WO2012068823A1

WO2012068823A1 - Power modulator

Info

Publication number: WO2012068823A1
Application number: PCT/CN2011/073022
Authority: WO
Inventors: 王林国; 张滨
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-11-25
Filing date: 2011-04-19
Publication date: 2012-05-31
Also published as: CN102478873A; CN102478873B

Abstract

A power modulator is provided, which includes: a switching mode power regulator (301) and a linear power regulator (302) which are connected in parallel. After the input reference signal (305) to be tracked is regulated by the said switching mode power regulator and linear power regulator, a total output voltage (306) is composed by the output voltages (303, 304) of the switching mode power regulator and the linear power regulator. The said linear power regulator is powered by a non-DC supply. The non-DC supply for the power modulator replaces the DC supply of the prior art, which causes that the supply voltage for the linear power regulator varies with the signal voltage. Therefore the power efficiency of the power modulator is improved.

Description

Power supply modulator

The present invention relates to the field of electronic technologies, and in particular, to a power supply modulator. Background technique

In electronic devices, voltage modulation is required in a variety of situations, and a typical one is a power supply device for an RF power amplifier.

In response to the increasing user demand for bandwidth, the modulation scheme of communication systems has become more and more complicated. One of the outstanding problems is the inefficiency of RF power amplifiers, which has become a bottleneck for improving the efficiency of the entire communication system. For linear power amplifiers, to ensure linearity, in the traditional DC power supply mode, the supply voltage needs to be higher than the peak value of the RF signal. When the amplitude of the RF signal is low, the power amplifier is subjected to higher voltage and load current at the same time, so the efficiency is lower. The average efficiency of the power amplifier depends on the peak-to-average power ratio (PAPR) of the RF signal. In order to obtain the maximum communication bandwidth in a limited frequency band, modern communication systems use a non-constant envelope (amplitude) and a high peak-to-average ratio modulation. For example, the peak of the modulated signal in the WCDMA (Wideband Code Division Multiple Access) system The ratio is 6.5db~7.0dB, and the next-generation network LTE (Long Term Evolution) and the OFDMA (Orthogonal Frequency-Division Multiple Access) system used by WiMax have a peak-to-average ratio of 9.0dB~9.5dB, resulting in power amplifier efficiency. This also brings a series of other problems such as increased power amplifier volume and weight, higher air conditioning and other cooling environment requirements, etc., which increases application and maintenance costs. Therefore, improving the efficiency of power amplifiers has great practical significance. .

In the existing literature and technology, power amplifier efficiency improvement schemes relying on power supply technology mainly include: Envelope Elimination and Restoration (EE), and Envelope Tracking (ET) power supply. Where the envelope separation and recovery technique utilizes a constant envelope The signal can be efficiently amplified by a nonlinear power amplifier, and the RF signal to be amplified is separated into an envelope and a phase modulated signal, and the amplified power RF signal is restored by an envelope tracking power supply to the nonlinear power amplifier. Since the amplified signal amplitude is determined by the envelope tracking power supply output voltage amplitude, the tracking accuracy of the envelope tracking power supply is high, otherwise the linearity of the amplified signal is affected. The envelope tracking power supply method uses a linear power amplifier to dynamically adjust the supply voltage by tracking the envelope signal to improve the efficiency of the linear power amplifier. Both solutions require dynamic modulation of the output voltage of the power supply. The power modulator must ensure high efficiency at the same time to ensure the efficiency of the two schemes for the entire power amplifier system.

In the modern communication system, the RF envelope signal has a high bandwidth, for example, the WCDMA single carrier is 5 MHz, and the 4 carrier is 20 MHz. The envelope tracking power supply needs to provide high modulation bandwidth and efficiency. In the prior art, the switching power supply regulator can provide high conversion efficiency. However, in applications that satisfy high bandwidths such as 20 MHz, extremely high switching speeds are required, which cannot be achieved by existing switching devices, and the conversion efficiency of the regulators is thus lowered.

