Envelope curve tracking system, portable device, and method of envelope curve tracking

Abstract

To provide an envelope curve tracking system, a portable device, and a method, for managing a power of a RF signal transmission.SOLUTION: An envelope curve tracking system 100 comprising separately a DC path and an AC path, and generates a power amplifier supply voltage VPA for a power amplifier PA. The system includes: a multilevel supply (MLS)DC / DC converter 72 that outputs a plurality of adjusted voltages VMLSa, VMLSb, VMLSc,...VMLSn; a MLS converter 81 that controls, with time, selection of each adjusted voltage on the basis of an envelope curve signal ENVELOPE corresponding to an envelope curve of a RF signal RFOUT amplified by the power amplifier; an AC route filter 91 that is coupled to between an output of the MLS converter and the power amplifier supply voltage; and a DC path filter 73 that is coupled to between a DC voltage VDC and the power amplifier supply voltage.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] Embodiments of the present invention relate to electronic systems, and more particularly to radio frequency (RF) electronic devices. This invention relates to a power amplifier. [Background technology]

[0002] In RF communications systems, a device is used to amplify an RF signal for transmission via an antenna. Power amplifiers are used to extend battery life and / or provide adequate transmit power levels. It is important to manage the power of RF signal transmission to achieve this.

[0003] Examples of RF communication systems that have one or more power amplifiers include mobile phones, tablets, base stations, and the like. Stations, network access points, customer premises equipment (CPE), laptops, and web This includes, but is not limited to, wireless electronic devices. For example, cellular standards, wireless local area networks, Wireless LAN (WLAN) standard, and / or any other suitable communication standard. In wireless devices that transmit signals, power amplifiers are often used to amplify the RF signals. RF signals can be used, for example, for 5th generation (5G) communications in Frequency Range 1 (FR1). For example, the range of about 410MHz to about 7.125GHz, about 30kHz to 300GHz It may have frequencies in the range z. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2012 / 0269240 [Patent Document 2] US Patent Application Publication No. 2013 / 0207731 Summary of the Invention

[0005] In certain embodiments, the present disclosure provides a power amplifier for amplifying a radio frequency signal. a power amplifier configured to receive power from a supply voltage; an envelope signal generator configured to generate the power amplifier supply voltage based on a corresponding envelope signal; and a tracker for outputting a plurality of regulated voltages. a DC / DC converter configured to output the plurality of regulated voltages and the envelope signal; a modulator configured to generate a modulator output voltage based on a a first filter coupled between the DC voltage and the power amplifier supply voltage; and a second filter coupled between the pressure.

[0006] In various embodiments, a DC / DC converter is further configured to generate the DC voltage. According to a number of embodiments, the DC / DC converter is configured to convert the plurality of regulated voltages into Configured to generate DC voltages with different pulse width modulation sequences for either will be done.

[0007] In some embodiments, a DC / DC converter is provided to receive the battery voltage and A plurality of regulated voltages and a DC voltage are generated based on providing a DC / DC conversion of the battery voltage. It is constructed to generate.

[0008] In some embodiments, the plurality of regulated voltages each have a different voltage level. It has a

[0009] In various embodiments, the envelope tracker further comprises a plurality of regulated voltages connected to ground. The input / output terminals include a plurality of decoupling capacitors coupled between corresponding ones of the input / output terminals.

[0010] In some embodiments, the modulators each have a modulator output voltage and the plurality of adjustments. The power supply includes a plurality of switches coupled between the corresponding regulated voltages of the power supply and the corresponding regulated voltages.

[0011] In some embodiments, the first filter comprises at least one series inductor and At least one shunt capacitor. According to certain embodiments, the first filter Further, a DC blocking capacitor is connected in series between the modulator output voltage and the power amplifier supply voltage. Including Sita.

[0012] In various embodiments, the second filter includes at least one series inductor and at least one The input / output terminals include at least one shunt capacitor.

[0013] In some embodiments, the envelope tracker further comprises an AC path through the first filter; A controllable delay circuit configured to control the relative delay between the DC path through the second filter. According to a number of embodiments, the controllable delay circuits each include a delay circuit for each of the plurality of A plurality of controllable delay buffers configured to control the delay of each of the regulated voltages. Includes Fa.

[0014] In various embodiments, a DC path through a second filter is provided to connect the envelope tracker to the power amplifier. It transfers at least 75 percent of the energy imparted to it.

[0015] In certain embodiments, the present disclosure relates to an envelope tracker. a power amplifier supply voltage terminal configured to output a power amplifier supply voltage; a DC / DC converter configured to output a plurality of regulated voltages based on a a converter configured to generate a modulator output voltage based on the number of regulated voltages and the envelope signal; a modulator and an AC path filter coupled between the modulator output voltage and the power amplifier supply voltage. and a DC path filter coupled between a DC voltage and the power amplifier supply voltage. nothing.

[0016] In some embodiments, the DC / DC converter further comprises a According to a number of embodiments, the DC / DC converter is configured to To generate a DC voltage with a different pulse width modulation sequence for each voltage, It is composed.

[0017] In some embodiments, a DC / DC converter is provided to receive the battery voltage and A plurality of regulated voltages and a DC voltage are generated based on providing a DC / DC conversion of the battery voltage. It is constructed to generate.

[0018] In various embodiments, the multiple regulated voltages each have a different voltage level. do.

[0019] In some embodiments, the envelope tracker further comprises a plurality of regulated voltages connected to ground. and a plurality of decoupling capacitors coupled between the corresponding regulated voltages of the first and second inputs.

[0020] In some embodiments, the modulators each have a modulator output voltage and the plurality of adjustments. The power supply includes a plurality of switches coupled between the corresponding regulated voltages of the power supply and the corresponding regulated voltages.

[0021] In various embodiments, the AC path filter comprises at least one series inductor and At least one shunt capacitor. According to certain embodiments, the AC path filter The filter further comprises a DC block capacitor connected in series between the modulator output voltage and the power amplifier supply voltage. Includes Capashta.

[0022] In some embodiments, the DC path filter includes at least one series inductor , and at least one shunt capacitor.

[0023] In various embodiments, the envelope tracker further comprises an AC path through a first filter and a second filter. A controllable delay circuit configured to control the relative delay between the DC path through the filter. According to a number of embodiments, the controllable delay circuits each include one of the plurality of adjustable delay circuits. a plurality of controllable delay buffers configured to control a delay of each regulated voltage of the regulated voltages. Includes.

[0024] In some embodiments, the DC path filter is connected to the envelope tracker via the power amplifier supply. Carries at least 75 percent of the energy applied to the voltage terminals.

[0025] In certain embodiments, the present disclosure relates to a mobile device. a transceiver configured to generate a radio frequency transmit signal; and US20130233633A1 - Front end circuit including a power amplifier configured to receive power from a power amplifier supply voltage - Google Patents and determining a power amplifier supply voltage based on an envelope signal corresponding to an envelope of the radio frequency transmission signal. and a power management circuit including an envelope tracker configured to generate a voltage. a DC / DC converter configured to output a plurality of regulated voltages; a modulator configured to generate a modulator output voltage based on the envelope signal and the modulator voltage; a first filter coupled between the modulator output voltage and the power amplifier supply voltage; and a second filter coupled between the C voltage and the power amplifier supply voltage.

