High-bandwidth envelope tracking power supply adopting high-order filter

Abstract

The invention discloses a high-bandwidth envelope tracking power supply adopting a high-order filter, which is characterized by comprising a step wave voltage generation circuit, a high-order filter circuit and a high-frequency compensation circuit. The step wave voltage generation circuit generates step wave voltage to perform preliminary fitting on an envelope signal; the high-order filter circuit adopts a high-order LC low-pass filter structure, so that high-frequency harmonic components in step waves are effectively filtered, and a voltage signal closer to an envelope signal is further obtained; and calculating a difference value between a result obtained in the previous step and a reference signal through a high-frequency compensation circuit, processing the difference value through a PID (Proportion Integration Differentiation) controller, transmitting the processed difference value to a linear amplifier for power amplification, and finally compensating to a load. According to the envelope tracking power supply, the current passing through the linear amplifier is reduced, the loss of the linear amplifier is reduced, and the efficiency of the envelope tracking power supply is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication, and in particular, to a high-bandwidth envelope tracking power supply using a high-order filter. Background Art

[0002] Mobile communication, as a modern technology of wireless communication, has developed rapidly since the 1970s and can be basically divided into five generations so far. As of the end of November 2020, the scale of mobile phone users in China exceeded 1.6 billion, among which the scale of the fourth-generation (4th Generation, 4G) mobile communication users was 1.276 billion, accounting for 79.7% of mobile phone users, and the proportion has been steadily increasing. At present, the world has entered the fifth-generation (5th Generation, 5G) mobile communication. By 2024, 35% of the global mobile data traffic will be borne by 5G networks. From the first generation to the fifth generation, the progress of mobile communication technology has driven global economic development, influenced the trend of high-tech industries, and changed people's lifestyles, but at the same time, it has also brought huge energy consumption.

[0003] The first-generation (1st Generation, 1G) mobile communication uses the cellular network technology of analog circuits. Its main implementation methods are frequency division multiple access and carrier multiplexing. The transmission signal error rate is high and digital information cannot be transmitted. The second-generation (2nd Generation, 2G) mobile communication uses digital modulation methods to perform frequency and phase modulation on the radio frequency (Radio Frequency, RF) input signal, and can transmit information such as voice and text, but the data transmission rate is relatively low. In the first-generation and second-generation mobile communication technologies, the envelope amplitude of the input signal is constant, and a nonlinear power amplifier (Power Amplifier, PA) with constant voltage power supply can be used to amplify the RF input signal. However, in the third-generation (3rd Generation, 3G) and 4G mobile communication technologies, the amplitude of the RF signal represented by the orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) envelope signal is non-constant and has a high peak-to-average power ratio (Peak-to-Average Power Ratio, PAPR).

[0004] When the envelope voltage of the RF signal is not constant, if the constant voltage power supply method is used, the voltage difference between the power supply voltage and the RF signal envelope is large, and the efficiency is low. However, if the envelope tracking power supply method is used, the voltage difference between the power supply voltage and the RF signal envelope can be effectively reduced, so as to greatly reduce losses and improve efficiency.

[0005] At present, there are mainly three ways to achieve high-efficiency operation of PA, namely Doherty technology, Envelope Elimination and Restoration (EER) technology, and Envelope Tracking (ET) technology. Among them, Doherty technology requires the coordinated operation of primary and secondary power amplifiers, with a high cost and a low working bandwidth; EER technology uses a non-linear power amplifier, and the output voltage of the envelope restoration link needs to be exactly the same as the envelope amplitude of the input signal, which is more stringent for the power supply requirements of the power amplifier; in ET technology, the envelope output voltage tracks the RF reference signal and is slightly higher than the envelope of the RF reference signal, and the power supply method of the PA is not as stringent as the power supply requirement in EER technology. Therefore, ET technology has better application prospects and implementation methods, and currently common ET power supplies usually use a switched converter in series with a linear power supply to obtain a higher linearity output signal. However, although the voltage borne by the linear amplifier is effectively reduced, it still passes through all the load current, so the loss is large, resulting in a reduction in the efficiency of the entire ET power supply system. Summary of the Invention

[0006] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title, but such simplifications or omissions shall not be used to limit the scope of the present invention.

[0007] In view of the above existing problems, the present invention is proposed.

[0008] Therefore, the technical problem solved by the present invention is: to provide an envelope tracking power supply with high bandwidth using a high-order filter, which reduces the current passing through the linear amplifier and solves the problem of excessive loss of the linear amplifier in the envelope tracking power supply.

