PAPR]

[0171] Next, refer to Figure 8 The power supply voltage Vcc supplied for amplifying the second high-frequency signal with PAPR less than the threshold is explained. Figure 8 This is a graph illustrating an example of the time shift of the power supply voltages Vcc1 and Vcc2 supplied by the power amplifier 2, as described by the tracker circuit 1 of this embodiment. Figure 8 In the diagram, the horizontal axis represents time. The solid line represents the power supply voltage Vcc1 available in the first mode, and the dashed line represents the power supply voltage Vcc2 available in the second mode. Additionally, the envelope signal RF2 represents the envelope signal of the second high-frequency signal.

[0172] exist Figure 8In the first mode, three discrete voltages V4, V5, and V6 are used, which are higher than a predetermined voltage (e.g., the power supply voltage corresponding to the average power of the second high-frequency signal). In the second mode, two discrete voltages V5 and V6 are used, which are higher than a predetermined voltage.

[0173] In this situation, the power supply voltage Vcc1 available in the first mode, compared to the power supply voltage Vcc2 available in the second mode, allows the envelope signal RF2 of the second high-frequency signal to be tracked to a lower voltage. Therefore, in Figure 8 In this process, the first mode achieves higher power efficiency than the second mode. That is, when the PAPR of the high-frequency signal amplified by the power amplifier 2 is less than a threshold, applying the first mode to the switched capacitor circuit 20 can improve power efficiency.

[0174] also, Figure 7 and Figure 8 This is an exemplary implementation and is not intended to limit the combination of discrete voltages that can be supplied to power amplifier 2 in the first and second modes. Figure 7 and Figure 8 The diagram illustrates the periods during which three discrete voltages V4, V5, and V6 are supplied from a plurality of discrete voltages. However, other discrete voltages V1, V2, and V3 may also be supplied during other periods. In other words, the combination of discrete voltages supplied to power amplifier 2 is not limited to... Figure 7 and Figure 8 Examples.

[0175] Furthermore, the relationship between PAPR and the first and second modes is not limited to the above. For example, when PAPR is above a threshold, the first mode, which can generate more discrete voltages, can be applied to the switched capacitor circuit 20; when PAPR is below the threshold, the second mode, which can generate fewer discrete voltages, can be applied to the switched capacitor circuit 20.

[0176] Alternatively, the first mode and the second mode can be switched based on the modulation method of the high-frequency signal. For example, if the bit rate of the high-frequency signal modulation method is above a threshold, the second mode, which generates fewer discrete voltages, can be applied to the switched capacitor circuit 20; if the bit rate of the high-frequency signal modulation method is below the threshold, the first mode, which generates more discrete voltages, can be applied to the switched capacitor circuit 20. Conversely, the first mode can be applied to the switched capacitor circuit 20 if the bit rate of the high-frequency signal modulation method is above the threshold, and the second mode can be applied to the switched capacitor circuit 20 if the bit rate of the high-frequency signal modulation method is below the threshold.

[0177] The bit rate of a high-frequency signal modulation scheme can be determined by measuring the constellation points of the high-frequency signal. A higher bit rate results in a greater number of separable constellation points. Generally, QAM (Quadrature Amplitude Modulation) (e.g., 256QAM, 64QAM, 16QAM, etc.) has a higher bit rate and larger PAPR compared to PSK (Phase Shift Keying) (e.g., QPSK (Quadrature Phase Shift Keying), BPSK (Binary Phase Shift Keying), etc.).

[0178] [1.6 Summary]

[0179] As described above, the tracker circuit 1 of this embodiment includes: a switched capacitor circuit 20 configured to generate a plurality of discrete voltages based on an input voltage; and a power modulation circuit 30 configured to selectively output at least one of the generated discrete voltages to a power amplifier 2. The switched capacitor circuit 20 includes flying capacitors C200, C201, C202, and C203, smoothing capacitors C210, C211, and C212, and switches S200, S201, S202, S203, S204, S205, S206, S207, S208, S209, S210, S211, S224, and S225. One end of switch S200 and one end of switch S201 are connected to... One end of switch S202 and one end of switch S203 are connected to one of the two electrodes of flying capacitor C201. One end of switch S204 and one end of switch S205 are switchably connected to the other electrode of flying capacitor C200 via switch S224, and also to one of the two electrodes of flying capacitor C202. One end of switch S206 and one end of switch S207 are switchably connected to the other electrode of flying capacitor C201 via switch S225, and also to one of the two electrodes of flying capacitor C203. One end of switch S208 and one end of switch S209 are connected to one of the two electrodes of flying capacitor C201. One end of S209 is connected to the other electrode of the flying capacitor C202; one end of switch S210 and one end of switch S211 are connected to the other electrode of the flying capacitor C203; the other ends of switch S200, switch S202, and one electrode of the smoothing capacitor C210 are connected to ground; the other ends of switch S201, switch S203, switch S204, and switch S206 are connected to the other electrode of the smoothing capacitor C210 and one electrode of the smoothing capacitor C211; the other ends of switch S205, switch S207, and switch S208... The other end of switch S209 and the other end of switch S210 are connected to the other electrode of the two electrodes of smoothing capacitor C211 and one electrode of the two electrodes of smoothing capacitor C212. The other end of switch S209 and the other end of switch S211 are connected to the other electrode of the two electrodes of smoothing capacitor C212. One end of switch S224 is connected to the other electrode of the two electrodes of flying capacitor C200. The other end of switch S224 is connected to one electrode of the two electrodes of flying capacitor C202. One end of switch S225 is connected to the other electrode of the two electrodes of flying capacitor C201. The other end of switch S225 is connected to one electrode of the two electrodes of flying capacitor C203.

[0180] Therefore, the connection between flying capacitors C200 and C202 can be disconnected via switch S224, and the connection between flying capacitors C201 and C203 can be disconnected via switch S225. Thus, the operation of flying capacitors C200 and C201 can be switched in and out of the switching capacitor circuit 20. As a result, the number of discrete voltages that can be generated by the switching capacitor circuit 20 can be increased. Therefore, multiple discrete voltages more suitable for high-frequency signals amplified by the power amplifier 2 can be generated, improving power efficiency in D-ET mode.

[0181] For example, in the tracker circuit 1 of this embodiment, when the PAPR of the high-frequency signal amplified by the power amplifier 2 is less than a threshold, S224 and switch S225 can remain closed, and when the PAPR is above the threshold, switches S200, S201, S202 and S203 can remain closed, while switches S224 and S225 can remain open.

[0182] Therefore, the number of discrete voltages can be reduced even when the PAPR of the high-frequency signal amplified by power amplifier 2 is large. If the peak power of the high-frequency signals is the same, the average power of the high-frequency signal with a larger PAPR is lower than the average power of the high-frequency signal with a smaller PAPR. For example... Figure 7 As shown, when the number of available voltages in D-ET mode is limited, the fewer the number of discrete voltages, the better the envelope signal of the high-frequency signal can be tracked to a lower voltage. Therefore, by reducing the number of discrete voltages when the PAPR of the high-frequency signal amplified by power amplifier 2 is high, power efficiency in D-ET mode can be improved.