[0026] In some embodiments, the DC / DC converter further comprises a According to a number of embodiments, the DC / DC converter is configured to To generate a DC voltage with a different pulse width modulation sequence for each voltage, It is composed.

[0027] In some embodiments, the portable device further comprises a battery that provides a battery voltage; The DC / DC converter provides a DC / DC conversion of the battery voltage based on a number of adjustments. The converter is configured to generate a converted voltage and a DC voltage.

[0028] In some embodiments, the plurality of regulated voltages each have a different voltage level. It has a

[0029] In various embodiments, the envelope tracker further comprises a plurality of regulated voltages connected to ground. The input / output terminals include a plurality of decoupling capacitors coupled between corresponding ones of the input / output terminals.

[0030] In some embodiments, the modulators each have a modulator output voltage and the plurality of adjustments. The power supply includes a plurality of switches coupled between the corresponding regulated voltages of the power supply and the corresponding regulated voltages.

[0031] In some embodiments, the first filter comprises at least one series inductor and At least one shunt capacitor. According to certain embodiments, the first filter Further, a DC blocking capacitor is connected in series between the modulator output voltage and the power amplifier supply voltage. Including Sita.

[0032] In some embodiments, the second filter includes at least one series inductor, and and at least one shunt capacitor.

[0033] In various embodiments, the envelope tracker further comprises an AC path through a first filter and a second filter. A controllable delay circuit configured to control the relative delay between the DC path through the filter. According to a number of embodiments, the controllable delay circuits each include one of the plurality of adjustable delay circuits. a plurality of controllable delay buffers configured to control a delay of each regulated voltage of the regulated voltages. Includes.

[0034] In some embodiments, a DC path through the second filter transfers power from the envelope tracker to the Carry at least 75 percent of the energy provided to the amplifier.

[0035] In certain embodiments, the present disclosure relates to a method of envelope tracking, the method comprising: and amplifying the radio frequency signal using a power amplifier supply voltage. and outputting a plurality of regulated voltages from the DC / DC converter. using a modulator to generate a modulator output voltage based on the plurality of regulated voltages and the envelope signal. and generating an envelope signal corresponding to an envelope of the radio frequency signal. The present invention further uses a first filter that exists between the modulator output voltage and the power amplifier supply voltage. and controlling the power amplifier supply voltage by a DC voltage and and controlling the power amplifier supply voltage using a second filter present in the

[0036] In some embodiments, the method further comprises converting the DC voltage using a DC / DC converter. According to a number of embodiments, the method further includes generating a plurality of regulated voltages. This involves generating DC voltages with different pulse width modulation sequences for each. nothing.

[0037] In various embodiments, the method further comprises providing a DC / DC conversion of the battery voltage. The method includes generating a plurality of regulated voltages and a DC voltage based on the regulated voltage.

[0038] In some embodiments, the plurality of regulated voltages each have a different voltage level. It has a

[0039] In some embodiments, the method further comprises: This involves using Sita to give a DC block.

[0040] In various embodiments, the method further comprises: providing an AC path through the first filter and a second filter; The relative delay between the DC path through the nothing. [Brief description of the drawings]

[0041] [Figure 1] FIG. 2 is a schematic diagram of a mobile device according to an embodiment. [Diagram 2] 1 is a schematic diagram of an envelope tracking system for a power amplifier according to one embodiment; [Figure 3A] FIG. 2 is a schematic diagram of an envelope tracking system for a power amplifier according to another embodiment. [Figure 3B] FIG. 2 is a schematic diagram of an envelope tracking system for a power amplifier according to another embodiment. [Figure 3C]FIG. 2 is a schematic diagram of an envelope tracking system for a power amplifier according to another embodiment. [Figure 3D] FIG. 2 is a schematic diagram of an envelope tracking system for a power amplifier according to another embodiment. [Figure 4] 1 is a graph of efficiency versus output power. [Diagram 5] FIG. 2 is a schematic diagram of an envelope tracking system for a power amplifier according to another embodiment. [Figure 6] FIG. 2 is a schematic diagram of an envelope tracking system for a power amplifier according to another embodiment. [Figure 7] FIG. 2 is a schematic diagram of a mobile device according to another embodiment. [Figure 8] FIG. 1 is a schematic diagram of an embodiment of a communication system for transmitting radio frequency (RF) signals. [Figure 9] FIG. 1 is a schematic diagram of a multi-level supply (MLS) modulation system according to an embodiment. [Figure 10] FIG. 1 is a schematic diagram of an MLS DC / DC converter according to an embodiment. [Figure 11] FIG. 1 is a schematic diagram of an example of timing for MLS DC / DC conversion. [Figure 12] FIG. 2 is a schematic diagram of an example of MLS envelope tracking for a continuous wave signal. [Figure 13] 3A-3C are schematic diagrams of examples of envelope frequency distributions of various signal waveforms; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The following detailed description of certain embodiments provides various descriptions of specific embodiments. However, the innovations described herein are, for example, as defined and covered by the claims. The present invention can be embodied in many different forms, as will be described in detail below. Reference is made to the drawings in which numerals indicate identical or functionally similar elements. It is to be further understood that elements illustrated in the drawings are not necessarily to scale. The embodiments may include more elements and / or portions of the elements shown in the drawings. Further, some embodiments may include any combination of features from two or more figures. It may also include a suitable combination.

[0043] Envelope tracking measures the power added efficiency (PAE) of a power amplifier relative to the amount of radiation it amplifies. Efficiently controls the voltage level of the power amplifier supply voltage in relation to the envelope of the line frequency (RF) signal. This is a technique that can be used to increase the power dissipation by controlling the RF As the signal envelope increases, the voltage supplied to the power amplifier may also increase. As the signal envelope decreases, the voltage supplied to the power amplifier also decreases, resulting in lower power consumption.

[0044] A multi-level envelope tracker generates two or more regulated voltages at different voltage levels. Multi-Level Supply (MLS) DC / DC converter and selective adjustment of the regulated voltage The MLS modulator outputs a reduced voltage, and the output of the MLS modulator is filtered to amplify the power. and a filter for generating a power amplifier supply voltage for the amplifier.

[0045] The multi-level envelope tracker provides dual DC and AC current measurements for the power amplifier supply voltage. The efficiency degradation occurs when the signal is circulated through the MLS modulator and / or common filter switches. For example, the switches of the modulator and / or the inductors of the filter may Power loss occurs in the DC resistance.

[0046] The DC resistance of the switch is low (e.g. a small percentage of the DC load of a power amplifier) Implementing the switch in this manner is not recommended, even though the switch can be implemented in a similar manner (as a This can result in a relatively large layout and / or significant switching losses. For example, when the desired source impedance is about 0.2 ohms, the switching The switch is constrained to achieve an on-state resistance of less than 0.2 ohms. A relatively large switch layout results.

[0047] A multi-level envelope tracking system with separate DC and AC paths is provided. In certain embodiments, an envelope tracking method is provided for generating a power amplifier supply voltage for a power amplifier. The envelope tracking system outputs a number of regulated voltages, A C / DC converter and an envelope signal corresponding to the envelope of the RF signal amplified by the power amplifier. an MLS modulator for controlling selection of the regulated voltage over time based on an AC path filter coupled between the output of the amplifier and the power amplifier supply voltage; and a DC path filter coupled between the power amplifier supply voltage.

