Multi-mode voltage tracker circuit

Abstract

A multimode voltage tracker circuit is provided. The multimode voltage tracker circuit is configured to generate a modulated voltage for amplifying a radio frequency (RF) signal, and the RF signal can be modulated in a wide modulation bandwidth range. In one non-limiting example, the multimode voltage tracker circuit can be configured to operate in a low modulation bandwidth (LMB) mode to generate an average power tracking (APT) modulated voltage for amplifying the RF signal when the RF signal is modulated in a lower modulation bandwidth (e.g., <50KHz). Thus, the multimode voltage tracker circuit can be suitable for supporting lower bandwidth communications in Internet of Things (IoT) networks with improved efficiency, stability, and performance.

Description

[0001] Related Applications

[0002] This application claims the benefit of Provisional Patent Application Serial No. 62 / 643,368, filed on Mar. 15, 2018, the disclosure of which is hereby incorporated herein by reference in its entirety. Technical Field

[0003] The technology of the present disclosure generally relates to envelope tracking (ET) circuits operating over a wide modulation bandwidth range. Background Art

[0004] To provide wireless communication services, mobile communication devices have become increasingly common in current society. The popularity of these mobile communication devices is partially driven by the multiple functions now available on these devices. The increased processing power in these devices means that mobile communication devices have evolved from simple communication tools into complex mobile multimedia centers that achieve an enhanced user experience.

[0005] Advanced wide-area wireless communication technologies defined by the Third Generation Partnership Project (3GPP), such as Long Term Evolution (LTE) and Fifth Generation New Radio (5G-NR), are widely regarded as the foundation of future wireless communication systems. Typically, in a wireless wide area network (WWAN), RF communication signals are modulated with a relatively wide bandwidth (e.g., greater than 180 KHz) and are conveyed continuously or periodically.

[0006] While supporting wide-area wireless communication technologies, mobile communication devices can form an Internet of Things (IoT) network with many unconventional communication devices (e.g., vehicles, household appliances, sensors, etc.) to enable a variety of human-machine interface applications. Compared with the RF signals conveyed in a WWAN, the RF signals conveyed in an IoT network are often modulated with a relatively narrow bandwidth (e.g., less than 15 KHz) and are conveyed sporadically.

[0007] Mobile communication devices often use power amplifiers to increase the output power of RF signals (e.g., to maintain sufficient energy per bit) before conveying them in a WWAN or an IoT network. In this regard, it may be necessary to design the power amplifier and associated voltage control circuits to effectively support RF signals modulated over a wide bandwidth range. Summary of the Invention

[0008] Embodiments of the present disclosure relate to a multi-mode voltage tracker circuit. The multi-mode voltage tracker circuit is configured to generate a modulated voltage for amplifying a radio frequency (RF) signal, and the RF signal can be modulated in a wide modulation bandwidth range. In one non-limiting example, the multi-mode voltage tracker circuit can be configured to operate in a low modulation bandwidth (LMB) mode to generate an average power tracking (APT) modulated voltage for amplifying the RF signal when the RF signal is modulated in a lower modulation bandwidth (e.g., <50KHz). Thus, the multi-mode voltage tracker circuit can be suitable for supporting lower bandwidth communications in Internet of Things (IoT) networks with improved efficiency, stability, and performance.

[0009] In one aspect, a multi-mode voltage tracker circuit is provided. The multi-mode voltage tracker circuit includes an input node configured to receive a modulated target voltage. The multi-mode voltage tracker circuit further includes an output node configured to output a modulated voltage. The multi-mode voltage tracker circuit further includes an ET tracker circuit coupled between the input node and the output node. The ET tracker circuit is configured to generate the modulated voltage at the output node based on the modulated target voltage. The multi-mode voltage tracker circuit further includes a control circuit. The control circuit is configured to determine whether the ET tracker circuit is configured to operate in the LMB mode. The control circuit is further configured to control the ET tracker circuit to generate an APT modulated voltage at the output node based on the modulated target voltage in response to the ET tracker circuit being configured to operate in the LMB mode.