[0183] In addition, the tracker circuit 1 of this embodiment includes: a switched capacitor circuit 20 having a first mode for generating a plurality of first discrete voltages based on an input voltage and a second mode for generating a plurality of second discrete voltages based on an input voltage; and a power modulation circuit 30 configured to selectively output at least one of the generated plurality of first discrete voltages or a plurality of second discrete voltages to a power amplifier 2, wherein the number of the plurality of first discrete voltages is greater than the number of the plurality of second discrete voltages.

[0184] Therefore, the number of discrete voltages generated by the switched capacitor circuit 20 can be switched. Thus, multiple discrete voltages more suitable for the high-frequency signal amplified by the power amplifier 2 can be generated, improving power efficiency in D-ET mode.

[0185] (A variation of Implementation Method 1)

[0186] Furthermore, the switched capacitor circuit 20 of Embodiment 1 includes a switch S224 for disconnecting the flying capacitor C200 and flying capacitor C202 and a switch S225 for disconnecting the flying capacitor C201 and flying capacitor C203, but may also include a switch for disconnecting two other flying capacitors.

[0187] For example, such as Figure 9 As shown, the switched capacitor circuit 20B of this modified example may also include a switch S230 for disconnecting the flying capacitors C202 and C204, and a switch S231 for disconnecting the flying capacitors C203 and C205. Here, switches S230 and S231 are examples of the nineteenth and twentieth switches, respectively.

[0188] In this case, in addition to the first and second modes mentioned above, the switched capacitor circuit 20B can also achieve a third mode that generates four discrete voltages V3, V4, V5 and V6.

[0189] In the first stage of the third mode, switches S208, S211, S212, S215, S216, S219, S220, and S223 are closed, and switches S209, S210, S213, S214, S217, S218, S221, and S222 are open. Furthermore, switches S200, S201, S202, S203, S204, S205, S206, and S207 are closed, and switches S224, S225, S230, and S231 are open.

[0190] In the second phase of the third mode, switches S208, S211, S212, S215, S216, S219, S220, and S223 are open, while switches S209, S210, S213, S214, S217, S218, S221, and S222 are closed. Furthermore, switches S200, S201, S202, S203, S204, S205, S206, and S207 are closed, while switches S224, S225, S230, and S231 are open.

[0191] In the third mode, the fifth and sixth sets of switches switch on and off in the first and second stages. On the other hand, switches S200, S201, S202, S203, S204, S205, S206, and S207 remain closed in the first and second stages, while switches S224, S225, S230, and S231 remain open in the first and second stages.

[0192] Therefore, the switched capacitor circuit 20B can maintain multiple discrete voltages V3, V4, V5, and V6 at the four nodes N3, N4, N5, and N6 marked V3, V4, V5, and V6, satisfying (V6-V5):(V5-V4):(V4-V3):(V3-VG) = 1:1:1:1. For example, when the adjustment voltage Vcnv supplied from the pre-regulator circuit 10 is 5V, the switched capacitor circuit 20B can generate (1.67V, 3.33V, 5V, 6.67V) as four discrete voltages (V3, V4, V5, V6) in the third mode.

[0193] And, as Figure 9 As shown, the switched capacitor circuit 20B may also include a switch S232 for disconnecting the flying capacitors C204 and C206 and a switch S233 for disconnecting the flying capacitors C205 and C207.

[0194] In this case, in addition to the first, second, and third modes mentioned above, the switched capacitor circuit 20B can also achieve a fourth mode that generates three discrete voltages V4, V5, and V6.

[0195] In the first stage of the fourth mode, switches S212, S215, S216, S219, S220, and S223 are closed, and switches S213, S214, S217, S218, S221, and S222 are open. Furthermore, switches S200, S201, S202, S203, S204, S205, S206, S207, S208, S209, S210, and S211 are closed, and switches S224, S225, S230, S231, S232, and S233 are open.

[0196] In the second phase of the fourth mode, switches S212, S215, S216, S219, S220, and S223 are open, and switches S213, S214, S217, S218, S221, and S222 are closed. Furthermore, switches S200, S201, S202, S203, S204, S205, S206, S207, S208, S209, S210, and S211 are closed, while switches S224, S225, S230, S231, S232, and S233 are open.

[0197] In the fourth mode, the seventh and eighth sets of switches switch on and off in the first and second stages. On the other hand, switches S200, S201, S202, S203, S204, S205, S206, S207, S208, S209, S210, and S211 remain closed in the first and second stages, while switches S224, S225, S230, S231, S232, and S233 remain open in the first and second stages.

[0198] Therefore, the switched capacitor circuit 20B can maintain multiple discrete voltages V4, V5, and V6 at the three nodes N4, N5, and N6 marked V4, V5, and V6, satisfying (V6-V5):(V5-V4):(V4-VG) = 1:1:1. For example, when the adjustment voltage Vcnv supplied from the pre-regulator circuit 10 is 5V, the switched capacitor circuit 20B can generate (2.5V, 5V, 7.5V) as three discrete voltages (V4, V5, V6) in the fourth mode.

[0199] And, as Figure 9 As shown, the switched capacitor circuit 20B may also include a switch S234 for disconnecting the flying capacitors C206 and C208 and a switch S235 for disconnecting the flying capacitors C207 and C209.

[0200] In this case, in addition to the first, second, third and fourth modes mentioned above, the switched capacitor circuit 20B can also achieve a fifth mode that generates two discrete voltages V5 and V6.

[0201] In the first stage of the fifth mode, switches S216, S219, S220, and S223 in the ninth group are closed, and switches S217, S218, S221, and S222 in the tenth group are open. Furthermore, switches S200, S201, S202, S203, S204, S205, S206, S207, S208, S209, S210, S211, S212, S213, S214, and S215 are closed, and switches S224, S225, S230, S231, S232, S233, S234, and S235 are open.

[0202] In the second phase of the fifth mode, switches S216, S219, S220, and S223 in the ninth group are open, and switches S217, S218, S221, and S222 in the tenth group are closed. Furthermore, switches S200, S201, S202, S203, S204, S205, S206, S207, S208, S209, S210, S211, S212, S213, S214, and S215 are closed, while switches S224, S225, S230, S231, S232, S233, S234, and S235 are open.

[0203] In the fifth mode, the ninth and tenth switches switch on and off in the first and second stages. On the other hand, switches S200, S201, S202, S203, S204, S205, S206, S207, S208, S209, S210, S211, S212, S213, S214, and S215 remain closed in the first and second stages, while switches S224, S225, S230, S231, S232, S233, S234, and S235 remain open in the first and second stages.