In another prior art, the multi-level output mode can reduce the switching speed of the switch, such as the Class-G mode by switching multiple input voltages. FIG. 1 is a switching power supply regulator of the prior art. Schematic diagram of the structure, as shown in Fig. 1, obtains a plurality of tracking levels 104, and does not require a coupling device such as an inductor, and the bandwidth can be greatly improved. Since the high-efficiency DC voltage sources 101, 102, and 103 are directly cut, the efficiency is also high. However, under the constraints of the switching speed and switching loss of the existing switching devices, the existing switching multi-level scheme adopts an open loop method, and the tracking precision is low. In addition, there is an inevitable switching ripple, which further reduces the tracking accuracy. Therefore, the further improvement of the switching high-bandwidth power conditioner is combined with the linear power regulator. Figure 2 shows the switching power supply adjustment in the prior art. A schematic diagram of the combined structure of the linear power regulator and the linear power regulator, as shown in FIG. 2, provides smooth switching and high tracking accuracy through the negative feedback control of the linear power regulator 202.

However, in the prior art in which a switching power supply regulator is combined with a linear power regulator, Linear power regulators are also traditionally powered by DC, which is less efficient. Summary of the invention

The invention provides a power supply modulator for solving the problem of low efficiency of the conventional DC power supply mode of the linear power supply regulator in the prior art.

Specifically, the present invention provides a power supply modulator, including: a switching power supply regulator and a linear power supply regulator connected in parallel; the switching power supply regulator and a linear power regulator adjust an input reference information to be tracked After processing, the output voltage of the switched mode power regulator and the output voltage of the linear power regulator are combined into a total output voltage of the power supply modulator, characterized in that the linear power regulator is powered by a non-DC power supply.

The manner in which the linear power regulator is powered by a non-DC power supply includes: supplying power to the linear power regulator by the switch power regulator; or, the total output voltage of the power modulator is The linear power regulator is powered; or, the power modulator is provided with a second switching power regulator, and the second switching power regulator supplies power to the linear power regulator; the second switching power supply adjusts The input signal of the device is the reference signal to be tracked.

Preferably, the power supply modulator of the present invention further has the following features:

The power modulation circuit further includes: a first bias power supply and/or a second bias power supply; wherein the first bias power supply is configured to bias a supply voltage to be input to the linear power regulator After processing, output to the positive terminal of the linear power regulator;

The second bias power supply is configured to perform a bias voltage processing on a supply voltage to be input to the linear power regulator, and output the voltage to a negative terminal of the linear power regulator.

The power modulator further includes:

An impedance matching circuit is configured to filter and output the output voltages of the switching power supply regulator and the linear power regulator.

The power modulator further includes: a delay circuit for compensating the switch power regulator Circuit delay between the linear power regulator and the linear power regulator.

In the power modulator, an output voltage of the linear power regulator forms a closed loop circuit as a feedback signal of the linear power regulator.

Alternatively, in the power modulator, the total output voltage of the power modulator forms a closed loop circuit as a feedback signal of the line regulator.

In the power supply modulator of the present invention, the impedance matching circuit includes a low pass filter and a high pass filter;

The low pass filter is connected to the switch power regulator for low pass filtering processing on an output voltage of the switch power regulator;

The high pass filter is coupled to the linear power regulator for high pass filtering of an output voltage of the linear power regulator.

The beneficial effects of the present invention are as follows:

The power supply modulator provided by the invention uses a non-DC power supply mode to change the way that the conventional DC power supply supplies power to the linear power regulator, thereby overcoming the problem of low efficiency; When the switching power supply regulator is powered, the switching power supply regulator can be used to track the characteristics of the reference envelope signal, and the output is simultaneously supplied to the linear power regulator to realize the linear power regulator when the output voltage is low. The supply voltage modulation function with lower supply voltage can improve the efficiency of the linear power regulator while maximizing the tracking accuracy and bandwidth of the power modulator output without increasing the cost and circuit complexity. The efficiency of the system. DRAWINGS

1 is a schematic structural view of a switching power supply regulator in the prior art;

2 is a schematic view showing a combination of a switching power supply regulator and a linear power regulator in the prior art;

3 is a schematic structural diagram of a power modulator according to the present invention; 4 is a schematic structural diagram of still another power supply modulator provided by the present invention;

FIG. 5 is a schematic structural diagram of still another power supply modulator provided by the present invention; FIG.