[0010] In another aspect, a multimode voltage tracker circuit is provided. The multimode voltage tracker circuit includes an input node configured to receive a modulated target voltage. The multimode voltage tracker circuit further includes an output node configured to output a modulated voltage. The multimode voltage tracker circuit further includes an ET tracker circuit coupled between the input node and the output node. The ET tracker circuit is configured to generate the modulated voltage at the output node based on the modulated target voltage. The multimode voltage tracker circuit further includes a control circuit. The control circuit is configured to determine, based on a predefined threshold, whether the ET tracker circuit is configured to operate in a low modulation bandwidth (LMB) mode or a high modulation bandwidth (HMB) mode. The control circuit is further configured to control the ET tracker circuit to generate an APT modulated voltage at the output node based on the modulated target voltage in response to the ET tracker circuit being configured to operate in the LMB mode. The control circuit is further configured to control the ET tracker circuit to generate an ET modulated voltage at the output node based on the modulated target voltage in response to the ET tracker circuit being configured to operate in the HMB mode.

[0011] Those skilled in the art will appreciate the scope of the present disclosure and additional aspects thereof after reading the following detailed description of the preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0013] Figure 1A is a schematic diagram of an exemplary existing voltage tracker circuit that may not be able to hold an envelope tracking (ET) modulated voltage at a required level for amplifying an RF signal modulated in a lower modulation bandwidth;

[0014] Figure 1B is a graphical diagram providing an exemplary illustration of an ET modulation voltage that decreases over time due to Figure 1A capacitor discharge in an existing ET voltage tracker circuit;

[0015] Figure 2 is a schematic diagram of an exemplary multimode voltage tracker circuit configured according to an embodiment of the present disclosure to support a low modulation bandwidth (LMB) operating mode and a high modulation bandwidth (HMB) operating mode; and

[0016] Figure 3is a schematic diagram of an exemplary multi-mode voltage tracker circuit configured according to another embodiment of the present disclosure to support the LMB very high power (VHP) operating mode. Detailed Description

[0017] The embodiments set forth below represent the necessary information enabling those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. After reading the following description with reference to the accompanying drawings, those skilled in the art will understand the concepts of the present disclosure and will recognize applications of these concepts not particularly set forth herein. It should be understood that these concepts and applications are within the scope of the present disclosure and the appended claims.

[0018] It will be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0019] It will be understood that when an element such as a layer, region, or substrate is referred to as being "on" or extending "onto" another element, the element can be directly on or directly extend onto the other element, or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly extending onto" another element, no intervening elements are present. Similarly, it will be understood that when an element such as a layer, region, or substrate is referred to as being "above" or extending "above" another element, the element can be directly above or directly extend above the other element, or intervening elements may also be present. In contrast, when an element is referred to as being "directly above" or "directly extending above" another element, no intervening elements are present. It will also be understood that when an element is referred to as being "connected" or "coupled" to another element, the element can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, no intervening elements are present.

[0020] Relative terms such as "beneath", "above", "upper", "lower", "horizontal", or "vertical" may be used herein to describe the relationship of one element, layer, or region to another element, layer, or region as illustrated in the figures. It will be understood that these terms and the terms discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the figures.

[0021] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the disclosure. As used herein, the singular forms "a" and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It will also be understood that the term "comprises" when used herein specifies the presence of certain features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0022] Unless otherwise specified, the meanings of all terms (including technical and scientific terms) used herein are the same as those commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will also be understood that the terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art, and not in an idealized or overly formal sense, unless expressly so specified herein.

[0023] Embodiments of the present disclosure relate to a multimode voltage tracker circuit. The multimode voltage tracker circuit is configured to generate a modulated voltage for amplifying a radio frequency (RF) signal, and the RF signal can be modulated in a wide modulation bandwidth range. In a non-limiting example, the multimode voltage tracker circuit can be configured to operate in a low modulation bandwidth (LMB) mode to generate an average power tracking (APT) modulated voltage for amplifying the RF signal when the RF signal is modulated in a lower modulation bandwidth (e.g., <50KHz). Thus, the multimode voltage tracker circuit can be suitable for supporting lower bandwidth communications in Internet of Things (IoT) networks with improved efficiency, stability, and performance.