[0204] Therefore, the switched capacitor circuit 20B can maintain multiple discrete voltages V5 and V6 at the two nodes N5 and N6 marked V5 and V6, satisfying (V6-V5):(V5-VG) = 1:1. For example, when the adjustment voltage Vcnv supplied from the pre-regulator circuit 10 is 5V, the switched capacitor circuit 20B can generate (5V, 10V) as two discrete voltages (V5, V6) in the fifth mode.

[0205] As described above, in the tracker circuit 1 of this modified example, the switched capacitor circuit 20B further includes flying capacitors C204 and C205, a smoothing capacitor C212, and switches S212, S213, S214, S215, S230, and S231. One end of switch S208 and one end of switch S209 are switchably connected to the other electrode of the two electrodes of flying capacitor C202 via switch S230, and to one electrode of the two electrodes of flying capacitor C204. One end of switch S210 and one end of switch S211 are switchably connected to the other electrode of the two electrodes of flying capacitor C203 via switch S231, and to one electrode of the two electrodes of flying capacitor C205. One end of switch S212 and one end of switch S213 are connected to the other electrode of the two electrodes of flying capacitor C204, and one end of switch S214... And one end of switch S215 is connected to the other electrode of the two electrodes of flying capacitor C205; the other ends of switch S209, switch S211, switch S212 and switch S214 are connected to the other electrode of the two electrodes of smoothing capacitor C212 and one electrode of the two electrodes of smoothing capacitor C213; the other ends of switch S213 and switch S215 are connected to the other electrode of the two electrodes of smoothing capacitor C213; one end of switch S230 is connected to the other electrode of the two electrodes of flying capacitor C202; the other end of switch S230 is connected to one electrode of the two electrodes of flying capacitor C204; one end of switch S231 is connected to the other electrode of the two electrodes of flying capacitor C203; the other end of switch S231 is connected to one electrode of the two electrodes of flying capacitor C205.

[0206] Therefore, the connection between flying capacitors C202 and C204 can be disconnected via switch S230, and the connection between flying capacitors C203 and C205 can be disconnected via switch S231. Thus, the flying capacitors C202 and C203 can be switched to function / not function within the switched capacitor circuit 20B. As a result, the number of discrete voltages that can be generated by the switched capacitor circuit 20B can be further increased. Therefore, multiple discrete voltages more suitable for high-frequency signals amplified by the power amplifier 2 can be generated, further improving power efficiency in D-ET mode.

[0207] (Implementation Method 2)

[0208] Next, Embodiment 2 will be described. In this embodiment, the main difference is in the circuit structure of the switched capacitor circuit compared to Embodiment 1. Hereinafter, this embodiment will be described with reference to the accompanying drawings, focusing on the differences from Embodiment 1.

[0209] [2.1 Circuit structure of communication device 7A and tracker circuit 1A]

[0210] First, refer to Figure 10 The circuit structure of the communication device 7A in this embodiment will be described. Figure 10 This is a circuit structure diagram of the communication device 7A according to this embodiment.

[0211] also, Figure 10 This is an exemplary circuit structure, and the communication device 7A can be installed using various circuit mountings and any of the circuit technologies available. Therefore, the following description of the communication device 7A should not be interpreted limitingly.

[0212] The communication device 7A is identical to the tracker circuit 1 in Embodiment 1, except that it replaces the tracker circuit 1 and includes the tracker circuit 1A. Therefore, the description of the communication device 7A is omitted except for the description of the tracker circuit 1A.

[0213] Tracker circuit 1A can supply power voltage Vcc to power amplifier 2 in D-ET mode. Furthermore, tracker circuit 1A can also supply power voltage Vcc to power amplifier 2 in APT mode. Figure 2 As shown, the tracker circuit 1A includes a pre-regulator circuit 10, a switched capacitor circuit 20A, a power modulation circuit 30, an input terminal 41, an output terminal 42, and a digital control circuit 60.

[0214] In other words, tracker circuit 1A is the same as tracker circuit 1 in Embodiment 1, except that it has the switching capacitor circuit 20A instead of the switching capacitor circuit 20. Therefore, the description of tracker circuit 1A is omitted except for the description of switching capacitor circuit 20A.

[0215] The switched capacitor circuit 20A can generate multiple discrete voltages V1, V2, V3, V4, V5, and V6, or V1, V3, V4, V5, and V6, based on the adjustment voltage Vcnv supplied by the pre-regulator circuit 10. Specifically, the switched capacitor circuit 20A has a first mode that generates multiple discrete voltages V1, V2, V3, V4, V5, and V6 (an example of multiple first discrete voltages) based on the adjustment voltage Vcnv, and a second mode that generates multiple discrete voltages V1, V3, V4, V5, and V6 (an example of multiple second discrete voltages) based on the adjustment voltage Vcnv. In this case, the number of discrete voltages V1, V2, V3, V4, V5, and V6 generated in the first mode is greater than the number of discrete voltages V1, V3, V4, V5, and V6 generated in the second mode. For a detailed circuit structure of the switched capacitor circuit 20A, use... Figure 11To be discussed later.

[0216] [2.2 Circuit structure of the 20A switched capacitor circuit]

[0217] Reference Figure 11 The circuit structure of the 20A switched capacitor circuit is described. Figure 11 This is a circuit diagram of the switched capacitor circuit 20A in this embodiment.

[0218] also, Figure 11 This is an exemplary circuit structure, and the switched capacitor circuit 20A can be installed using various circuit mountings and any of the circuit techniques employed. Therefore, the following description of the switched capacitor circuit 20A should not be interpreted in a limiting sense.

[0219] The switched capacitor circuit 20A has a ladder-shaped circuit structure and can generate multiple discrete voltages V1, V2, V3, V4, V5, and V6, or V1, V3, V4, V5, and V6. Specifically, the switched capacitor circuit 20A includes flying capacitors C200 to C209, smoothing capacitors C210 to C215, switches S200 to S223 and S226 to S228, input terminal T200, and output terminals T201 to T206. Energy and charge are input from the pre-regulator circuit 10 to node N5 via input terminal T200, and are led out from nodes N1, N2, N3, N4, N5, and N6 to power modulation circuit 30 via output terminals T201, T202, T203, T204, T205, and T206.

[0220] In this embodiment, flying capacitors C202, C203, C204, and C205 are examples of a first flying capacitor, a second flying capacitor, a third flying capacitor, and a fourth flying capacitor, respectively. Similarly, smoothing capacitors C211, C212, and C213 are examples of a first smoothing capacitor, a second smoothing capacitor, and a third smoothing capacitor, respectively. Furthermore, switches S204, S205, S206, S207, S208, S209, S210, S211, S212, S213, S214, and S215 are examples of a first switch, a second switch, a third switch, a fourth switch, a fifth switch, a sixth switch, a seventh switch, an eighth switch, a ninth switch, a tenth switch, an eleventh switch, and a twelfth switch, respectively.