[0009] To solve the above technical problem, the present invention provides the following technical solutions: a staircase wave voltage generation circuit, a high-order filter circuit, and a high-frequency compensation circuit; the staircase wave voltage generation circuit includes a level providing unit and a gating switch unit; the high-order filter circuit is composed of a high-order LC low-pass filter circuit; the high-frequency compensation circuit includes a differential amplifier circuit, a PID controller, a linear amplifier, and a high-pass filter circuit.

[0010] As a preferred embodiment of the high-bandwidth envelope tracking power supply using a high-order filter according to the present invention, further comprising: the stepped wave voltage generating circuit includes a level providing unit and a gating switch unit. The level providing unit is composed of m independent voltage sources V1, V2, …, Vm or is formed by series superposition of m equivalent voltage sources. Among them, the output voltage values of the voltage sources are configured based on the amplitude characteristics of the target envelope signal, specifically, the peak voltage of the envelope signal is divided into m voltage intervals; the gating switch unit is turned on in a preset order to sequentially connect the m voltage sources to the output circuit, thereby generating a stepped wave output voltage matching the waveform of the envelope signal.

[0011] As a preferred embodiment of the high-bandwidth envelope tracking power supply using a high-order filter according to the present invention, further comprising: the high-order filter circuit includes filter inductors L1, filter capacitors C1, …, filter inductors Ln, filter capacitors Cn. For the low-pass filter formed by L1, C1, …, Ln, Cn, it has certain amplitude-frequency characteristics and phase-frequency characteristics. Based on the characteristics of the envelope signal to be tracked, parameters such as the desired damping ratio, cut-off frequency, and attenuation multiple at a specific frequency are set, and then the values of the parameters of each component required can be obtained through calculation.

[0012] As a preferred embodiment of the high-bandwidth envelope tracking power supply using a high-order filter according to the present invention, further comprising: the high-frequency compensation circuit includes a differential amplifier circuit, a PID controller, a linear amplifier, and a high-pass filter circuit. The differential amplifier circuit calculates the difference between the signal obtained by filtering the stepped wave sent by the stepped wave voltage generating circuit through the high-order filter circuit and the reference signal. The obtained difference result is processed by the PID controller and then power-amplified by the linear amplifier; the high-pass filter circuit then performs high-pass filtering on the output result of the linear amplifier to filter out the lower-frequency part and finally compensate it to the original load.

[0013] Advantages of the present invention: Compared with a general envelope tracking power supply, the high-bandwidth envelope tracking power supply using a high-order filter, when tracking a high-bandwidth envelope signal, filters the stepped wave signal through the high-order filter unit, performs differential amplification on the filtered result and the reference signal, and then sends it into the linear amplifier. Since the filtered signal is relatively close to the reference signal, the current passing through the linear amplifier after differential amplification is also small, the loss of the linear amplifier is small, and the overall efficiency of the system is improved; at the same time, the stepped wave voltage generating circuit is retained to achieve the effect of reducing the switching frequency, improving the reliability of the system, and truly realizing high-bandwidth envelope tracking. Description of the Drawings

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings. Among them:

[0015] Figure 1 FIG. 4 is a schematic circuit diagram of a high-bandwidth envelope tracking power supply using a high-order filter according to an embodiment of the present invention;

[0016] Figure 2 (a) FIG. 8(a) shows a stepped wave signal V generated by a stepped wave voltage generating circuit when a high-bandwidth envelope tracking power supply using a high-order filter according to an embodiment of the present invention tracks a 5 MHz OFDM signal, mul for a preliminary fitting of the OFDM signal; Figure 2 (b) FIG. 8(b) is a waveform diagram of the result v obtained after filtering the stepped wave voltage signal v mul through a high-order filter; fil ;

[0017] Figure 3 (a) FIG. 20(a) shows a reference signal v when a high-bandwidth envelope tracking power supply using a high-order filter according to an embodiment of the present invention tracks an OFDM signal, ref , Figure 3 (b) FIG. 20(b) is a waveform diagram of v obtained after filtering the stepped wave signal v mul through a high-order filter, fil ; Figure 3 (c) FIG. 20(c) is a waveform diagram of the differential result between the reference signal v ref and the filtered signal v fil ; Detailed Embodiments

[0018] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed embodiments of the present invention in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0020] Second, as used herein, "one embodiment" or "an embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that exclude each other with other embodiments.