[0024] Before discussing the multimode voltage tracker circuit of the present disclosure, first refer to Figure 1A and Figure 1B to discuss a brief overview of existing voltage tracker circuits to help understand the challenges associated with generating a modulated voltage for amplifying IoT communication signals with a lower modulation bandwidth. The discussion of specific exemplary aspects of the multimode voltage tracker circuit according to the present disclosure refers to Figure 2 which begins below.

[0025] In this regard, Figure 1A is a schematic diagram of an exemplary existing voltage tracker circuit 10 that may not be able to hold the ET modulated voltage V CC at the required level for amplifying the RF signal 12 modulated in a lower modulation bandwidth. The existing voltage tracker circuit 10 includes an ET tracker circuit 14. The ET tracker circuit 14 includes an amplifier circuit 16 and a charge pump circuit 18.

[0026] The amplifier circuit 16 is configured to generate an ET output voltage V' at the amplifier output 20 based on the modulated target voltage V 目标 In a non-limiting example, the modulated target voltage V can be provided in the form of a differential voltage. The amplifier output 20 is coupled to the output node 22 of the existing voltage tracker circuit 10 via an offset capacitor 24. The offset capacitor 24 is configured to raise (e.g., by approximately 1V) the ET output voltage V' to generate an ET modulated voltage V at the output node 22 CC 目标 CC CC

[0027] The charge pump circuit 18 includes a charge pump 26, which can be, for example, a direct current (DC) to DC (DC - DC) buck - boost circuit. The charge pump 26 is configured to generate a DC voltage V based on the battery voltage V BAT DC An ET controller (ETC) 28 is provided to control the charge pump 26 to generate various levels of the DC voltage V, and the ETC can be a bang - bang controller. In a non - limiting example, the ETC 28 is capable of controlling the charge pump 26 to generate a DC voltage V of 0V, V DC BAT or 2×V BAT DC The charge pump circuit 18 includes an inductor 30, which is configured to induce a current I at the output node 22 based on the DC voltage V DC CC The charge pump circuit 18 further includes a flying capacitor 32, which is coupled between the inductor 30 and the ground 34

[0028] The output node 22 is coupled to the amplifier circuit 36. The amplifier circuit 36 is configured to amplify an RF signal from an input power P to an output power P based on the ET modulated voltage V CC IN OUT In one non - limiting example, the RF signal 12 can be a Long - Term Evolution (LTE) or 5G - New Radio (5G - NR) RF signal corresponding to a relatively high modulation bandwidth (e.g., ≥180KHz). In another non - limiting example, the RF signal 12 can be an IoT RF signal corresponding to a relatively low modulation bandwidth (e.g., ≤15KHz).

[0029] Notably, the RF signal 12 can be modulated to follow a time - varying power envelope that can generate relatively high peak power from time to time. Accordingly, the ET tracker circuit 14 is required to provide an ET modulated voltage V and a current I with sufficient levels CC ​​​​​​​​​​​CC such that the amplifier circuit 36 can amplify the RF signal 12 to an output power P corresponding to a higher peak power of the time-varying power envelope OUT . For example, the RF signal 12 can have a peak power exceeding 28.5 dBm, and the amplifier circuit 36 is required to amplify the RF signal 12 to a class 2 output power exceeding 26 dBm. If the amplifier circuit 36 has a 45% power amplifier efficiency (PAE) and the ET-modulated voltage V CC is at 5 V, the current I CC generated by the ET tracker circuit 14 would be required to be approximately 314.6 mA.

[0030] Initially, the charge pump circuit 18 is configured to provide the current I CC by discharging the flying capacitor 32. As the flying capacitor 32 discharges, the current I CC decreases accordingly, creating a deficit in the current I CC . Consequently, the amplifier circuit 16 is forced to act as a source of a portion of the current I CC to make up the deficit. As a result, the offset capacitor 24 begins to discharge, causing the ET-modulated voltage V CC to drop below 5 V.