[0221] Switch S226 is an example of a thirteenth switch, connected between the two electrodes of smoothing capacitor C212. Specifically, one end of switch S226 is connected to one of the two electrodes of smoothing capacitor C212. On the other hand, the other end of switch S226 is connected to the other electrode of smoothing capacitor C212. When switch S226 is closed, the two electrodes of smoothing capacitor C212 are short-circuited.

[0222] Switch S227 is an example of the fourteenth switch, connected between the two electrodes of the flying capacitor C202. Specifically, one end of switch S227 is connected to one of the two electrodes of the flying capacitor C202. On the other hand, the other end of switch S227 is connected to the other electrode of the flying capacitor C202. When switch S227 is closed, the two electrodes of the flying capacitor C202 are short-circuited. Furthermore, switch S227 is arbitrary and may not be included in the switched capacitor circuit 20A.

[0223] Switch S228 is an example of the fifteenth switch, connected between the two electrodes of the flying capacitor C203. Specifically, one end of switch S228 is connected to one of the two electrodes of the flying capacitor C203. On the other hand, the other end of switch S228 is connected to the other electrode of the flying capacitor C203. When switch S228 is closed, the two electrodes of the flying capacitor C203 are short-circuited. Furthermore, switch S228 is arbitrary and may not be included in the switched capacitor circuit 20A.

[0224] [2.3 Control method for 20A switched capacitor circuit]

[0225] Next, refer to Figure 12A , Figure 12B , Figure 13A as well as Figure 13B The control method of the switched capacitor circuit 20A in this embodiment will be described.

[0226] [2.3.1 First Mode]

[0227] First, refer to Figure 12A and Figure 12B The first mode will be explained. Figure 12A This is a circuit structure diagram showing the connection state in the first stage of the first mode of the switched capacitor circuit 20A in this embodiment. Figure 12B This is a circuit structure diagram showing the connection state in the second stage of the first mode of the switched capacitor circuit 20A in this embodiment.

[0228] The first mode is used by the switched capacitor circuit 20A to generate six discrete voltages V1, V2, V3, V4, V5, and V6. In other words, in the first mode, the switched capacitor circuit 20A constitutes a 6-stage switched capacitor.

[0229] In the first mode, the first and second stages alternately repeat based on the control signal CS20 from the digital control circuit 60.

[0230] In the first phase of the first mode, such as Figure 12A As shown, the first set of switches S200, S203, S204, S207, S208, S211, S212, S215, S216, S219, S220, and S223 are closed, and the second set of switches S201, S202, S205, S206, S209, S210, S213, S214, S217, S218, S221, and S222 are open. Furthermore, switches S226, S227, and S228 are open.

[0231] In the second phase of the first mode, such as Figure 12B As shown, the first set of switches S200, S203, S204, S207, S208, S211, S212, S215, S216, S219, S220, and S223 are open, and the second set of switches S201, S202, S205, S206, S209, S210, S213, S214, S217, S218, S221, and S222 are closed. Furthermore, switches S226, S227, and S228 are open.

[0232] In this first mode, the first set of switches and the second set of switches switch on and off in the first and second stages. On the other hand, switches S226, S227, and S228 remain off in the first and second stages.

[0233] By repeating this first and second stage, the flying capacitors C200, C201, C202, C203, C204, C205, C206, C207, C208, and C209 can be charged and discharged complementaryly. For example, in one of the first and second stages, charging of the smoothing capacitors C210, C211, C212, C213, C214, and C215 is performed from the flying capacitors C200, C202, C204, C206, and C208; and in the other of the first and second stages, charging of the smoothing capacitors C210, C211, C212, C213, C214, and C215 is performed from the flying capacitors C201, C203, C205, C207, and C209. In other words, since the smoothing capacitors C210, C211, C212, C213, C214, and C215 are always charged by any one of the flying capacitors C200, C201, C202, C203, C204, C205, C206, C207, C208, and C209, even if the current flows at high speed from any one of nodes N1, N2, N3, N4, N5, and N6 to the power modulation circuit 30, the charge will be replenished at high speed to any one of nodes N1, N2, N3, N4, N5, and N6, thus suppressing the potential changes of nodes N1, N2, N3, N4, N5, and N6.

[0234] Through this operation, the switched capacitor circuit 20A can maintain nearly equal voltages across the smoothing capacitors C210, C211, C212, C213, C214, and C215. Specifically, at the six nodes N1, N2, N3, N4, N5, and N6, labeled V1, V2, V3, V4, V5, and V6, multiple discrete voltages V1, V2, V3, V4, V5, and V6 are maintained, satisfying (V6-V5):(V5-V4):(V4-V3):(V3-V2):(V2-V1):(V1-VG)=1:1:1:1:1:1. For example, when the adjustment voltage Vcnv supplied from the pre-regulator circuit 10 is 5V, the switched capacitor circuit 20A can generate (1V, 2V, 3V, 4V, 5V, 6V) as 6 discrete voltages (V1, V2, V3, V4, V5, V6).

[0235] [2.3.2 Second Mode]

[0236] Next, refer to Figure 13A and Figure 13B The second mode will be explained. Figure 13A This is a circuit structure diagram showing the connection state in the first stage of the second mode of the switched capacitor circuit 20A in this embodiment. Figure 13BThis is a circuit structure diagram showing the connection state in the second stage of the second mode of the switched capacitor circuit 20A in this embodiment.

[0237] The second mode is used by the switched capacitor circuit 20A to generate five discrete voltages V1, V3, V4, V5, and V6. In other words, in the second mode, the switched capacitor circuit 20A constitutes a 5-stage switched capacitor.

[0238] In the second mode, the first and second stages are repeated alternately based on the control signal CS20 from the digital control circuit 60.

[0239] In the first phase of the second mode, such as Figure 13A As shown, the third group of switches S200, S203, S204, S207, S212, S215, S216, S219, S220, and S223 are closed, and the fourth group of switches S201, S202, S205, S206, S213, S214, S217, S218, S221, and S222 are open. Furthermore, switches S208, S209, S210, and S211 are open, and switches S226, S227, and S228 are closed.

[0240] In the second phase of the second mode, such as Figure 13B As shown, the third group of switches S200, S203, S204, S207, S212, S215, S216, S219, S220, and S223 are open, and the fourth group of switches S201, S202, S205, S206, S213, S214, S217, S218, S221, and S222 are closed. Furthermore, switches S208, S209, S210, and S211 are open, and switches S226, S227, and S228 are closed.

[0241] In this second mode, the third and fourth sets of switches switch on and off in the first and second stages. On the other hand, switches S208, S209, S210, and S211 remain open in the first and second stages, while switches S226, S227, and S228 remain closed in the first and second stages.