6 is a schematic diagram of a voltage waveform of a power supply modulator according to Embodiment 1 of the present invention; FIG. 7 is a schematic structural diagram of a power supply modulator according to Embodiment 2 of the present invention; FIG. 9 is a schematic structural diagram of a power supply modulator according to Embodiment 3 of the present invention; FIG. 10 is a schematic diagram of voltage waveforms of the power supply modulator according to Embodiment 3 of the present invention; FIG. 12 is a schematic structural diagram of a power supply modulator according to Embodiment 5 of the present invention; FIG. 13 is a schematic structural diagram of a power supply modulator according to Embodiment 6 of the present invention; FIG. 14 is a schematic structural view of an impedance matching circuit according to the present invention. detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In order to solve the problem that the linear power supply mode of the prior art is low in efficiency by the conventional DC power supply mode, the present invention provides a power supply modulator which can ensure the tracking precision and bandwidth of the power modulator output at the maximum extent. At the same time, improve the efficiency of the system; and the power modulator can be used for envelope tracking RF signal power amplifier and other requirements for tracking modulation of the supply voltage, wherein the power supply for the envelope tracking RF signal power amplifier can improve the RF signal power The efficiency of the amplifier; in addition, the power modulator of the present invention can also be used independently as a power amplifier such as an audio signal amplifier or the like.

Specifically, the present invention provides a power supply modulator, including: a switching power supply connected in parallel a regulator and a linear power regulator; the switching power regulator and the linear power regulator adjust the input reference information to be tracked, and the output voltage of the switching power regulator and the output voltage of the linear power regulator are combined The total output voltage of the power supply modulator is characterized in that the linear power regulator is powered by a non-DC power supply.

3, FIG. 4, and FIG. 5 are respectively schematic structural diagrams of three power modulators according to an embodiment of the present invention. Referring to FIG. 3, FIG. 4, and FIG. 5, the linear power conditioner is powered by a non-DC power supply. :

As shown in FIG. 3, the linear power regulator is powered by the switching power regulator; or, as shown in FIG. 4, the linear power regulator is powered by the total output voltage of the power modulator; or, as shown in FIG. Providing a second switching power regulator in the power modulator, wherein the linear power regulator is powered by the second switching power regulator; the input signal of the second switching power regulator is the reference signal to be tracked .

Based on the above power supply mode, the power supply modulator provided by the present invention further includes at least one of the following technical features, or a combination of the following technical features, as follows:

The power modulator further includes:

a first bias power supply for performing a bias voltage processing on the power supply voltage to be input to the linear power regulator, and outputting the power supply voltage to the positive terminal of the linear power regulator;

a second bias power supply, configured to perform a bias voltage processing on the power supply voltage to be input to the linear power regulator, and output the voltage to the negative terminal of the linear power regulator;

An impedance matching circuit, configured to filter and output an output voltage of the switching power supply regulator and the linear power regulator;

a delay circuit for compensating for a circuit delay between the switched mode power regulator and the linear power regulator;

In the power modulator, an output voltage of the linear power regulator is used as a feedback signal of the linear power regulator to form a closed loop circuit, or, in the power modulator, the power source The total output voltage of the modulator forms a closed loop circuit as a feedback signal of the linear power regulator; the power modulator provided by the present invention uses a non-DC power supply to change the conventional DC power supply to a linear power regulator. The power supply method overcomes the original inefficiency problem; and when the switch power supply regulator is used for power supply, the switching power supply regulator can be used to track the characteristics of the reference envelope signal and output it. At the same time, the linear power regulator is powered, which realizes the supply voltage modulation function of the linear power regulator with lower supply voltage when the output voltage is lower, thereby improving the linear power regulator without increasing the cost and circuit complexity. s efficiency.