[0031] Figure 1B is a graphical plot 38 providing an exemplary illustration of the ET-modulated voltage V CC , where the ET-modulated voltage V CC decreases over time due to Figure 1A the discharge of capacitors in the existing voltage tracker circuit 10. Reference will be made to the elements of Figure 1B in conjunction with Figure 1A , and the elements will not be described further herein.

[0032] The graphical plot 38 includes an ideal voltage curve 40 and an actual voltage curve 42. As shown by the ideal voltage curve 40, the existing voltage tracker circuit 10 is required to hold the ET-modulated voltage V CC at approximately 5 V between times T1 and T2. However, as shown by the actual voltage curve 42, due to the discharge of the flying capacitor 32 and the offset capacitor 24, the ET-modulated voltage V CC begins to decrease at time T3 (T1 < T3 < T2). In other words, the existing voltage tracker circuit 10 can only hold the ET-modulated voltage V CC at 5 V between times T1 and T3. In a non-limiting example, the duration between times T1 and T3 can be approximately 15 microseconds (μs).

[0033] When modulating the RF signal 12 with a relatively high modulation bandwidth (e.g., ≥50 KHz), the existing voltage tracker circuit 10 only needs to hold the ET modulation voltage V CC at 5V for approximately 5 μs. At this point, assuming that the existing voltage tracker circuit 10 can hold the ET modulated voltage V CC at 5V for a longer duration, the voltage drop as shown in the actual voltage curve 42 may not have an adverse effect on the amplifier circuit 36.

[0034] However, when the RF signal 12 is an IoT RF signal, the RF signal 12 is typically modulated with a relatively low modulation bandwidth between 3.75 KHz and 15 KHz. At this point, the existing voltage tracker circuit 10 may need to hold the ET modulated voltage V CC at 5V for up to 280 μs, which far exceeds the capabilities of the existing voltage tracker circuit 10. As a result, the amplifier circuit 36 can be negatively affected by the drop in the ET modulated voltage V CC . Therefore, it may be necessary to enhance the existing voltage tracker circuit 10 to amplify the RF signal 12 over a wide range of modulation bandwidths.

[0035] At this point, Figure 2 is a schematic diagram of an exemplary multimode voltage tracker circuit 44, which is configured according to an embodiment of the present disclosure to support a low modulation bandwidth (LMB) operating mode and a high modulation bandwidth (HMB) operating mode. The multimode voltage tracker circuit 44 includes an output node 46, which is configured to output a modulated voltage V CC . The output node 46 can be coupled to at least one amplifier circuit 48. The amplifier circuit 48 is configured to amplify the RF signal 50 based on the modulated voltage V CC , and the amplifier circuit can be a single-stage, two-stage, or differential amplifier circuit.

[0036] When modulating the RF signal 50 with a modulation bandwidth below a predefined threshold (e.g., <50 KHz), the multimode voltage tracker circuit 44 can be configured to operate in the LMB mode. In a non-limiting example, when the RF signal 50 is communicated in an IoT network using IoT-enabled devices such as smart devices and smart sensors, the multimode voltage tracker circuit 44 operates in the LMB mode.

[0037] In contrast, when modulating the RF signal 50 with a modulation bandwidth greater than or equal to the predefined threshold (e.g., ≥50 KHz), the multimode voltage tracker circuit is configured to operate in the HMB mode. In a non-limiting example, when the RF signal 50 is communicated in a WWAN such as an LTE network and a 5G-NR network, the multimode voltage tracker circuit 44 operates in the HMB mode.

[0038] As discussed in detail below, the multimode voltage tracker circuit 44 can be configured to output an APT-modulated voltage as the modulated voltage V in the LMB mode CC or output an ET-modulated voltage as the modulated voltage V in the HMB mode CC . By generating an APT-modulated voltage at the output node 46 in the LMB mode, the multimode voltage tracker circuit 44 has the potential to maintain the modulated voltage V CC for a duration required for the amplifier circuit 48 to amplify the RF signal 50 (e.g., Figure 1B the duration T1 to T2), thereby helping to improve the efficiency, stability, and performance of communication in the IoT network. Additionally, by generating an ET-modulated voltage at the output node 46 in the HMB mode, it is possible to improve the linearity and efficiency of the amplifier circuit 48 for communication in LTE and / or 5G-NR networks.