[0021] The present invention will be described in detail with reference to the schematic diagrams. When describing the embodiments of the present invention in detail, for the convenience of explanation, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0022] At the same time, in the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper, lower, inner, and outer" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first, second, or third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0023] Unless otherwise clearly defined and limited in the present invention, the terms "mounted, connected, and coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may also be a mechanical connection, an electrical connection, or a direct connection, or may be indirectly connected through an intermediate medium, or may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Embodiment 1

[0025] Referring to Figure 1 , for an embodiment of the present invention, there is provided a high-bandwidth envelope tracking power supply using a high-order filter, including:

[0026] A staircase voltage generation circuit, a high-order filter circuit, and a high-frequency compensation circuit; wherein, the staircase voltage generation circuit is composed of a level providing unit and a gating switch unit; the high-order filter circuit is composed of an inductor and a capacitor; the high-frequency compensation circuit is composed of a differential amplifier circuit, a PID controller, a linear amplifier, and a high-pass filter circuit.

[0027] Specifically, the staircase wave voltage generating circuit includes a level providing unit and a gating switch unit. The level providing unit is composed of m mutually independent voltage sources V1, V2, …, Vm or is formed by series superposition of m equivalent voltage sources. The output voltage values of each voltage source are configured based on the amplitude characteristics of the target envelope signal, specifically by dividing the peak voltage of the envelope signal into m voltage intervals; the gating switch unit conducts in a preset order, and sequentially connects the m voltage sources to the output loop, thereby generating a staircase wave output voltage that matches the waveform of the envelope signal.

[0028] Furthermore, the high-order filter circuit is composed of inductors L1, …, Ln and capacitors C1, …, Cn. After determining the high-bandwidth envelope signal to be tracked, by selecting parameters such as the cut-off frequency, damping ratio, and attenuation multiple at specific frequency components, the values of L1, C1, …, Ln, Cn are solved to achieve the desired filtering effect.

[0029] Furthermore, the high-frequency compensation circuit is composed of a differential amplifier circuit, a PID controller, a linear amplifier, and a high-pass filter circuit. After filtering by the high-order filter circuit, some high-frequency harmonics in the staircase wave voltage signal generated by the staircase wave voltage generating circuit will be filtered out, but there will still be high-frequency components remaining. Therefore, the difference between the voltage signal filtered by the high-order filter and the reference signal is calculated by the differential amplifier circuit, and then processed by the PID controller and sent to the linear amplifier for power amplification; then the lower-frequency signals in the amplified result are filtered out by the high-pass filter circuit and compensated to the original load.

[0030] It should be noted that for the selection of high-order filter parameters, attention should be paid to:

[0031] The passband of the filter should be as flat as possible and the attenuation multiple should be 0 dB to ensure that the signals to be retained can be retained as completely as possible;

[0032] The selection of the damping ratio of the filter should ensure that the overshoot is as small as possible;

[0033] The set cut-off frequency of the filter should be lower than the switching frequency to filter out each harmonic component of the switch.

[0034] As can be seen from the above description, the method of the present invention has the following advantages: The proposed high-bandwidth tracking power supply using a high-order filter makes improvements on the basis of the conventional envelope tracking power supply. The staircase wave voltage signal is filtered by the high-order filter, and the filtered result is differentially amplified with the reference signal. Since the filtered signal is close to the reference signal, the current passing through the linear amplifier after differential amplification is also small, and the loss of the linear amplifier is small. It not only retains the advantage of the staircase wave voltage generating circuit in reducing the switching frequency but also reduces the loss of the linear amplifier and improves the overall efficiency of the system.

[0035] It should be recognized that embodiments of the present invention can be implemented or carried out by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The methods can be implemented in a computer program using standard programming techniques - including a non-transitory computer-readable storage medium configured with the computer program, wherein the storage medium so configured causes the computer to operate in a specific and predefined manner - in accordance with the methods and drawings described in the specific embodiments. Each program can be implemented in a high-level procedural or object-oriented programming language to communicate with a computer system. However, if desired, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. Additionally, for this purpose the program is capable of running on a programmed application specific integrated circuit.

[0036] Furthermore, the operations of the processes described herein can be performed in any suitable order, unless otherwise indicated herein or otherwise clearly contradicted by the context. The processes described herein (or variations and / or combinations thereof) can be performed under the control of one or more computer systems configured with executable instructions and can be implemented as code (e.g., executable instructions, one or more computer programs, or one or more applications) collectively executed on one or more processors, by hardware, or by a combination thereof. The computer programs include a plurality of instructions executable by one or more processors.