[0242] By repeating this first and second stage, the flying capacitors C200, C201, C204, C205, C206, C207, C208, and C209 can be charged and discharged complementaryly. For example, in one of the first and second stages, the smoothing capacitors C210, C211, C213, C214, and C215 are charged from the flying capacitors C200, C204, C206, and C208; and in the other of the first and second stages, the smoothing capacitors C210, C211, C213, C214, and C215 are charged from the flying capacitors C201, C205, C207, and C209. In other words, since the smoothing capacitors C210, C211, C213, C214, and C215 are always charged by any one of the flying capacitors C200, C201, C204, C205, C206, C207, C208, and C209, even if the current flows at high speed from any one of nodes N1, N3, N4, N5, and N6 to the power modulation circuit 30, the charge can be replenished at high speed to any one of nodes N1, N3, N4, N5, and N6, thereby suppressing the potential changes of nodes N1, N3, N4, N5, and N6.

[0243] Through this operation, the switched capacitor circuit 20A can maintain nearly equal voltages across the smoothing capacitors C210, C211, C213, C214, and C215. Specifically, at the five nodes N1, N3, N4, N5, and N6, labeled V1, V3, V4, V5, and V6, multiple discrete voltages V1, V3 (= V2), V4, V5, and V6 are maintained, satisfying (V6-V5):(V5-V4):(V4-V3):(V3-V1):(V1-VG) = 1:1:1:1:1. For example, when the adjustment voltage Vcnv supplied from the pre-regulator circuit 10 is 5V, the switched capacitor circuit 20A can generate (1.25V, 2.5V, 3.75V, 5V, 6.25V) as five discrete voltages (V1, V3, V4, V5, V6).

[0244] [2.4 Multiple discrete voltages generated in the first mode and the second mode]

[0245] Next, refer to Figure 14 The multiple discrete voltages generated by the switched capacitor circuit 20A of this embodiment will be explained. Figure 14 This is a diagram illustrating an example of multiple discrete voltages generated by the switched capacitor circuit 20A in this embodiment. Furthermore, in Figure 14 In this context, the power supply voltage Vcc corresponding to the peak power of the high-frequency signal amplified by power amplifier 2 is 6V.

[0246] For example, in the first mode, a 5V adjustment voltage Vcnv is supplied from the pre-regulator circuit 10 to the switched capacitor circuit 20A. In this case, the switched capacitor circuit 20A can generate six discrete voltages (1V, 2V, 3V, 4V, 5V, 6V).

[0247] For example, in the second mode, a 4.8V adjustment voltage Vcnv is supplied from the pre-regulator circuit 10 to the switched capacitor circuit 20A. In this case, the switched capacitor circuit 20A can generate five discrete voltages (1.2V, 2.4V, 3.6V, 4.8V, 6V).

[0248] Furthermore, in this embodiment, similar to Embodiment 1, by applying the second mode to the switched capacitor circuit 20A when the PAPR of the high-frequency signal is above a threshold, and applying the first mode to the switched capacitor circuit 20A when the PAPR of the high-frequency signal is below a threshold, power efficiency can be improved.

[0249] [2.5 Summary]

[0250] As described above, the tracker circuit 1A of this embodiment includes: a switched capacitor circuit 20A configured to generate a plurality of discrete voltages based on the input voltage; and a power modulation circuit 30 configured to selectively output at least one of the generated plurality of discrete voltages to the power amplifier 2. The switched capacitor circuit 20A includes flying capacitors C202, C203, C204 and C205, smoothing capacitors C211, C212 and C213, and switches S204, S205, S206, S207, S208, S209, S210, S211, S212, S213, S214, S215 and S216. 226. One end of switch S204 and one end of switch S205 are connected to one of the two electrodes of the flying capacitor C202; one end of switch S206 and one end of switch S207 are connected to one of the two electrodes of the flying capacitor C203; one end of switch S208 and one end of switch S209 are connected to the other electrode of the flying capacitor C202 and one of the two electrodes of the flying capacitor C204; one end of switch S210 and one end of switch S211 are connected to the other electrode of the flying capacitor C203 and both electrodes of the flying capacitor C205. One electrode of the electrode, one end of switch S212 and one end of switch S213 are connected to the other electrode of the flying capacitor C204; one end of switch S214 and one end of switch S215 are connected to the other electrode of the flying capacitor C205; the other end of switch S204, the other end of switch S206, and one electrode of the smoothing capacitor C211 are interconnected; the other ends of switch S205, the other ends of switch S207, the other ends of switch S208, and the other ends of switch S210 are connected to the other electrode of the smoothing capacitor C211. One of the two electrodes of smoothing capacitor C212, the other end of switch S209, the other end of switch S211, the other end of switch S212, and the other end of switch S214 are connected to the other electrode of smoothing capacitor C212 and one of the two electrodes of smoothing capacitor C213. The other end of switch S213 and the other end of switch S215 are connected to the other electrode of smoothing capacitor C213. One end and the other end of switch S226 are respectively connected to one and the other electrode of smoothing capacitor C211, C212, or C213.

[0251] Therefore, the smoothing capacitors C211, C212, or C213 can be short-circuited via switch S226. Thus, the smoothing capacitors C211, C212, or C213 can be switched to function or not function within the switched capacitor circuit 20A. As a result, the number of discrete voltages that can be generated by the switched capacitor circuit 20A can be increased. This allows for the generation of multiple discrete voltages more suitable for the high-frequency signal amplified by the power amplifier 2, improving power efficiency in D-ET mode.

[0252] Alternatively, in the tracker circuit 1A of this embodiment, one end of switch S226 and the other end can be connected to one electrode and the other electrode of the smoothing capacitor C212, respectively. When the PAPR of the high-frequency signal amplified by the power amplifier 2 is less than the threshold, switch S226 can be kept in the open state. When the PAPR is above the threshold, switches S208, S209, S210 and S211 can be kept in the open state, and switch S226 can be kept in the closed state.

[0253] Therefore, when the PAPR of the high-frequency signal amplified by power amplifier 2 is large, the number of discrete voltages can be reduced. If the peak power of the high-frequency signals is the same, the average power of the high-frequency signal with a larger PAPR is lower than the average power of the high-frequency signal with a smaller PAPR. Figure 7 As shown, when the number of available voltages is limited in D-ET mode, the fewer the number of discrete voltages, the better the envelope signal of the high-frequency signal can be tracked to a lower voltage. Therefore, when the PAPR of the high-frequency signal amplified by power amplifier 2 is high, reducing the number of discrete voltages can improve power efficiency in D-ET mode.

[0254] For example, in the tracker circuit 1A of this embodiment, the switched capacitor circuit 20A may also include switches S227 and S228. One end of switch S226 and the other end may be connected to one electrode and the other electrode of the smoothing capacitor C212, respectively. One end of switch S227 and the other end may be connected to one electrode and the other electrode of the flying capacitor C202, respectively. One end of switch S228 and the other end may be connected to one electrode and the other electrode of the flying capacitor C203, respectively.