[0039] The multimode voltage tracker circuit 44 includes an input node 52 configured to receive a modulated target voltage V 目标 , the modulated target voltage V 目标 defining a time-varying target voltage envelope. In a non-limiting example, the input node 52 is coupled to a transceiver circuit (not shown) configured to generate the modulated target voltage V 目标 and the RF signal 50. In another non-limiting example, the modulated target voltage V 目标 can be provided as a differential voltage.

[0040] The multimode voltage tracker circuit 44 includes an ET tracker circuit 54 coupled between the input node 52 and the output node 46. The ET tracker circuit 54 is configured to generate the modulated voltage V 目标 based on the modulated target voltage V CC . The ET tracker circuit 54 can be configured to generate the modulated voltage V 目标 as an APT-modulated voltage or an ET-modulated voltage based on the modulated target voltage V CC . When the ET tracker circuit 54 generates the modulated voltage V CC as an ET-modulated voltage, the modulated voltage V CC corresponds to a time-varying voltage envelope that tracks the time-varying target envelope associated with the modulated target voltage V 目标 . The ET tracker circuit 54 can be preconfigured to operate in the LMB mode or the HMB mode. In a non-limiting example, the preconfiguration information can be stored in a register in the ET tracker circuit 54.

[0041] The multi-mode voltage tracker circuit 44 includes a control circuit 56, which can be, for example, a microprocessor, a microcontroller, or a field programmable gate array (FPGA). The control circuit 56 can include an internal memory (e.g., a register) for storing predetermined parameters such as predefined thresholds for determining the LMB mode or the HMB mode.

[0042] In one non-limiting example, the control circuit 56 receives an indication signal 57 from a transceiver coupled to the input node 52. The indication signal 57 can indicate the modulation bandwidth of the RF signal 50. Accordingly, the control circuit 56 is capable of comparing the modulation bandwidth indicated by the indication signal 57 with a predefined threshold to determine whether the ET tracker circuit 54 operates in the LMB mode or the HMB mode.

[0043] In another non-limiting example, the ET tracker circuit 54 can be preconfigured to operate in the LMB mode or the HMB mode. In this regard, the control circuit 56 can be programmed (e.g., via an external device) to store the preconfigured operating mode of the ET tracker circuit 54 in an internal memory (e.g., a register). Thus, the control circuit 56 can determine whether the ET tracker circuit 54 operates in the LMB mode or the HMB mode based on the stored operating mode of the ET tracker circuit 54.

[0044] In response to determining that the ET tracker circuit 54 is configured to operate in the LMB mode, the control circuit 56 controls the ET tracker circuit 54 to generate an APT-modulated voltage at the output node 46 based on the modulated target voltage V 目标 In contrast, in response to determining that the ET tracker circuit 54 is configured to operate in the HMB mode, the control circuit 56 controls the ET tracker circuit 54 to generate an ET-modulated voltage at the output node 46 based on the modulated target voltage V 目标 at the output node 46.

[0045] The ET tracker circuit 54 includes an amplifier circuit 58 and a charge pump circuit 60. The amplifier circuit 58 is configured to generate an output voltage V' at the amplifier output 62 based on the modulated target voltage V 目标 at the amplifier output 62. The amplifier output 62 is coupled to the output node 46 via an offset capacitor 64. The offset capacitor 64 is configured to raise the output voltage V' CC (e.g., by approximately 1V) to generate a modulated voltage V CC at the output node 46. CC