[0048] Including a DC path through a DC path filter and a separate AC path through an AC path filter. By this, an improvement in the efficiency of the envelope tracking system can be achieved. For example, the DC current A low-frequency current such as ) thus relaxing the constraints on the size and / or DC resistance of the modulator switches. Therefore, low switching losses in the AC path can be achieved. In one example, the DC path is The tracking system delivers at least 75% of the energy that it provides to the power amplifier.

[0049] Since a high speed envelope signal may have energy content centered around DC, the DC path is It provides a highly efficient path for the high-frequency energy content. The filter is relatively small because the inductors in the filter can operate without DC saturation. In one example, the DC path filter may have a component size as large as the AC path filter. In one implementation, the AC path filter is implemented in less than half the size of a conventional AC path filter. A series DC blocking capacitor to help block DC current through the AC path filter Includes.

[0050] In certain implementations, the DC voltage is a regulated voltage from a DC / DC converter. For example, the MLS DC / DC converter can also be used to generate a DC voltage. In the illustrative embodiment, the voltage level of the DC voltage is a number of regulated voltages provided to the MLS modulator. may be the same as or different from one of the voltage levels.

[0051] FIG. 1 is a schematic diagram of a mobile device 70 according to an embodiment. , Primary antenna 1, Diversity antenna 2, Primary antenna tuning circuit 3, Di 4 versatile antenna tuning circuits, double-pole double-throw (DPDT) antenna diversity Switch 5, Primary Front-End Module 6, Diversity Front-End Module 7, battery 8, multi-level supply (MLS) envelope tracker 9, transceiver 10, baseband It includes a modem 11 and an application processor 12 .

[0052] Although one embodiment of a portable device is shown, the teachings herein may be used in a wide variety of configurations. The present invention is applicable to mobile devices implemented in a variety of ways. Therefore, other implementations are possible.

[0053] In the illustrated embodiment, the primary front-end module 6 includes a first power amplifier 21, A second power amplifier 22, a third power amplifier 23, a fourth power amplifier 24, and a first low noise amplifier 31 , a second low noise amplifier 32, a third low noise amplifier 33, a diplexer 42, a transmission / reception band switch switch 41, a transmission filter 43, a first duplexer 45, a second duplexer 46, a third duplexer a multiplexer 47, a first receiving filter 51, a second receiving filter 52, and a third receiving filter 53 , a first directional coupler 59, and a second directional coupler 60. Additionally, The front-end module 7 includes a first low-noise amplifier 35, a second low-noise amplifier 36, a first receiving a first reception filter 55, a second reception filter 56, a first reception band selection switch 61, and a second reception A band selection switch 62 is included.

[0054] Although one embodiment of a front-end circuit is shown, other embodiments of the front-end circuit may be used. For example, the front-end circuit may transmit and receive from one or more antennas. and / or a power amplifier (PA), low noise amplifier (LNA) for processing the received RF signal , filters, switches, phase shifters, duplexers, and / or other suitable circuits. Examples of front-end functions are signal amplification for transmission, signal amplification for reception, signal filtering, etc. switching between different bands, switching between different power modes, Switching between transmit and receive modes, duplexing signals, multiplexing signals diplexing or triplexing, or any combination of these This includes, but is not limited to:

[0055] Therefore, the primary front-end module, the diversity receiving front-end module Other implementations of the algorithm, antenna selection, and / or antenna tuning may also be used.

[0056] As shown in FIG. 1, the MLS envelope tracker 9 is a power amplifier in a mobile device 70. The device generates one or more power amplifier supply voltages for amplifying RF signals for wireless transmission purposes. In the illustrated embodiment, the MLS envelope tracker 9 receives battery power from the battery 8. Pressure V BATT , and a first power amplifier supply voltage V for the first power amplifier 21. PA1 , and and a second power amplifier supply voltage V for the first power amplifier 22. PA2 Generate the MLS envelope. Although an example is shown in which the line tracker 9 generates two power amplifier supply voltages, ML The S envelope tracker 9 may generate a power amplifier supply voltage that is greater or less than this.

[0057] The MLS envelope tracker 9 tracks the envelope of the first RF signal amplified by the first power amplifier 21. The first power amplifier supply voltage V PA1 Additionally, the MLS envelope tracker 9 The second power amplifier 22 is configured to track the envelope of the second RF signal that it amplifies. Supply voltage V PA2 In a given implementation, the MLS envelope tracker 9 controls the base The MLS envelope tracker 9 receives one or more envelope signals from a band modem 11. For example, the MLS envelope tracker 9 may A first envelope signal showing an envelope of the first RF signal and a second envelope signal showing an envelope of the second RF signal. The signal can be received.

[0058] Battery 8 includes, for example, a lithium ion battery for use in portable device 70. Any suitable battery may be used. Battery voltage V BATT is the DC / D C converter and used for multi-level envelope tracking according to the teachings herein. A regulated voltage is generated that is

[0059] The transceiver 10 generates an RF signal for transmission and transmits it to the primary antenna 1 and the diversity antenna 2. It processes the incoming RF signal received from antenna 2. It will be understood that the transmission of the RF signal The various functions associated with receiving and transmitting are collectively represented in FIG. This can be achieved by one or more components that are A separate component (e.g., a separate circuit or die) is provided to handle the RF signals of the This is also fine.

[0060] The baseband modem 11 transmits and receives signals to the transceiver 10 to generate RF signals for transmission. The baseband modem 11 also provides a digital representation of the transmit signal for processing by the transmitter 10. A receiver 10 processes a digital representation of the received signal.

[0061] As shown in FIG. 1, the baseband modem 11 is the primary application in the mobile device 70. The computer is coupled to an application processor 12 which is responsible for providing application processing. The application processor 12 handles memory management, graph processing, and / or multimedia. Suitable for supporting applications including but not limited to decoding A wide variety of functions can be provided, such as providing a variety of system capabilities.

[0062] Although the portable device 70 illustrates an example of a multi-level envelope tracker RF system. Regardless of the above, one or more multi-level envelope trackers implemented in accordance with the teachings herein may be used in a variety of applications. The NI 8111 can be included in a variety of RF systems.

[0063] 2-3C, 5 and 6 show various implementations of an envelope tracking system for a power amplifier. The present teachings, however, may be implemented in a wide variety of ways. It is applicable to envelope trackers, therefore other implementations are possible.

[0064] FIG. 2 is a schematic diagram of an envelope tracking system 100 for a power amplifier 71 according to one embodiment. FIG. 1 is a diagram showing an envelope tracking system 100 including an MLS DC / DC converter 72, a DC path filter The MLS DC / DC converter includes a converter 73, an MLS modulator 81, and an AC path filter 91. 72 is also called a switching regulator.

[0065] The power amplifier 71 receives an RF input signal RF IN is amplified to produce an RF output signal, RF OUT Generate The MLS modulator 81 receives an RF input signal RF IN The envelope signal varies relative to the envelope of (ENVELOPE). The envelope signal may be analog or digital.

[0066] In the illustrated embodiment, the MLS DC / DC converter 72 converts the battery voltage V BATT Received , various regulated voltages V MLSa , V MLSb , V MLSc , … V M LSnAlthough four MLS voltages are shown in the example, However, the MLS DC / DC converter 72 may have more than this, as indicated by the ellipsis. In this embodiment, the MLS DC / DC converter may generate a smaller or equal MLS voltage. The detector 72 also detects the battery voltage V BATT By adjusting the DC voltage V DC Also generates DC voltage V DC is the regulated voltage V MLSa , V MLSb , V MLSc , … V MLSn of It may be the same as or different from one of the voltage levels.