[0255] Therefore, the flying capacitor C202 can be short-circuited via switch S227, and the flying capacitor C203 can be short-circuited via switch S228. Thus, by closing switches S227 and S228 when switch S226 is closed, the series connection between flying capacitors C204 and C202 can be broken, and the series connection between flying capacitors C205 and C203 can also be broken. As a result, the decrease in capacitance of the flying capacitors can be suppressed, and fluctuations in the voltage supplied by the switched capacitor circuit 20A can be suppressed.

[0256] For example, in the tracker circuit 1A of this embodiment, when the PAPR of the high-frequency signal amplified by the power amplifier 2 is less than the threshold, switches S226, S227 and S228 may be kept in the open state. When the PAPR is above the threshold, switches S208, S209, S210 and S211 may be kept in the open state, and switches S226, S227 and S228 may be kept in the closed state.

[0257] Therefore, when the PAPR of the high-frequency signal amplified by power amplifier 2 is large, the number of discrete voltages can be reduced. If the peak power of the high-frequency signals is the same, the average power of the high-frequency signal with a larger PAPR is lower than the average power of the high-frequency signal with a smaller PAPR. For example... Figure 7 As shown, when the number of available voltages in D-ET mode is limited, the fewer the number of discrete voltages, the better the envelope signal of the high-frequency signal can be tracked to a lower voltage. Therefore, when the PAPR of the high-frequency signal amplified by power amplifier 2 is high, reducing the number of discrete voltages can improve power efficiency in D-ET mode.

[0258] In addition, the tracker circuit 1A of this embodiment includes: a switched capacitor circuit 20A having a first mode and a second mode, wherein in the first mode a plurality of first discrete voltages are generated based on the input voltage, and in the second mode a plurality of second discrete voltages are generated based on the input voltage; and a power modulation circuit 30 configured to selectively output at least one of the generated plurality of first discrete voltages or plurality of second discrete voltages to a power amplifier 2, wherein the number of the plurality of first discrete voltages is greater than the number of the plurality of second discrete voltages.

[0259] Therefore, it is possible to switch the number of discrete voltages generated by the switched capacitor circuit 20A. Thus, it is possible to generate multiple discrete voltages more suitable for the high-frequency signal amplified by the power amplifier 2, thereby improving power efficiency in D-ET mode.

[0260] (A variation of Implementation Method 2)

[0261] Furthermore, the switched capacitor circuit 20A of Embodiment 2 includes a switch S226 for short-circuiting the smoothing capacitor C212, but it may also replace the switch S226 or include a switch for short-circuiting the smoothing capacitors C210, C211, C213, C214 or C215, or any combination thereof, respectively, based on the switch S226.

[0262] For example, such as Figure 15 As shown, the switched capacitor circuit 20C of this modified example may also include a switch S242 for short-circuiting the smoothing capacitor C213, and may also include switches S247 and S248 for short-circuiting the flying capacitors C204 and C205 respectively.

[0263] Switch S242 is an example of the sixteenth switch, connected between the two electrodes of smoothing capacitor C213. Specifically, one end of switch S242 is connected to one of the two electrodes of smoothing capacitor C213. On the other hand, the other end of switch S242 is connected to the other electrode of smoothing capacitor C213. By closing switch S242, the two electrodes of smoothing capacitor C213 are short-circuited.

[0264] Switch S247 is an example of the seventeenth switch, connected between the two electrodes of the flying capacitor C204. Specifically, one end of switch S247 is connected to one of the two electrodes of the flying capacitor C204. On the other hand, the other end of switch S247 is connected to the other electrode of the flying capacitor C204. By closing switch S247, the two electrodes of the flying capacitor C204 are short-circuited. Furthermore, switch S247 is arbitrary and may not be included in the switched capacitor circuit 20C.

[0265] Switch S248 is an example of the eighteenth switch, connected between the two electrodes of the flying capacitor C205. Specifically, one end of switch S248 is connected to one of the two electrodes of the flying capacitor C205. On the other hand, the other end of switch S248 is connected to the other electrode of the flying capacitor C205. By closing switch S248, the two electrodes of the flying capacitor C205 are short-circuited. Furthermore, switch S248 is arbitrary and may not be included in the switched capacitor circuit 20C.

[0266] In the second mode described above, for example, switches S212, S213, S214, and S215 can be kept open in the first and second stages instead of switches S208, S209, S210, and S211, and switches S242, S247, and S248 can be kept closed in the first and second stages instead of switches S226, S227, and S228. Thus, the switched capacitor circuit 20C can generate five discrete voltages V1, V2, V4 (=V3), V5, and V6.

[0267] Furthermore, in addition to the first and second modes mentioned above, the switched capacitor circuit 20C can also achieve a third mode that generates four discrete voltages V1, V4, V5, and V6.

[0268] In the first stage of the third mode, for example, the fifth group of switches S200, S203, S204, S207, S216, S219, S220, and S223 are closed, and the sixth group of switches S201, S202, S205, S206, S217, S218, S221, and S222 are open. Furthermore, switches S208, S209, S210, S211, S212, S213, S214, and S215 are open, and switches S226, S227, S228, S242, S247, and S248 are closed.

[0269] In the second stage of the third mode, for example, the fifth group of switches S200, S203, S204, S207, S216, S219, S220, and S223 are open, and the sixth group of switches S201, S202, S205, S206, S217, S218, S221, and S222 are closed. Furthermore, switches S208, S209, S210, S211, S212, S213, S214, and S215 are open, and switches S226, S227, S228, S242, S247, and S248 are closed.

[0270] In the third mode, the fifth and sixth sets of switches switch on and off in the first and second stages. On the other hand, switches S208, S209, S210, S211, S212, S213, S214, and S215 remain open in the first and second stages, while switches S226, S227, S228, S242, S247, and S248 remain closed in the first and second stages.

[0271] Therefore, the switched capacitor circuit 20C can maintain multiple discrete voltages V1, V4 (=V3=V2), V5, and V6 at the three nodes N1, N4, N5, and N6 marked with V1, V4, V5, and V6, satisfying (V6-V5):(V5-V4):(V4-V1):(V1-VG)=1:1:1:1. For example, when the adjustment voltage Vcnv supplied from the pre-regulator circuit 10 is 5V, the switched capacitor circuit 20C can generate (1.67V, 3.33V, 5V, 6.67V) as four discrete voltages (V1, V4, V5, V6) in the third mode.

[0272] In addition, such as Figure 15 As shown, the switched capacitor circuit 20C can also replace switch S242, or, based on switch S242, include switches S240, S241, S243, S244, or any combination thereof. Similarly, the switched capacitor circuit 20C can also replace a group of switches S247 and S248, or, based on a group of switches S247 and S248, include a group of switches S245 and S246, a group of switches S249 and S250, a group of switches S251 and S252, or any combination thereof.

[0273] As described above, in the tracker circuit 1A of this modified example, the switched capacitor circuit 20C also includes a switch S242, one end of which and the other end of which can be connected to one electrode and the other electrode of the smoothing capacitor C213, respectively.