[0046] The charge pump circuit 60 includes a charge pump 66, which can be, for example, a DC-DC buck-boost circuit. The charge pump 66 is configured to generate a voltage based on the battery voltage V BATGenerate a DC voltage V DC An ET controller (ETC) 68 is provided to control the charge pump 66 to generate DC voltages V of various levels DC , and the ETC can be a bang-bang controller. In a non-limiting example, the ETC 68 is capable of controlling the charge pump 66 to generate DC voltages V of 0V, V BAT or 2×V BAT . DC The charge pump circuit 60 includes an inductor 70 configured to induce a current I at the output node 46 based on the DC voltage V DC . CC The charge pump circuit 60 further includes a flying capacitor 72 connected between the inductor 70 and ground 74. The ET tracker circuit 54 can also include an average power tracking controller (APTC) 76. Similar to the ETC 68, the APTC 76 is also connected to the charge pump 66.

[0047] In a first non-limiting example, the control circuit 56 activates the APTC 76 and the charge pump circuit 60 in the LMB mode. Accordingly, the APTC 76 controls the charge pump circuit 60 to generate an APT-modulated voltage based on the modulated target voltage V 目标 , which can be equal to 0V, V BAT or 2×V BAT . CC In addition, the charge pump circuit 60 also generates a current I at the output node 46.

[0048] The control circuit activates the ETC 68, the charge pump circuit 60 and the amplifier circuit 58 in the HMB mode in a second non-limiting example. Accordingly, the amplifier circuit 58 generates an ET-modulated voltage based on the modulated target voltage V 目标 , and the charge pump circuit 60 generates a current I at the output node 46 based on the battery voltage V BAT . CC The control circuit 56 can deactivate the APTC 76 in the HMB mode.

[0049] The ET tracker circuit 54 can include an output switching circuit 78, which can be implemented based on any type, number and configuration of suitable switches. The output switching circuit 78 can be configured to connect the charge pump circuit 60 and the amplifier circuit 58 to the output node 46. The amplifier circuit 58 can be connected to the output switching circuit 78 via an offset capacitor 64.

[0050] In the LMB mode, the control circuit 56 can control the output switching circuit 78 to connect the charge pump circuit 60 to the output node 46 to provide the APT - modulated voltage to the output node 46. Accordingly, the control circuit 56 can control the output switching circuit 78 to decouple the amplifier circuit 58 from the output node 46. In contrast, in the HMB mode, the control circuit 56 can control the output switching circuit 78 to connect the charge pump circuit 60 and the amplifier circuit 58 to the output node 46 to provide the ET - modulated voltage to the output node 46.

[0051] The multimode voltage tracker circuit 44 can include an input switching circuit 80. Similar to the output switching circuit 78, the input switching circuit 80 can be implemented based on any type, number, and configuration of suitable switches. The input switching circuit 80 is capable of being connected to the input node 52 to receive the modulated target voltage V 目标 .

[0052] In this regard, in the LMB mode, the control circuit 56 can control the input switching circuit 80 to provide the modulated target voltage V 目标 to the APTC 76 while decoupling the ETC 68 from the input switching circuit 80. In a non - limiting example, the APTC 76 can be directly or via an APT voltage adapter 82 connected to the input switching circuit 80.

[0053] In contrast, in the HMB mode, the control circuit 56 can control the input switching circuit 80 to provide the modulated target voltage V 目标 to the ETC 68 and the amplifier circuit 58 while decoupling the APTC 76 from the input switching circuit 80. In a non - limiting example, the ETC 68 and the amplifier circuit 58 can be directly or via an ET voltage adapter 84 connected to the input switching circuit 80.

[0054] The ET tracker circuit 54 can be configured to include additional amplifier circuits and additional charge pump circuits for supporting the LMB very - high - power (VHP) operating mode. In this regard, Figure 3 is a schematic diagram of an exemplary multimode voltage tracker circuit 44A, which is configured according to another embodiment of the present disclosure to support the LMB VHP operating mode. Figure 2 Common elements between Figure 3 are shown with common element symbols herein and thus will not be described again herein.