[0067] The MLS modulator 81 outputs the regulated voltage V MLSa , V MLSb , V MLSc , … V MLS n and envelope signals, and outputs the modulator output voltage to the AC path filter 91. In an exemplary implementation, the MLS modulator 81 selects an appropriate adjustment voltage over time based on the envelope signal. For example, the MLS modulator 81 controls the output voltage based on the selection of the envelope signal. Based on the value, the adjusted voltage V MLSa , V MLSb , V MLSc , … V MLSn Of to the output of the modulator.

[0068] The DC path filter 73 and the AC path filter 91 are each an MLS DC / DC converter. DC voltage V from the converter 72 DC and filtering the output of the MLS modulator 81. 7, which generates the power amplifier supply voltage VPA for the power amplifier 71.

[0069] Including a DC path through a DC path filter 73 and an AC path through an AC path filter 91 By doing so, it is possible to achieve improved efficiency of the envelope tracking system 100. For example, A frequency current (including but not limited to a DC current) is applied through a DC path filter 73. This relaxes the size and / or DC resistance constraints of the MLS modulator switches. can be done.

[0070] Therefore, low switching losses in the AC path can be achieved, and In one example, the DC path is an envelope tracking system. The system 100 delivers at least 75% of the energy that it provides to the power amplifier 71.

[0071] FIG. 3A is a schematic diagram of an envelope tracking system 140 for a power amplifier 101 according to another embodiment. The envelope tracking system 140 includes an envelope tracking integrated circuit (IC) 102 and a D A C path filter 103, an AC path filter 104, a DAC circuit 105, and an envelope filter The first decoupling capacitor 111 to the fourth decoupling capacitor 1 14 and an inductor 117.

[0072] Although an embodiment envelope tracking system is shown in FIG. , are applicable to envelope tracking systems implemented in a wide variety of ways. An implementation example is also possible.

[0073] In the illustrated embodiment, the envelope tracking IC 102 includes an MLS switching circuit 121 and , a digital control circuit 122, a baseband MLS modulator 123, and a modulator control circuit 124. The envelope tracking IC 102 of FIG. 3A includes, for example, a battery voltage (V BATT ) reception, Communication via Real Peripheral Interface (SPI), output of DC voltage VDC, Receives the envelope signal (ENVELOPE) and connects it to the decoupling capacitors 111 to 114. Various pins or pins for providing various functions, such as connection to the inductor 117, is depicted with pads. The envelope tracking IC is also referred to herein as an envelope tracking semiconductor die or Also called a chip.

[0074] MLS switching circuit 121 controls the current through inductor 117 to provide voltage regulation. For example, the MLS switching circuit 121 includes a switch and a controller. The controller may be any suitable modulation scheme (including but not limited to pulse width modulation). This switch is turned on and off using a scheme to provide DC / DC conversion. In an embodiment, the MLS switching circuit 121 has four adjustable inputs at different voltage levels. The adjusted MLS voltage and the adjusted DC voltage V DC However, the MLS switch The switching circuit 121 may be implemented to output a regulated voltage that is greater or less than this. This is also fine.

[0075] As shown in FIG. 3A, the MLS switching circuit 121 includes a digital control circuit 122. The digital control circuit 122 is controlled by the MLS switching circuit 121. Programmability, including but not limited to voltage level control of one or more regulated voltages output As shown in FIG. 3A, the digital The digital control circuit 122 is coupled to the SPI bus. In certain implementations, the digital control circuit 122 is a data input / output interface for data received via the SPI bus and / or other chip interfaces. The MLS switching circuit 121 is controlled based on the

[0076] The MLS switching circuit 121 may also be controlled by a modulator control circuit 124 . In one example, the regulated DC voltage V DC is at least partially controlled by the modulator control circuit 124. It is controlled by this.

[0077] The baseband MLS modulator 123 is coupled to the power amplifier supply through the AC path filter 104. Pressure V PA In certain implementations, the baseband MLS modulator 1 23 represents a switch coupled between each regulated MLS voltage and the AC path filter 104. Additionally, the switch of the modulator is controlled by the modulator controller 124 based on the envelope signal. The switch is selectively opened and closed by

[0078] In the illustrated embodiment, the DC path filter 103 includes a shunt capacitor 127 and Optionally, the AC path filter 104 includes a first series inductor 128. a first shunt capacitor 135, a second series inductor 132, a first shunt capacitor 135, and a second shunt An example implementation of the DC path filter and the AC path filter is shown in FIG. Although depicted, the teachings herein include DC path filters that may be implemented in a wide variety of ways. This is also applicable to the AC path filter and the inverter filter. Therefore, the filters of other implementation examples are also applicable to this. It can be used following the teachings therein.

[0079] In certain implementations, one or more components of the filter may be configured to provide flexibility and / or control. It is controllable (e.g., digitally programmable and / or analog) to enhance For example, in the illustrated embodiment, the first shunt capacitor The first shunt capacitor 135 and the second shunt capacitor 136 are controllable. Although two examples of filter components are shown, other filter components can be controlled. The present invention may additionally or alternatively be implemented so as to

[0080] FIG. 3B is a schematic diagram of an envelope tracking system 150 for a power amplifier 101 according to another embodiment. The envelope tracking system 150 of FIG. 3B is a schematic diagram of the envelope tracking system 140 of FIG. , but the envelope tracking system 150 is a different implementation of the AC path filter 144. It differs in that it includes

[0081] For example, compared to AC path filter 104 of FIG. 3A, AC path filter 104 of FIG. 44 further includes a DC block for blocking low frequency current through the AC path filter 144. In the illustrated embodiment, the DC blocking capacitor 138 includes 1 and 2. The input of the AC path filter 144 is coupled to the output of the AC path filter 144 .

[0082] The inclusion of DC blocking capacitor 138 provides low switching noise in the AC path. Since the loss of the signal can be reduced, the overall system efficiency can be improved. For example, the DC blocking capacitor 138 is connected to the AC path through the AC path filter 144. The energy carried by the DC path passes through a DC path filter 103. In one example, the DC path is a DC path fill. Filter 103a converts at least 75% of the energy provided by envelope tracking system 150 into power. The signal is conveyed to the amplifier 101 .

[0083] FIG. 3C is a schematic diagram of an envelope tracking system 160 for a power amplifier 101 according to another embodiment. The envelope tracking system 160 of FIG. 3C is a schematic diagram of the envelope tracking system 150 of FIG. , but the envelope tracking system 160 is a different implementation of the AC path filter 154. It differs in that it includes

[0084] For example, compared to AC path filter 144 of FIG. 3B, AC path filter 1 54 includes a DC blocking capacitor 138 coupled to the input of the filter. The capacitors are placed at various points in the AC path filter, for example at the input, The input and output may be included in the signal path.

[0085] FIG. 3D is a schematic diagram of an envelope tracking system 170 for a power amplifier 101 according to another embodiment. The envelope tracking system 170 of FIG. 3D is a schematic diagram of the envelope tracking system 140 of FIG. 1, except that the envelope tracking system 170 operates with two MLS regulated voltages. 1, the circuit tracer 102 is included. Additionally, a decoupling capacitor 113 and 114 has been omitted in view of the small number of MLS regulated voltages.