[0274] Therefore, the smoothing capacitor C213 can be short-circuited by switch S242. Thus, in the switched capacitor circuit 20C, it is possible to switch the smoothing capacitor C213 to function / not function. As a result, the number of discrete voltages that can be generated by the switched capacitor circuit 20C can be increased. Therefore, multiple discrete voltages more suitable for the high-frequency signal amplified by the power amplifier 2 can be generated, improving power efficiency in D-ET mode.

[0275] For example, in the tracker circuit 1A of this modified example, the switched capacitor circuit 20C also includes switches S247 and S248. One end of switch S247 and the other end can be connected to one electrode and the other electrode of the flying capacitor C204, respectively. One end of switch S248 and the other end can also be connected to one electrode and the other electrode of the flying capacitor C205, respectively.

[0276] Therefore, the flying capacitor C204 can be short-circuited via switch S247, and the flying capacitor C205 can be short-circuited via switch S248. Thus, by closing switches S247 and S248 when switch S242 is closed, the series connection between flying capacitors C206 and C204 can be broken, and the series connection between flying capacitors C207 and C205 can be broken. As a result, the decrease in capacitance of the flying capacitors can be suppressed, and fluctuations in the voltage supplied by the switched capacitor circuit 20C can be suppressed.

[0277] (Other implementation methods)

[0278] The tracker circuit of the present invention has been described above based on the embodiments, but the tracker circuit of the present invention is not limited to the above embodiments. Other embodiments implemented by combining any of the constituent elements in the above embodiments, variations that can be conceived by those skilled in the art by implementing the above embodiments without departing from the spirit of the present invention, and various devices that incorporate the above tracker circuit are also included in the present invention.

[0279] For example, in the circuit structures of the various circuits in the above embodiments, other circuit elements and wiring may be inserted between the paths connecting the circuit elements and signal paths disclosed in the accompanying drawings. For example, an inductor and / or capacitor may be inserted between the tracker circuit and the power amplifier.

[0280] Furthermore, the connection relationship between the input terminal and the node can be changed in the switched capacitor circuits of the above embodiments. For example, in Embodiment 1 and / or Embodiment 2, the input terminal T200 can be connected to nodes N1, N2, N3, N4, or N6 instead of node N5. In this case, the same effect as in Embodiment 1 and / or Embodiment 2 can be obtained.

[0281] Furthermore, the tracker circuits in the above embodiments can also include multiple power modulation circuits. In this case, the tracker circuit can supply different voltages to multiple power amplifiers.

[0282] Furthermore, the switched capacitor circuits of the above embodiments have a circuit structure capable of generating up to 6 discrete voltages, but may also have a circuit structure capable of generating up to 3, 4, 5, or 7 or more discrete voltages. For example, in Embodiment 1, when the switched capacitor circuit 20 can generate up to 3 discrete voltages, the switched capacitor circuit 20 may not include flying capacitors C204 to C209, smoothing capacitors C213 to C215, and switches S212 to S223.

[0283] This invention, as a tracker circuit for supplying voltage to a power amplifier, can be widely used in communication devices such as mobile phones.

[0284] Explanation of reference numerals in the attached figures

[0285] 1 / 1A… Tracker circuit; 2… Power amplifier; 3… Filter; 5… RFIC; 6… Antenna; 7, 7A… Communication device; 10… Pre-conditioner circuit; 20, 20A, 20B, 20C… Switched capacitor circuit; 30… Power modulation circuit; 41, T101, T200, T301, T302, T303, T304, T305, T306… Input terminals; 42, T102, T201, T202, T203… T204, T205, T206, T307… Output terminals; 50… DC power supply; 60… Digital control circuit; 61… First controller; 62… Second controller; C101… Capacitor; C200, C201, C202, C203, C204, C205, C206, C207, C208, C209… Flying capacitors; C210, C211, C212, C213, C214, C215… Smoothing capacitors; CS10, CS20, CS30… control signals; L101… power inductor; S101, S102, S103, S104, S200, S201, S202, S203, S204, S205, S206, S207, S208, S209, S210, S211, S212, S213, S214, S215, S216, S217, S218, S219, S220, S221, S… Switches 222, S223, S224, S225, S226, S227, S228, S230, S231, S232, S233, S234, S235, S240, S241, S242, S243, S244, S245, S246, S247, S248, S249, S250, S251, S252, S301, S302, S303, S304, S305, S306…

Claims

1. A tracker circuit, comprising: A switched capacitor circuit is configured to generate multiple discrete voltages based on the input voltage; and The power supply modulation circuit is configured to selectively output at least one of the generated discrete voltages to a power amplifier. The above switched capacitor circuit includes: First flying capacitor, second flying capacitor, third flying capacitor and fourth flying capacitor; The first smoothing capacitor, the second smoothing capacitor, and the third smoothing capacitor; and First switch, second switch, third switch, fourth switch, fifth switch, sixth switch, seventh switch, eighth switch, ninth switch, tenth switch, eleventh switch, twelfth switch, thirteenth switch, and fourteenth switch. One end of the first switch and one end of the second switch are connected to one of the two electrodes of the first flying capacitor. One end of the third switch and one end of the fourth switch are connected to one of the two electrodes of the second flying capacitor. One end of the fifth switch and one end of the sixth switch are switchably connected to the other electrode of the first flying capacitor via the thirteenth switch, and also connected to one electrode of the third flying capacitor. One end of the seventh switch and one end of the eighth switch are switchably connected to the other electrode of the second flying capacitor via the fourteenth switch, and also connected to one electrode of the fourth flying capacitor. One end of the aforementioned ninth switch and one end of the aforementioned tenth switch are connected to the other electrode of the two electrodes of the aforementioned third flying capacitor. One end of the eleventh switch and one end of the twelfth switch are connected to the other electrode of the four flying capacitor. The other end of the first switch, the other end of the third switch, and one of the two electrodes of the first smoothing capacitor are connected to ground. The other ends of the second switch, the fourth switch, the fifth switch, and the seventh switch are connected to the other electrode of the first smoothing capacitor and one electrode of the second smoothing capacitor. The other ends of the sixth switch, the eighth switch, the ninth switch, and the eleventh switch are connected to the other electrode of the second smoothing capacitor and one electrode of the third smoothing capacitor. The other end of the tenth switch and the other end of the twelfth switch are connected to the other electrode of the third smoothing capacitor. One end of the aforementioned thirteenth switch is connected to the other electrode of the first flying capacitor. The other end of the aforementioned thirteenth switch is connected to one of the two electrodes of the aforementioned third flying capacitor. One end of the fourteenth switch is connected to the other electrode of the second flying capacitor. The other end of the fourteenth switch is connected to one of the two electrodes of the fourth flying capacitor.

2. The tracker circuit according to claim 1, wherein, When the PAPR (Peak to Average Power Ratio) of the high-frequency signal amplified by the aforementioned power amplifier is less than the threshold, the thirteenth and fourteenth switches remain closed. When the PAPR is above the threshold, the first switch, the second switch, the third switch, and the fourth switch remain closed, while the thirteenth switch and the fourteenth switch remain open.