In the following, several preferred embodiments of the present invention will be described with reference to FIG. 6 to FIG. 14 and the technical details of the present invention will be further described in conjunction with the description of the specific embodiments, so that the description of the present invention can be better illustrated. The specific implementation process of the method. Of course, the following embodiments are only a few preferred embodiments.

The present embodiment provides a power supply modulator, the structure of which is shown in FIG. 3. The power supply modulator specifically includes: a switching power supply regulator 301 and a linear power regulator 302;

The switched mode power regulator 301 is coupled in parallel with the linear power regulator 302, and the switched mode power regulator 301 supplies power to the linear power regulator 302; the switched mode power regulator 301 is powered by a DC power source.

The working principle of the power modulator is: after the reference signal 305 to be tracked is input to the switching power supply regulator 301 and the linear power regulator 302, the switching power supply adjustment and the linear power supply adjustment are respectively performed to obtain output voltages 303 and 304, and then Output voltages 303 and 304 are combined into a total output voltage 306 of the power supply modulator.

The power supply modulator provided in this embodiment supplies power to the linear power regulator 302 through the switching power conditioner 301, which overcomes the direct use of the linear power regulator 302 existing in the prior art. The problem of low efficiency of traditional DC power supply. The power supply modulator according to the embodiment uses the switching power supply regulator to track the characteristics of the reference envelope signal, and simultaneously outputs the output to the linear power regulator, thereby realizing the linear power regulator to supply power when the output voltage is low. The supply voltage modulation function, which also has a lower voltage, improves the efficiency of the linear power regulator without increasing the cost and circuit complexity, thereby further improving the efficiency of the system. The output voltage waveform obtained by the power supply modulator of the embodiment is as shown in FIG. 6, wherein 401 is a switching power supply regulator 301 output voltage waveform, and 402 is a linear power regulator 302 output voltage waveform. Embodiment 2

FIG. 7 is a schematic structural diagram of a power modulator according to Embodiment 2 of the present invention. As shown in FIG. 7, the power modulator includes: a switching power regulator 301 and a linear power regulator 302; wherein, the switch The power regulator 301 is connected in parallel with the linear power regulator 302, and the switching power regulator 301 supplies power to the linear power regulator 302; the switched power regulator 301 is powered by a DC power supply;

Further, the power modulator further includes: a first bias power supply 501, an impedance matching circuit 502, and a delay circuit 503; wherein:

The first bias power supply 501 is configured to output the bias voltage of the switching power supply regulator 301 to the power supply voltage of the linear power regulator 302 for output to the linear power regulator 302, thereby more effectively ensuring the linear power regulator 302. The supply voltage is higher than the output voltage;

The impedance matching circuit 502 is configured to filter and output the output voltage 303 of the switching power supply regulator 301 and the output voltage 304 of the linear power regulator;

The delay circuit 503 is configured to delay the reference signal to be tracked of the input linear power regulator 302 to compensate for different circuit delays of the switched power regulator 301 and the linear power regulator 302.

Preferably, the output voltage 304 of the linear power regulator 302 can also be used as a feedback signal to form a closed loop circuit, thereby further improving tracking accuracy. The power supply voltage waveform generated by the power supply modulator of this embodiment is as shown in FIG. 8, wherein 601 is the voltage waveform of the output voltage 303 of the switching power supply regulator 301 after the first bias power supply 501, and 602 is the linear power supply adjustment. The output voltage 304 of the device 302 is a waveform. It can be seen from the figure that the power supply modulator described in this embodiment is more implementable. Embodiment 3

FIG. 9 is a schematic structural diagram of a power modulator according to Embodiment 3 of the present invention. As shown in FIG. 9, the power modulator includes:

a switching power supply regulator 301, a linear power regulator 302, a first bias power supply 501, an impedance matching circuit 502, and a delay circuit 503;