[0086] The envelope tracking system 170 of FIG. 3D has the advantage of being of reduced complexity. Additionally, the envelope tracking system 170 provides symbol tracking that may be suitable for high bandwidth modulation. Well suited for symbolic applications, e.g. by symbol tracing If symbols are used, the two MLS voltages are programmed to match the symbol rate (for example, 1 6 μs) can be used continuously. That is, the MLS modulator 123 is a power amplifier. Switch the voltage used to generate the device supply voltage to a new voltage holding capacitor The amount of data can be changed by tuning the

[0087] Use less filtering when using symbol by symbol tracking However, AC / DC division can still beneficially reduce the need for series switches. Sexuality is avoided.

[0088] Figure 4 shows a graph of efficiency versus output power. The graph shows the efficiency versus output power for different simulations. Includes three plots of efficiency vs. output power for the power amplifier and envelope tracker combination. For example, the first plot 171 shows a simulation with a 0.1 ohm switch resistance in the DC path. LTE Efficiency Plot 2, 172, with 1.0 Ohm Switch in DC Path 17 is a third plot 173 that includes a switch resistor. Improved efficiency may also be realized since low DC path resistance can be achieved through do.

[0089] Although a specific example of the simulation results of the envelope tracking system is shown in Fig. Other simulation results are possible. For example, the simulation results are operation parameters (including operating frequency), circuit topology, and / or fabrication process. This can vary based on a variety of factors, including but not limited to:

[0090] FIG. 5 is a schematic diagram of an envelope tracking system 180 for a power amplifier 71 according to another embodiment. 5 is a block diagram of an envelope tracking system 180 in accordance with the present invention, which is similar to the envelope tracking system 100 in accordance with the present invention. However, the envelope tracking system 150 further includes a controllable delay circuit 98 .

[0091] In the illustrated embodiment, the envelope tracking system 180 passes through the DC path filter 73. DC path delay t1 from the MLS DC / DC converter 72 to the supply input of the power amplifier 71 when Additionally, the envelope tracking system 180 operates with a controllable delay circuit 98, M The power from the MLS DC / DC converter 72 when passing through the LS modulator 81 and the AC path filter 91 5 operates with an AC path delay t2 from the input of the amplifier 71 to the supply input of the power amplifier 71.

[0092] The inclusion of a controllable delay circuit 98 increases the efficiency of the envelope tracking system 180. Thus, the relative delay between the AC and DC paths can be controlled. In this case, the delay of the controllable delay circuit 98 is set to the desired DC path delay t1 and AC path delay t2. , to substantially match the phase shift of the cascade to enhance efficiency.

[0093] For example, if there is no compensation for differential delay, the control bandwidth of the DC path is Due to the narrower width, the current in the AC path and the current in the DC path may compete with each other. In the example, the AC path is delayed by a controllable delay circuit 98 so that the load sees The relative delay of the DC paths is controlled. In a given implementation, the coupling occurs over a bandwidth. A phase shift of about 90 degrees results in relatively high efficiency. A digital state machine or other suitable control circuit controls the phase delay to achieve approximately 90 degrees. Acts as if giving.

[0094] FIG. 6 is a schematic diagram of an envelope tracking system 200 for a power amplifier 101 according to another embodiment. The envelope tracking system 200 of FIG. 6 is similar to the envelope tracking system 140 of FIG. Similarly, the envelope tracking system 200 may include different implementations of the envelope tracking IC 182. They differ in points.

[0095] For example, compared to the envelope tracking IC 102 of FIG. 3A, the envelope tracking IC 182 of FIG. In addition, the controllable delay buffers 191 to 194 are included. The functional delay buffers 191 to 194 are connected to the MLS switching circuit 121 to By providing a controllable delay in the cutoff voltage, the AC path delay is reduced relative to the DC path delay t1. The delay t2 is allowed to be adjusted relatively.

[0096] In this embodiment, the delay of the controllable delay buffers 191-194 is digitally controlled. Any variation in delay between the various MLS regulated voltage paths can be controlled by circuit 122. This increases the flexibility to take into account

[0097] FIG. 7 is a schematic diagram of a portable device 800 according to another embodiment. 0 includes a baseband system 801, a transceiver 802, a front-end system 803, Antenna 804, power management system 805, memory 806, user interface 807, and a battery 808.

[0098] The mobile device 800 may be a 2G, 3G, 4G (LTE, LTE Advanced, and LTE Advanced Pro), 5G, WLAN (e.g. Wi-Fi), WPAN (e.g. Blue tooth (registered trademark) and ZigBee (registered trademark), WMAN (e.g. WiMax ), and / or communicate using a wide variety of communication technologies, including but not limited to GPS technology. It can be used to believe.

[0099] The transceiver 802 generates RF signals for transmission and receives incoming signals from the antenna 804. Processes RF signals. It will be understood that the functions associated with transmitting and receiving RF signals are The various functions may be implemented by one or more components collectively represented in FIG. 7 as a transceiver 802. In one example, a device that is required to handle a given type of RF signal may be used. Alternatively, separate components (eg, separate circuits or dies) may be provided.

[0100] The front-end system 803 transmits to the antenna 804 and / or In the illustrated embodiment, the front The end system 803 includes a power amplifier (PA) 811, a low noise amplifier (LNA) 812, It includes a filter 813, a switch 814, and a duplexer 815. However, other An implementation example is also possible.

[0101] For example, the front-end system 803 amplifies a transmission signal, amplifies a reception signal, and Filtering, switching between different bands, switching between different power modes, Switching between transmit and receive modes, duplexing signals, multiplexing signals plexing (e.g. diplexing or triplexing), or any combination of these A number of functions can be provided, including but not limited to combinations of functions.

[0102] In certain implementations, the mobile device 800 supports carrier aggregation. This provides the flexibility to increase peak data rates. The system supports frequency division duplexing (FDD) and time division duplexing (TDD). Since it can be used for both, it can aggregate multiple carriers or channels (aggregation). Carrier aggregation is the process of linking multiple mobile stations within the same operating frequency band. This includes contiguous aggregation, where consecutive carriers are aggregated. Carrier aggregation is not contiguous. The carriers may be consecutive, or may include frequency separated carriers within a common band or within different bands.

[0103] The plurality of antennas 804 may include antennas used for a variety of different types of communications. For example, antenna 804 may receive signals associated with a wide variety of frequencies and communication standards. The radio frequency may include an antenna associated with transmitting and / or receiving the radio frequency.

[0104] In certain implementations, antenna 804 may be used for MIMO communications and / or switched diversity communications. For example, MIMO communication uses a single radio frequency channel. MIMO communication uses multiple antennas to communicate multiple data streams over a wireless High signal-to-noise ratio, improved code generation due to spatial multiplexing of the environment Benefit from reduced signal interference and / or better signal quality. refers to a communication in which a particular antenna is selected to operate at a particular time. A group of antennas may be selected based on various factors such as packet error rate and / or signal strength indicators. A switch can be used to select the antenna.

[0105] The mobile device 800 may operate with beamforming in certain implementations. For example, the front-end system 803 may include a variable phase Optionally, the phase shifter may include a phase shifter having a phase shifter 804. The antenna is controlled to provide beam forming and directionality for the transmission and / or reception of signals. For example, in the context of signal transmission, the phase of a transmit signal provided to antenna 804 may be 804 are coupled using constructive and destructive interference. Aggregated transmission exhibits a beam-like quality with strong signal strength that is controlled and propagates in a given direction. In the context of signal reception, phase refers to the time it takes for a signal to reach the antenna from a particular direction. 804 so that as much signal energy as possible is received. In one embodiment, the antenna 804 is configured to receive one or more arrays of signals to enhance beamforming. Includes an antenna element.