3. The tracker circuit according to claim 1 or 2, wherein, The above-mentioned switched capacitor circuit also includes: The fifth and sixth flying capacitors; The fourth smoothing capacitor; and Switches 15, 16, 17, 18, 19, and 20. One end of the aforementioned ninth switch and one end of the aforementioned tenth switch are switchably connected to the other electrode of the two electrodes of the aforementioned third flying capacitor via the aforementioned nineteenth switch, and are also connected to one electrode of the two electrodes of the aforementioned fifth flying capacitor. One end of the eleventh switch and one end of the twelfth switch are switchably connected to the other electrode of the four flying capacitor via the twentieth switch, and also connected to one electrode of the six flying capacitor. One end of the aforementioned fifteenth switch and one end of the aforementioned sixteenth switch are connected to the other electrode of the two electrodes of the aforementioned fifth flying capacitor. One end of the aforementioned seventeenth switch and one end of the aforementioned eighteenth switch are connected to the other electrode of the two electrodes of the aforementioned sixth flying capacitor. The other end of the tenth switch, the other end of the twelfth switch, the other end of the fifteenth switch, and the other end of the seventeenth switch are connected to the other electrode of the third smoothing capacitor and one electrode of the fourth smoothing capacitor. The other end of the sixteenth switch and the other end of the eighteenth switch are connected to the other electrode of the fourth smoothing capacitor. One end of the aforementioned nineteenth switch is connected to the other electrode of the aforementioned third flying capacitor. The other end of the aforementioned nineteenth switch is connected to one of the two electrodes of the aforementioned fifth flying capacitor. One end of the aforementioned twentieth switch is connected to the other electrode of the aforementioned fourth flying capacitor. The other end of the twentieth switch is connected to one of the two electrodes of the sixth flying capacitor.

4. A tracker circuit, comprising: A switched capacitor circuit is configured to generate multiple discrete voltages based on the input voltage; and The power supply modulation circuit is configured to selectively output at least one of the generated discrete voltages to a power amplifier. The above switched capacitor circuit includes: First flying capacitor, second flying capacitor, third flying capacitor and fourth flying capacitor; The first smoothing capacitor, the second smoothing capacitor, and the third smoothing capacitor; and First switch, second switch, third switch, fourth switch, fifth switch, sixth switch, seventh switch, eighth switch, ninth switch, tenth switch, eleventh switch, twelfth switch, and thirteenth switch. One end of the first switch and one end of the second switch are connected to one of the two electrodes of the first flying capacitor. One end of the third switch and one end of the fourth switch are connected to one of the two electrodes of the second flying capacitor. One end of the fifth switch and one end of the sixth switch are connected to the other electrode of the first flying capacitor and one electrode of the third flying capacitor. One end of the seventh switch and one end of the eighth switch are connected to the other electrode of the second flying capacitor and one electrode of the fourth flying capacitor. One end of the aforementioned ninth switch and one end of the aforementioned tenth switch are connected to the other electrode of the two electrodes of the aforementioned third flying capacitor. One end of the eleventh switch and one end of the twelfth switch are connected to the other electrode of the four flying capacitor. The other end of the first switch, the other end of the third switch, and one of the two electrodes of the first smoothing capacitor are connected to each other. The other ends of the second switch, the fourth switch, the fifth switch, and the seventh switch are connected to the other electrode of the first smoothing capacitor and one electrode of the second smoothing capacitor. The other ends of the sixth switch, the eighth switch, the ninth switch, and the eleventh switch are connected to the other electrode of the second smoothing capacitor and one electrode of the third smoothing capacitor. The other end of the tenth switch and the other end of the twelfth switch are connected to the other electrode of the third smoothing capacitor. One end of the aforementioned thirteenth switch and the other end are respectively connected to one electrode and the other electrode of the first smoothing capacitor, the second smoothing capacitor, or the third smoothing capacitor.

5. The tracker circuit according to claim 4, wherein, One end of the aforementioned thirteenth switch and the other end are respectively connected to one electrode and the other electrode of the aforementioned second smoothing capacitor. When the PAPR of the high-frequency signal amplified by the aforementioned power amplifier is less than the threshold, the aforementioned thirteenth switch remains open. When the PAPR is above the threshold, the fifth switch, the sixth switch, the seventh switch, and the eighth switch remain open, and the thirteenth switch remains closed.

6. The tracker circuit according to claim 4, wherein, The aforementioned switched capacitor circuit also includes a fourteenth switch and a fifteenth switch. One end of the aforementioned thirteenth switch and the other end are respectively connected to one electrode and the other electrode of the aforementioned second smoothing capacitor. One end of the fourteenth switch is connected to one electrode and the other electrode of the first flying capacitor, respectively. One end of the aforementioned fifteenth switch and the other end are respectively connected to one electrode and the other electrode of the aforementioned second flying capacitor.

7. The tracker circuit according to claim 6, wherein, When the PAPR of the high-frequency signal amplified by the aforementioned power amplifier is less than the threshold, the thirteenth, fourteenth, and fifteenth switches remain in the open state. When the PAPR is above the threshold, the fifth, sixth, seventh and eighth switches remain open, and the thirteenth, fourteenth and fifteenth switches remain closed.

8. The tracker circuit according to claim 4, wherein, The aforementioned switched capacitor circuit also includes a sixteenth switch. One end of the aforementioned thirteenth switch and the other end are respectively connected to one electrode and the other electrode of the aforementioned second smoothing capacitor. One end of the sixteenth switch and the other end are respectively connected to one electrode and the other electrode of the third smoothing capacitor.

9. The tracker circuit according to claim 8, wherein, The aforementioned switched capacitor circuit also includes a fourteenth switch and a fifteenth switch. One end of the fourteenth switch is connected to one electrode and the other electrode of the first flying capacitor, respectively. One end of the aforementioned fifteenth switch and the other end are respectively connected to one electrode and the other electrode of the aforementioned second flying capacitor.

10. The tracker circuit according to claim 8 or 9, wherein, The aforementioned switched capacitor circuit also includes a seventeenth switch and an eighteenth switch. One end of the aforementioned seventeenth switch and the other end are respectively connected to one electrode and the other electrode of the aforementioned third flying capacitor. One end of the eighteenth switch and the other end are respectively connected to one electrode and the other electrode of the fourth flying capacitor.

11. A tracker circuit, comprising: A switched capacitor circuit has a first mode and a second mode. In the first mode, a plurality of first discrete voltages are generated based on an input voltage. In the second mode, a plurality of second discrete voltages are generated based on the input voltage. The power modulation circuit is configured to selectively output at least one of the generated plurality of first discrete voltages or the plurality of second discrete voltages to a power amplifier. The number of the aforementioned multiple first discrete voltages is greater than the number of the aforementioned multiple second discrete voltages.

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