[0055] The multimode voltage tracker circuit 44A includes a second output node 46A, which is configured to output a second modulated voltage V CCAOutput to at least one second amplifier circuit 48A. The multi-mode voltage tracker circuit 44A includes an ET tracker circuit 54A. The ET tracker circuit 54A further includes a second charge pump circuit 60A and a second amplifier circuit 58A that are functionally equivalent to the charge pump circuit 60 and the amplifier circuit 58, respectively. Similar to the charge pump circuit 60, the second charge pump circuit 60A can be configured to generate a second APT-modulated voltage and a second current. Moreover, similar to the amplifier circuit 58, the second amplifier circuit 58A can be configured to generate a second ET-modulated voltage. The ET tracker circuit 54A further includes a second ETC 68A coupled to the second charge pump circuit 60A. The second ETC 68A can be coupled to the input switching circuit 80 via a second ET voltage adapter 84A. The second charge pump circuit 60A includes a second charge pump 66A, a second inductor 70A, and a second flying capacitor 72A that are functionally equivalent to the charge pump 66, the inductor 70, and the flying capacitor 72, respectively. The APTC 76 can be configured to control both the charge pump circuit 60 and the second charge pump circuit 60A.

[0056] The control circuit 56 can determine that the ET tracker circuit 54A is configured to operate in the LMBVHP mode based on a predefined power threshold, which can be pre-stored in an internal memory. For example, the control circuit 56 can receive a power indication of the RF signal 50 via an indication signal 57 and compare the received power indication with the predefined power threshold to determine whether the ET tracker circuit 54A is configured to operate in the LMB VHP mode.

[0057] Accordingly, the control circuit 56 can activate both the charge pump circuit 60 and the second charge pump circuit 60A to provide the APT-modulated voltage and the second APT-modulated voltage to the output node 46, respectively. In this regard, the control circuit 56 can control the input switching circuit 80 to provide the modulated target voltage V 目标 to the APTC 76, and control the output switching circuit 78 to couple both the charge pump circuit 60 and the second charge pump circuit 60A to the output node 46. The control circuit 56 can deactivate both the amplifier circuit 58 and the second amplifier circuit 58A in the LMB VHP mode.

[0058] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered to be within the scope of the concepts disclosed herein and the subsequent claims.

Claims

1. A multimode voltage tracker circuit, the multimode voltage tracker circuit comprising: An input node configured to receive a modulated target voltage; An output node configured to output a modulated voltage for amplifying a radio frequency (RF) signal; An envelope tracking (ET) tracker circuit coupled between the input node and the output node, the ET tracker circuit comprising: A charge pump circuit configured to generate an average power tracking (APT) modulated voltage and current; and An amplifier circuit configured to generate an ET modulated voltage; and A control circuit configured to: Determine that the ET tracker circuit is configured to operate in a low modulation bandwidth (LMB) mode, in which the RF signal is modulated at a modulation bandwidth below a predefined threshold; In response to the ET tracker circuit being configured to operate in the LMB mode, deactivate the amplifier circuit and activate the charge pump circuit to generate the APT modulated voltage as the modulated voltage at the output node based on the modulated target voltage and maintain the APT modulated voltage at a desired level for a first duration; Determine that the ET tracker circuit is configured to operate in a high modulation bandwidth (HMB) mode, in which the RF signal is modulated at a modulation bandwidth greater than or equal to the predefined threshold; and In response to the ET tracker circuit being configured to operate in the HMB mode, activate the amplifier circuit to generate the ET modulated voltage as the modulated voltage at the output node based on the modulated target voltage and maintain the ET modulated voltage at the desired level for a second duration shorter than the first duration.

2. The multimode voltage tracker circuit of claim 1, wherein the control circuit is further configured to determine whether the ET tracker circuit is configured to operate in the LMB mode or the HMB mode based on pre-stored configuration information. The multimode voltage tracker circuit of claim 1, wherein the predefined threshold is 50 KHz.

4. The multimode voltage tracker circuit of claim 1, wherein the ET tracker circuit further comprises: An ET controller and an APT controller, each coupled to the charge pump circuit.

5. The multimode voltage tracker circuit of claim 4, wherein the control circuit is further configured to activate the APT controller and deactivate the ET controller in the LMB mode.