[0106] The baseband system 801 receives various user input / output (I / O) signals such as voice and data. The baseband system 80 is coupled to a user interface 807 that facilitates processing of the 1 provides the transceiver 802 with a digital representation of the transmitted signal, which the transceiver 802 processes. The baseband system 801 also includes a transceiver 802. As shown in FIG. 7, the mobile device also processes a digital representation of the received signal. The baseband system 801 is coupled to a memory 806 to facilitate operation of the system 800. .

[0107] The memory 806 may be used to facilitate operation of the mobile device 800 and / or to store user information. It can be used for a wide variety of purposes, such as storing data and / or instructions, to provide storage. It is possible.

[0108] The power management system 805 provides a number of power management functions for the mobile device 800. The force management system 805 may include an MLS envelope tracker implemented in accordance with one or more aspects of the present disclosure. 860.

[0109] As shown in FIG. 7, the power management system 805 receives the battery voltage from the battery 808. The battery 808 may be, for example, a lithium ion battery for use in the portable device 800. The battery may be any suitable battery, including a battery.

[0110] FIG. 8 is a schematic diagram of an embodiment of a communication system 950 for transmitting RF signals. The signal receiving system 950 includes a battery 901, an MLS envelope tracker 902, a power amplifier 903, a directional A differential coupler 904, a duplexing switching circuit 905, an antenna 906, a base Band processor 907, signal delay circuit 908, digital pre-distortion (DPD) Circuit 909, I / Q modulator 910, observation receiver 911, intermodulation detection circuit 912, envelope A delay circuit 921, a coordinate rotation digital calculation (CORDIC) circuit 922, a shaping circuit 923, It includes a digital-to-analog converter 924 and a reconstruction filter 925 .

[0111] The communication system 950 of FIG. 8 may be an envelope tracking system implemented in accordance with one or more aspects of the present disclosure. 1 shows an example of an RF system that may include a system. However, the teachings herein may be applied to a wide variety of The present invention is applicable to RF systems implemented in various ways.

[0112] The baseband processor 907 generates a sine wave or sinusoidal signal of the desired amplitude, frequency and phase. It operates to generate in-phase (I) and quadrature (Q) signals corresponding to the signal components. For example, the I and Q signals provide an equivalent representation of a sine wave. In a given implementation, the I signal The baseband processor 907 outputs the baseband signal and the Q signal in digital form. The baseband processor 90 may be any suitable processor for processing signals. 7 is a digital signal processor, microprocessor, programmable core, or It may include any combination of these.

[0113] A signal delay circuit 908 provides an adjustable delay to the I and Q signals and the envelope tracker 902 and R F signal RF IN The delay provided by the signal delay circuit 908 helps control the relative consistency between the The amount is controlled based on the amount of intermodulation in adjacent bands detected by intermodulation detection circuit 912.

[0114] The DPD circuit 909 digitally decodes the delayed I and Q signals from the signal delay circuit 908. Provides filter shaping and generates digitally predistorted (DPD) I and Q signals In the illustrated embodiment, the DPD provided by the DPD circuit 909 operates as follows: The DPD circuit 909 is controlled based on the amount of intermodulation detected by the intermodulation detection circuit 912. , reducing distortion of the power amplifier 903 and / or increasing the efficiency of the power amplifier 903. It plays an important role in adding value to the society.

[0115] The I / Q modulator 910 receives the digitally predistorted I and Q signals. These signals are then processed to generate the RF signal RFIN. For example, an I / Q modulator The 910 converts the digitally predistorted I and Q signals into analog form. and a DAC configured to up-convert the analog I and Q signals to radio frequency (RF). A mixer that downconverts the I and Q signals and combines them to produce an RF signal. No. RF IN In certain implementations, the I / Q modulator 910 may include a signal combiner. one or more filters configured to filter frequency components of a signal to be processed; may include.

[0116] The envelope delay circuit 921 delays the I and Q signals from the baseband processor 907. Additionally, a CORDIC circuit 922 processes the delayed I and Q signals, RF signal RF IN A digital envelope signal is generated that represents the envelope of the CORDI signal. Although one implementation using C circuit 922 is shown, the envelope signal may be obtained in other manners. It is also possible.

[0117] The shaping circuit 923 shapes the digital envelope signal to enhance the performance of the communication system 950. In certain implementations, the shaping circuit 923 operates to: A shaping table is included that maps each level to a corresponding shaped envelope signal level. The shaping helps to control the linearity, distortion, and / or efficiency of the power amplifier 903. obtain.

[0118] In the illustrated embodiment, the shaped envelope signal is converted to a differential analog signal by the DAC 924. Optionally, the differential analog envelope signal is a digital signal converted to a differential analog envelope signal. The differential envelope of the MLS envelope tracker 902 is filtered by the reconstruction filter 925. Differential envelope signals ENV_p, ENV_n suitable for use by the envelope amplifier are generated. In certain implementations, the reconstruction filter 925 includes a differential low-pass filter.

[0119] Although an example of envelope signaling is provided, the teachings herein may be implemented in a wide variety of manners. The present invention is also applicable to envelope signaling implemented in a multi-layered signal processing system. For example, in another embodiment, MLS envelope tracking is used. Priority is given to providing digital envelope data to the DAC 924 and reconstruction filter 902. Ruta 925 is omitted.

[0120] Continuing to refer to FIG. 8, the MLS envelope tracker 902 receives the signal from the reconstruction filter 925 as Receives the envelope signal and detects the battery voltage V BATT Receive the differential envelope signal The power amplifier supply voltage V for the power amplifier 903 is C C_PA Generate the power amplifier supply voltage V CC_PA is the RF signal IN In the envelope of The power amplifier 903 outputs the RF signal RF from the I / Q modulator 910. IN Received RF signal RF OUT In this example, a duplexing switching circuit The signal is applied to an antenna 906 via a line 905 .

[0121] The directional coupler 904 connects the output of the power amplifier 903 to the duplexing switching circuit. 905, a duplexing switching circuit 90 This allows measurement of the output power of the power amplifier 903, which does not include the insertion loss of the directional coupler 9 The detected output signal of the .04 is provided to an observation receiver 911. The observation receiver 911 A mixer that provides down-conversion to generate up-converted I and Q signals. and generating an I observation signal and a Q observation signal from the down-converted I signal and Q signal. and a DAC that configures the DAC.

[0122] The intermodulation detection circuit 912 couples the I and Q observation signals to the baseband processor 907. Optionally, an intermodulation detection circuit 912 determines intermodulation products with the I and Q signals from the The difference is calculated by controlling the DPD provided by the DPD circuit 909 and / or the delay of the signal delay circuit 908. Dynamic envelope signals ENV_p, ENV_n and RF signal RF IN Controls the relative consistency with In another embodiment, the intermodulation detection circuit 912 may additionally or alternatively include a signal delay circuit 92 Controls the delay of 1.

[0123] By including a feedback path from the output of the power amplifier 903 and the baseband , I and Q signals to optimize operation of the communication system 950. For example, by configuring the communication system 950 in this manner, it is possible to control power, It can help compensate for transmitter impairments and / or perform DPD.