Wherein, the switching power supply regulator 301 is connected in parallel with the linear power regulator 302, and the switching power regulator 301 supplies power to the linear power regulator 302; the switching power regulator 301 is powered by a DC power supply;

The first bias power supply 501 is configured to output the switching power supply regulator 301 to the supply voltage of the linear power regulator 302 for bias voltage processing and output to the linear power regulator 302;

Further, the switching power supply regulator 301 of the embodiment further supplies power to the negative terminal of the linear power regulator 302;

Preferably, the power supply modulator of the embodiment further includes a second bias power supply 702, configured to perform a bias voltage processing on the power supply voltage outputted by the switching power supply regulator 301, and output the output to the linear The negative terminal of the power conditioner 302.

The power supply voltage waveform generated by the power supply modulator provided in this embodiment is as shown in FIG. 10, wherein 801 is the output voltage 303 of the switching power supply regulator 301 after the first bias power supply 501 voltage waveform, 802 is the output voltage 304 waveform of the linear power regulator 302, 803 is the switching power supply regulator 301 output voltage 303 through the second The voltage waveform after the power supply 702 is biased. The voltage tracking of the positive and negative terminals can be realized by the power modulator of the embodiment, so that the loss of the linear power regulator 302 is smaller. Embodiment 4

FIG. 11 is a schematic structural diagram of a power modulator according to Embodiment 4 of the present invention. As shown in FIG. 11, the power modulator specifically includes:

a switching power supply regulator 301 and a linear power regulator 302; wherein the switching power supply regulator 301 is connected in parallel with the linear power regulator 302, and the switching power supply regulator 301 supplies power to the linear power regulator 302; The power conditioner 301 is powered by a DC power source;

The power modulator further includes: a first bias power supply 501, an impedance matching circuit 502, and a delay circuit 503; wherein:

The bias power supply 501, the supply voltage for outputting the switching power supply regulator 301 to the linear power regulator 302 is bias voltage processed and output to the linear power regulator 302;

Further, the power modulator of the present embodiment also forms a closed loop circuit with the total output voltage 306 of the power modulator as a feedback signal of the linear power regulator 302.

This embodiment can not only ensure that the power supply voltage of the linear power regulator 302 is higher than the output voltage, but also further improve the tracking accuracy. Embodiment 5

FIG. 12 is a schematic structural diagram of a power modulator according to Embodiment 5 of the present invention. As shown in FIG. 12, the power modulator includes: a switching power regulator 301, a linear power regulator 302, and a first bias power supply 501. The impedance matching circuit 502 and the delay circuit 503; wherein the switching power supply regulator 301 is connected in parallel with the linear power regulator 302, and the output voltage 303 of the switching power supply regulator 301 and the output voltage 304 of the linear power regulator 302 pass through The impedance matching circuit 502 processes the total output voltage 306;

In this embodiment, the power supply mode of the linear power regulator 302 is powered by the total output voltage 306 of the voltage modulator;

The first bias power supply 501 is configured to perform voltage bias processing on the supply voltage of the input linear power regulator 302, and output the processed supply voltage to the linear power regulator 302.

Of course, this embodiment can further improve the tracking accuracy and the like by increasing the feedback loop. Embodiment 6

13 is a schematic structural diagram of a power modulator according to Embodiment 6 of the present invention. As shown in FIG. 13, the power modulator includes: a switch power conditioner 301, a linear power regulator 302, an impedance matching circuit 502, and a delay. Time circuit 503 and second switching power supply regulator 308;

The switching power supply regulator 301 is connected in parallel with the linear power regulator 302, the output voltage 303 of the switching power supply regulator 301 and the output voltage 304 of the linear power regulator 302 are processed by the impedance matching circuit 502 to output a total voltage 306;

In this embodiment, the second switching power regulator 308 is used to supply the linear power regulator 302. Preferably, the output voltage of the second switching power regulator 307 can be processed by the bias power supply to supply the linear power regulator 302.