[0037] Further, the method can be implemented in any type of computing platform operatively connected to a suitable one, including but not limited to personal computers, minicomputers, mainframes, workstations, network or distributed computing environments, separate or integrated computer platforms, or communicating with charged particle tools or other imaging devices, etc. Aspects of the present invention can be implemented in machine-readable code stored on a non-transitory storage medium or device, whether removable or integrated into the computing platform, such as a hard disk, optical read and / or write storage medium, RAM, ROM, etc., such that it can be read by a programmable computer and, when read by the storage medium or device, can be used to configure and operate the computer to perform the processes described herein. Additionally, the machine-readable code, or portions thereof, can be transmitted via a wired or wireless network. When such media includes instructions or programs that implement the above-described steps in conjunction with a microprocessor or other data processor, the invention described herein includes these and other different types of non-transitory computer-readable storage media. When programmed according to the methods and techniques of the present invention, the present invention also includes the computer itself. A computer program is capable of applying to input data to perform the functions described herein, thereby transforming the input data to generate output data stored in non-volatile memory. The output information can also be applied to one or more output devices such as a display. In a preferred embodiment of the present invention, the transformed data represents physical and tangible objects, including a specific visual depiction of the physical and tangible objects generated on a display.

[0038] As used in this application, the terms "component", "module", "system", etc. are intended to refer to a computer-related entity, which can be hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to: a process running on a processor, a processor, an object, an executable file, a thread in execution, a program, and / or a computer. As an example, an application running on a computing device and the computing device can both be components. One or more components can exist in a process and / or thread in execution, and the components can be located in one computer and / or distributed between two or more computers. Additionally, these components can execute from various computer-readable media having various data structures thereon. These components can communicate in a local and / or remote procedure manner via signals such as according to one or more data packets (e.g., data from one component that interacts with another component in a local system, a distributed system, and / or communicates with other systems via a network such as the Internet in a signal manner).

[0039] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A high-bandwidth envelope tracking power supply using a high-order filter, characterized in that: include: Step wave voltage generating circuit, high-order filter circuit and high-frequency compensation circuit; The step wave voltage generating circuit comprises a level providing unit and a gate switch unit; The high-order filter circuit includes a passive filter composed of capacitors and inductors; The high-frequency compensation circuit includes a differential amplifier circuit, a PID controller, a linear amplifier, and a high-pass filter circuit.

2. The high-bandwidth envelope tracking power supply using a high-order filter as claimed in claim 1, characterized in that: Also includes, The step wave voltage generating circuit includes a level providing unit and a gate switch unit. The level providing unit is composed of m mutually independent voltage sources V1, V2, ..., Vm or m equivalent voltage sources connected in series, wherein the output voltage value of each voltage source is configured based on the amplitude characteristics of the target envelope signal, specifically, the peak voltage of the envelope signal is divided into m voltage intervals; the gate switch unit is turned on in sequence according to a preset order, and the m voltage sources are connected to the output circuit in sequence, thereby generating a step wave output voltage matching the waveform of the envelope signal.

3. The high-bandwidth envelope tracking power supply using a high-order filter as claimed in claim 1, characterized in that: Also includes, The high-order filter includes a filter inductor L1, a filter capacitor C1, ..., a filter inductor Ln, and a filter capacitor Cn. The values ​​of the filter inductor L1, ..., Ln and the filter capacitor C1, ..., Cn are determined by the tracked envelope signal, and the cutoff frequency of the high-order filter is determined according to the bandwidth of the envelope signal.

4. The high-bandwidth envelope tracking power supply using a high-order filter as claimed in claim 1, characterized in that: Also includes, The high-frequency compensation circuit includes a differential amplifier circuit, a PID controller, a linear amplifier and a high-pass filter circuit. The differential amplifier circuit performs differential calculation on the result after filtering by the high-order filter and the reference signal, sends the calculated result to the PID controller and then performs power amplification processing via the linear amplifier, and then filters the lower frequency components of the amplified output result through a high-pass filter, and finally compensates the result to the load to realize the high-frequency compensation function. A computing device comprising: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of a high-bandwidth envelope tracking power supply using a high-order filter as described in any one of claims 1 to 4 are implemented. A computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, implement the steps of a high-bandwidth envelope tracking power supply using a high-order filter as described in any one of claims 1 to 4.

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