[0124] Although shown as a single stage, power amplifier 903 may include one or more stages. Additionally, the teachings herein are applicable to communication systems that include multiple power amplifiers.

[0125] FIG. 9 is a schematic diagram of an MLS modulation system 1050 according to one embodiment. The modulation system 1050 includes a modulator control circuit 1020, an MLS DC / DC converter 1025, a converter a modulator switch bank 1027 and a decoupling capacitor bank 1030 .

[0126] The MLS modulation system 1050 of FIG. 9 is suitable for incorporation into a multi-level envelope tracker. An example of an implementation of a suitable MLS modulator circuit is shown below. However, it should be understood that the implementation may be implemented in accordance with the teachings herein. The multi-level envelope tracker may include other implementations of the MLS modulator circuit.

[0127] The MLS DC / DC converter 1025 converts the battery voltage V BATT By providing DC / DC conversion and based on the first regulated voltage V MLS1 , the second regulated voltage V MLS2 , and the third adjustment Voltage V MLS3 Although an example with three regulated voltages is shown, Instead, the MLS DC / DC converter 1025 may produce a regulated voltage that is greater or less than this. In certain implementations, at least a portion of the regulated voltage may be equal to the battery voltage V B ATT Additionally or alternatively, one or more of the regulated voltages may be boosted relative to the battery voltage. Pressure V BATT is the back voltage having a lower voltage than

[0128] The decoupling capacitor bank 1030 is generated by the MLS DC / DC converter 1025. For example, the decoupling capacitor bank in FIG. 1030 is the first adjustment voltage V MLS1 The first decoupling capacitor TA1031, second adjustment voltage V MLS2 A second decoupling capacitor that decouples the 1032, and the third adjustment voltage V MLS3 The third decoupling capacitor Includes Pacita 1033.

[0129] Continuing to refer to FIG. 9, the modulator switch bank 1027 switches the output of the modulator (MOD OUT ) and the first adjustment voltage V MLS1 a first switch 1041 connected between the Output of the device and the second adjustment voltage V MLS2 A second switch 1042 connected between the The modulator output and the third adjustment voltage V MLS3 and a third switch 1043 connected between the The modulator control unit 1020 selectively opens and closes the switches 1041 to 1043 to control the output of the modulator. Acts to control force.

[0130] FIG. 10 is a schematic diagram of an MLS DC / DC converter 1073 according to one embodiment. The LSDC / DC converter 1073 includes an inductor 1075, a first switch S1, a second switch switch S2, a third switch S3, a fourth switch S4, a fifth switch S5, and a sixth switch S 6. The MLS DC / DC converter 1073 further includes a switch that provides regulation of the opening and closing of the switch. 10. It also includes a control circuit (not shown in FIG. 10) for

[0131] The MLS DC / DC converter 1073 of FIG. 10 is incorporated into a multi-level envelope tracker. An example of an implementation of a MLS DC / DC converter suitable for use in this application is shown below. However, following the teachings herein, The multilevel envelope tracker implemented in this way includes other implementations of MLS DC / DC converters. That's fine.

[0132] In the illustrated embodiment, the first switch S1 is connected to the battery voltage V BATT Electrically connected to a first end of the second switch S2 and a first end of the inductor 1075 electrically connected to the first end of the second switch S2 and a second end connected to the first supply or the ground supply V G ND FIG. 10 shows a power supply using a ground supply and a battery voltage. Although the teachings herein show the configuration of a DC / DC converter powered by The invention is also applicable to DC / DC converters powered using any suitable power supply. The inductor 1075 further includes a first terminal of each of the third switch S3 to the sixth switch S6. The third switch S3 further includes a second end electrically connected to the ground supply V GND To The fourth switch S4, the fifth switch S5 and the sixth switch S6 also include a second terminal electrically connected thereto. Each of the S6 outputs the first regulated voltage V MLS1 , the second regulated voltage V MLS2 and 3 Regulated voltage V MLS3 and a second end configured to generate each of the

[0133] The first switch S1 to the sixth switch S6 adjust the regulated voltage to a specific error of the target voltage level. An example having three regulated voltages is shown. However, the MLS DC / DC converter 1073 may have more or less It may be implemented to generate a regulated voltage.

[0134] In the illustrated embodiment, the MLS DC / DC converter 1073 converts the battery voltage V BATT Yo and / or to generate a regulated boost voltage greater than the battery voltage V BATT than Operates as a buck-boost converter that can be used to generate a small regulated buck voltage However, other implementations are possible.

[0135] FIG. 11 is a schematic diagram of an example of timing for MLS DC / DC conversion. As shown in Fig. 1, the width of the regulation cycle is set to the regulation frequency generated by the MLS DC / DC conversion. For example, one MLS regulator can be used to control the voltage level of the applied voltage. the adjusted voltage is associated with a period t1, while the second adjusted voltage is associated with a different period t2. Additionally, non-overlapping can be used to avoid crowbar currents between different voltage levels. The period tovlp can also be used.

[0136] In certain implementations herein, one or more adjustment periods (e.g., t1 and / or t2) and and / or one or more of the non-overlapping periods (e.g., tovlop) can be digitally controlled. In one embodiment, the delay is controlled based on a digital state machine and / or other suitable circuitry. do.

[0137] The regulated voltage produced by the MLS DC / DC conversion is selectively varied by the modulator. In the illustrated example, the modulator output filter is The circuit is depicted as including shunt capacitors C1 and C2 and series inductors L1 and L2. However, other implementations of the modulator output filter are possible.

[0138] Provide both an AC path through the modulator output filter and a DC path that bypasses the modulator. For example, an envelope tracking system can be implemented in this manner to improve efficiency. By implementing this, the inductors of the modulator output filter (e.g., inductors L1 and / This reduction in energy can reduce the amount of energy stored in the This in turn can cause overshoot to the filter and / or return loop to the MLS switch. The bar current drops.

[0139] In one embodiment, an MLS DC / DC converter is used to modulate the power amplifier supply voltage. Two or more MLS voltages for the modulator and a power amplifier with a DC path that bypasses the modulator and a DC voltage that controls the supply voltage. Additionally, the DC voltage is adjusted to control the MLS voltage. For example, the adjustment period and / or the non-overlapping period used for adjustment are D The C voltage and the MLS voltage may be different. That is, the pulse width modulation (PWM) sequence may be different for the DC and AC paths.

[0140] FIG. 12 is a schematic diagram of an example of MLS envelope tracking for a continuous wave signal. An example is given for a continuous wave signal having a frequency of about 100 MHz and a corresponding period of about 10 ns. Examples of suitable MLS voltage levels for the signals are shown.

[0141] FIG. 13 is a schematic diagram of an example of envelope frequency distribution of various signal waveforms. For each type, the graph shows the DC envelope energy, the AC envelope energy below 1MHz The modulator output filter plots the percentage of AC envelope energy above 1MHz. By providing both an AC path through the filter and a DC path that bypasses the modulator, The efficiency of various types of RF signal waveforms is improved.

[0142] Conclusion

[0143] Some of the above embodiments have given examples relating to mobile devices. The principles and advantages of these embodiments may be applied to any other system or It can be used for the device.