Of course, in this embodiment, the tracking accuracy and the like can be further improved by adding a feedback loop. It should be noted that, in the foregoing Embodiments 1 to 6, the output voltage 303 of the switching power supply regulator 301 can roughly track the reference signal 305, and the structure thereof may be, but not limited to, a high bandwidth multi-level voltage source, such as a picture. Class-G shown in 1;

The output voltage 304 of the linear power regulator 302 can accurately track the input reference signal 305, which may be, but is not limited to, conventional ones such as Class-A, push-pull push-pull structures.

Further, in the above embodiment, the structure of the impedance matching circuit 502 can be a combination of a low pass filter and a high pass filter as shown in FIG. The output voltage 303 of the switched mode power regulator 301 is coupled to a low pass filter, the output voltage 304 of the linear power regulator 302 is coupled to a high pass filter, and the output combination of the high pass filter and the low pass filter form a total output voltage 306 of the power supply modulator. . Specifically, the low pass filter and the high pass filter may be composed of passive component inductance, resistance, capacitance, and the like.

The power supply modulator provided by the invention uses a non-DC power supply mode to change the way that the conventional DC power supply supplies power to the linear power regulator, thereby overcoming the problem of low efficiency; When the switching power supply regulator is powered, the switching power supply regulator can be used to track the characteristics of the reference envelope signal, and the output is simultaneously supplied to the linear power regulator to realize the linear power regulator when the output voltage is low. The supply voltage modulation function, which also has a lower supply voltage, improves the efficiency of the linear power regulator without increasing cost and circuit complexity. The spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the invention

Claims

Claim

1. A power supply modulator, comprising: a switching power supply regulator and a linear power supply regulator connected in parallel; the switching power supply regulator and the linear power regulator adjust and process the input reference information to be tracked, and switch The output voltage of the power conditioner and the output voltage of the linear power regulator are combined into a total output voltage of the power modulator, characterized in that the linear power regulator is powered by a non-DC power source.

2. The power supply modulator of claim 1 wherein said linear power regulator is powered by a non-DC power supply:

Supplying the linear power regulator by the switch power regulator; or, powering the linear power regulator by a total output voltage of the power modulator; or, the power modulator is provided with a second switch The power regulator is configured to supply power to the linear power regulator by the second switching power regulator; the input signal of the second switching power regulator is the reference signal to be tracked.

3. The power supply modulator of claim 2, wherein the power supply modulator further comprises: a first bias power supply and/or a second bias power supply;

The first bias power supply is configured to perform a bias voltage processing on a supply voltage to be input to the linear power regulator, and output the same to a positive terminal of the linear power regulator;

4. The power supply modulator of claim 2, wherein the power supply modulator further comprises:

The power supply modulator of claim 3, wherein the power supply modulator further comprises: An impedance matching circuit is configured to filter and output the output voltage of the switching power supply regulator and the linear power regulator.

The power supply modulator according to any one of claims 2 to 5, wherein the power supply modulator further comprises: a delay circuit for compensating between the switching power supply regulator and the linear power regulator Circuit delay.

The power supply modulator according to any one of claims 2 to 5, wherein, in the power supply modulator, an output voltage of the linear power regulator is used as a feedback signal of the linear power regulator to form a closed loop Circuit.

The power supply modulator according to claim 6, wherein in the power supply modulator, an output voltage of the linear power regulator is used as a feedback signal of the linear power regulator to form a closed loop circuit.

The power supply modulator according to any one of claims 2 to 5, wherein, in the power supply modulator, a total output voltage of the power supply modulator forms a closed loop as a feedback signal of the linear power regulator Circuit.

10. The power supply modulator of claim 6, wherein in the power supply modulator, a total output voltage of the power supply modulator forms a closed loop circuit as a feedback signal of the linear power regulator.

The power supply modulator according to claim 4 or 5, wherein the impedance matching circuit comprises a low pass filter and a high pass filter;