6. The multimode voltage tracker circuit of claim 5, wherein the control circuit is further configured to deactivate the ET controller in the LMB mode.

7. The multimode voltage tracker circuit of claim 4, wherein the control circuit is further configured to activate the ET controller and deactivate the APT controller in the HMB mode.

8. The multimode voltage tracker circuit of claim 4, wherein: The ET tracker circuit further includes an output switching circuit configured to couple the charge pump circuit and the amplifier circuit to the output node; and The control circuit is further configured to: In the LMB mode, control the output switching circuit to couple the charge pump circuit to the output node to provide the APT modulated voltage and the current to the output node; And In the HMB mode, control the output switching circuit to couple the amplifier circuit to the output node to provide the ET modulated voltage and the current to the output node.

9. The multimode voltage tracker circuit of claim 8, wherein the amplifier circuit is coupled to the output switching circuit via an offset capacitor.

10. The multimode voltage tracker circuit of claim 4, the multimode voltage tracker circuit further includes an input switching circuit coupled to a transceiver circuit and configured to receive the modulated target voltage from the transceiver circuit.

11. The multimode voltage tracker circuit of claim 10, wherein the control circuit is further configured to control the input switching circuit to provide the modulated target voltage to the APT controller in the LMB mode.

12. The multimode voltage tracker circuit of claim 11, the multimode voltage tracker circuit further includes an APT voltage adapter coupled between the input switching circuit and the APT controller.

13. The multimode voltage tracker circuit of claim 10, wherein the control circuit is further configured to control the input switching circuit to provide the modulated target voltage to the ET controller and the amplifier circuit in the HMB mode.

14. The multimode voltage tracker circuit of claim 13, the multimode voltage tracker circuit further includes an ET voltage adapter coupled between the input switching circuit, the ET controller and the amplifier circuit.

15. The multimode voltage tracker circuit of claim 4, the multimode voltage tracker circuit further includes: A second charge pump circuit configured to generate a second APT modulated voltage and a second current; A second amplifier circuit configured to generate a second ET modulated voltage; And A second ET controller coupled to the second charge pump circuit.

16. The multimode voltage tracker circuit of claim 15, wherein the control circuit is further configured to: Determine whether the ET tracker circuit is configured to operate in a LMB very high power VHP mode based on a predefined power threshold; and In response to determining that the ET tracker circuit is configured to operate in the LMB very high power VHP mode, activate the charge pump circuit and the second charge pump circuit to provide the APT modulated voltage and the second APT modulated voltage to the output node.

17. The multimode voltage tracker circuit as claimed in claim 16, wherein the control circuit is further configured to deactivate the ET controller, the second ET controller, the amplifier circuit, and the second amplifier circuit in the LMB very high power VHP mode.

18. A multimode voltage tracker circuit, the multimode voltage tracker circuit comprising: an input node configured to receive a modulated target voltage; an output node configured to output a modulated voltage for amplifying a radio frequency RF signal; an envelope tracking ET tracker circuit coupled between the input node and the output node, the ET tracker circuit comprising: a charge pump circuit configured to generate an average power tracking APT modulated voltage and current; and an amplifier circuit configured to generate an ET modulated voltage; and a control circuit configured to: determine that the ET tracker circuit is configured to operate in a low modulation bandwidth LMB mode, in which the RF signal is modulated at a modulation bandwidth below a predefined threshold; in response to the ET tracker circuit being configured to operate in the LMB mode, deactivate the amplifier circuit and activate the charge pump circuit to generate the APT modulated voltage as the modulated voltage at the output node based on the modulated target voltage and maintain the APT modulated voltage at a desired level for a first duration; determine that the ET tracker circuit is configured to operate in a high modulation bandwidth HMB mode, in which the RF signal is modulated at a modulation bandwidth greater than or equal to the predefined threshold; and in response to the ET tracker circuit being configured to operate in the HMB mode, activate the amplifier circuit to generate the ET modulated voltage as the modulated voltage at the output node based on the modulated target voltage and maintain the ET modulated voltage at the desired level for a second duration shorter than the first duration.

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