[0144] Unless the context clearly requires otherwise, In this regard, the words "including," "comprises," and the like are used in an inclusive sense as opposed to an exclusive or exhaustive sense. In general, the term "including but not limited to" should be interpreted as meaning "including but not limited to" The term "coupled" as used herein means that two or more elements are directly connected or connected via one or more interconnects. It is noted here that the two components may be connected via an inter-connection element. The term "connected," as used generally, also means that two or more elements are directly connected or that one or more elements are connected by a It is noted that the present application may either be connected via an intermediate element or When used herein, the terms "herein," "upper," "lower," and words of similar import shall mean the same things as used herein. This application is hereby incorporated by reference in its entirety and not to any particular portions thereof. Where permitted, terms in the above Detailed Description using singular or plural numbers shall The terms "or" and "if" refer to a list of two or more items. The term "or" means any of the items in a list, Covers all of the items in the list, and any combination of the items in the list. .

[0145] Furthermore, unless specifically stated or understood otherwise within the context of use, Insofar as possible, the following terms are used in particular: "can," "might," "may," "may," "for example," "may Conditional language used herein, such as "such as," "such as," "such that ... It is intended that certain embodiments include certain features, elements, and / or conditions while other embodiments do not. That is, such conditional language generally indicates that the features, elements and / or states are consistent with one or more implementations. The presence of any aspect necessary for the form or the existence of one or more embodiments of the invention without the input of the authors or includes these features, elements and / or conditions, with or without prompts. The logic that determines whether or not a It is not intended to imply necessarily inclusive.

[0146] The above description of embodiments of the present invention is not intended to be exhaustive or to be construed as limiting the scope of the present invention. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Although the embodiments and examples have been described above for illustrative purposes, those skilled in the art will recognize that the present invention Various equivalent modifications are possible within the scope. For example, the processes or blocks may be arranged in a given order. While presented herein, alternative embodiments may perform routines having steps in a different order. can use a system having blocks, some processes or blocks being These processes or blocks may be deleted, moved, added, subdivided, combined and / or modified. Each of the blocks may be implemented in a variety of different ways. While these processes or blocks may be shown as being executed in a sequence, Alternatively, they may be performed in parallel, or at different times.

[0147] The teachings of the present invention provided herein may be used in conjunction with other systems, not necessarily the systems mentioned above. The elements and operations of the various embodiments described above may be implemented in further embodiments. They may be combined to give form.

[0148] While certain embodiments of the present invention have been described, it will be understood that these embodiments are presented by way of example only. and are not intended to limit the scope of the present disclosure. Indeed, The novel methods and systems may be embodied in a variety of other forms and may be implemented in any manner that is consistent with the teachings set forth herein. Various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit and scope of the present disclosure. The appended claims and their equivalents are intended to be construed as falling within the scope and spirit of the present disclosure. It is intended to cover such forms or modifications as may come within the scope of the present invention.

Claims

1. 1. An envelope tracking system comprising: A power amplifier configured to amplify a radio frequency signal and to receive power from a power amplifier supply voltage. a power amplifier formed by adjusting the power amplifier supply voltage based on an envelope signal corresponding to an envelope of the radio frequency signal; an envelope tracker configured to generate Including, The envelope tracker comprises: a DC / DC converter configured to output a plurality of regulated voltages; generating a modulator output voltage based on the plurality of regulated voltages and the envelope signal; a modulator formed by a first filter coupled between the modulator output voltage and the power amplifier supply voltage; a second filter coupled between the DC voltage and the power amplifier supply voltage; An envelope tracking system comprising:

2. The package of claim 1 , wherein the DC / DC converter is further configured to generate the DC voltage. Tangle tracing system.

3. 2. The envelope tracking method of claim 1, wherein the plurality of regulated voltages each have a different voltage level. system.

4. The modulators each select a corresponding one of the modulator output voltages and the plurality of regulated voltages.

2. The envelope tracking system of claim 1, further comprising a plurality of switches coupled between a single regulated voltage. system.

5. The first filter includes at least one series inductor and at least one shunt inductor.

2. The envelope tracking system of claim 1, further comprising:

6. The first filter is further connected in series between the modulator output voltage and the power amplifier supply voltage.

6. The envelope tracking system of claim 5, further comprising a DC blocking capacitor connected to said first input.

7. The second filter includes at least one series inductor and at least one shunt capacitor.

2. The envelope tracking system of claim 1, further comprising:

8. The envelope tracker further comprises an AC path through the first filter and an AC path through the second filter. a controllable delay circuit configured to control the relative delay between the DC path and the The envelope tracking system of Item 1.

9. The controllable delay circuits each adjust a corresponding one of the plurality of regulated voltages. a plurality of controllable delay buffers configured to control the delay of the saved voltage. 8 envelope tracking system.

10. A DC path through the second filter is provided from the envelope tracker to the power amplifier.

10. The envelope tracking system of claim 1, wherein the envelope tracking system conveys at least 75 percent of the energy.

11. 1. A mobile device comprising: a transceiver configured to generate a radio frequency transmit signal; a power amplifier for amplifying said radio frequency transmit signal and receiving power from a power amplifier supply voltage; a front-end circuit including a power amplifier configured to The power amplifier supply voltage is adjusted based on an envelope signal corresponding to the envelope of the radio frequency transmission signal. a power management circuit including an envelope tracker configured to generate a Including, The envelope tracker comprises: a DC / DC converter configured to output a plurality of regulated voltages; generating a modulator output voltage based on the plurality of regulated voltages and the envelope signal; a modulator formed by a first filter coupled between the modulator output voltage and the power amplifier supply voltage; a second filter coupled between the DC voltage and the power amplifier supply voltage; , including mobile devices.

12. 12. The method of claim 11, wherein the DC / DC converter is further configured to generate the DC voltage. Mobile devices.

13. further comprising a battery for providing the battery voltage; The DC / DC converter provides a DC / DC conversion of the battery voltage based on the multiple 12. The portable device of claim 11, configured to generate a number of regulated voltages and the DC voltage. vinegar.

14. The first filter is at least one series inductor; at least one shunt capacitor; A DC blocking capacitor in series between the modulator output voltage and the power amplifier supply voltage. Ta and The mobile device of claim 11 , comprising:

15. The envelope tracker further comprises: an AC path through the first filter and the second filter; a controllable delay circuit configured to control a relative delay between a DC path through which the The mobile device of claim 1.

16. The controllable delay circuits each adjust a corresponding one of the plurality of regulated voltages. a plurality of controllable delay buffers configured to control the delay of the saved voltage. 15 mobile devices.

17. 1. A method of envelope tracking comprising: amplifying a radio frequency signal using a power amplifier; powering the power amplifier using a power amplifier supply voltage; outputting a plurality of regulated voltages from the DC / DC converter; Using a modulator, a modulator output voltage is adjusted based on the plurality of regulated voltages and the envelope signal. generating an envelope signal corresponding to an envelope of the radio frequency signal; 、 using a first filter present between the modulator output voltage and the power amplifier supply voltage controlling the power amplifier supply voltage; A second filter is used between the DC voltage and the power amplifier supply voltage. Controlling the amplifier supply voltage; A method comprising:

18. 18. The method of claim 17, further comprising generating the DC voltage using the DC / DC converter. How to.

19. providing DC blocking using a series DC blocking capacitor in said first filter; 20. The method of claim 17, further comprising:

20. A controllable delay circuit is used to separate the AC path through the first filter and the AC path through the second filter.

20. The method of claim 17, further comprising controlling a relative delay between a DC path and a DC path having a different delay than the first DC path.

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