KR100949821B1 - Linearization apparatus for power amplifier of slave path in multi-path - Google Patents

Abstract

An object of the present invention is to provide a linearization device for a power amplifier of a slave path that can reduce signal loss and simplify a circuit required for linearization of a power amplifier to which a multiple input multiple output method is applied.

To this end, in the present invention, in linearizing the output signals of the power amplifiers respectively installed in the master path and the slave path according to the multiple input multiple output method, a divider for distributing the power amplifier output signals of the master path in which the linearization device is installed; A predistorter for receiving a signal from the splitter and predistorting a source frequency signal of a slave path, the predistorter having a coupler for coupling a signal of a slave path; A power combiner configured to combine the signals inputted through the splitter and the coupler to output an interphase intermodulation signal; Disclosed is a power amplifier linearizer of a slave path among multiple paths including a distortion signal combiner for combining an interphase intermodulation signal output from the power combiner and a signal input to a power amplifier of a slave path.

WiBro, Multiple Input Multiple Output, Linearization, Power Amplifier.

Description

Linearization apparatus for power amplifier of slave path in multi-path}

The present invention relates to a linearization device for a power amplifier, and more particularly, to reduce the signal loss and simplify the circuit structure required for the linearization of a power amplifier to which a multiple input multiple output method is applied. The present invention relates to a power amplifier linearization device.

In recent years, the wireless communication field has been concentrated on personalization and multimedia, and ultimately, technology development has been made toward the next generation communication technology of 3.5G and 4G beyond IMT-2000. In order to be widely used for wireless communication, stable operating system, high performance communication base station system, and miniaturization, light weight, and low price should be achieved, and research and source technology of RF core components such as power amplifier are essential for enhancing stability and competitiveness.

What is important in the digital system is that data must be transmitted only by maintaining the linearity of the signal with linear modulation. The high power amplifier is responsible for maintaining the linearity of these signals and transmitting them. In general, it is common to have nonlinear circuit characteristics by the nonlinear characteristics of active elements used in RF and microwave circuits.

In particular, the power amplifier operates the transistor, which is the main active element, in a saturation region with strong nonlinear characteristics to extract the maximum power, and intermodulation signals are generated due to the nonlinear characteristics near the saturation region.

The intermodulation signals as described above act as interference or noise, causing deterioration of transmission quality. Therefore, when used with a power amplifier by incorporating a linearization technology that compensates for the non-linear characteristics of the power amplifier, it is possible to obtain a desired output power while significantly reducing intermodulation signals generated during co-amplification of multiple carriers even in a saturated region.

Such linearization methods include a back-off method, a negative feedback method, a predistortion method, and a feedforward method.

In the linearization method using predistortion, the predistortion circuit having inverse distortion characteristics is installed in the input stage of the power amplifier in consideration of the distortion component generated when the basic input signal is amplified by the main amplifier. This is a method of canceling the distortion component.

In addition, the linearization method through the feedforward extracts some of the output signal and then removes the coupling signal from the original input signal, thereby leaving only the inverse intermodulation (IMD) signal, and the negative intermodulation signal is an error amplifier ( After amplification through the error amplifier, the main amplifier's output terminal is recombined with the main signal to cancel the distortion component of the main amplifier.

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The conventional power amplifier employing the predistortion or feedforward linearization device compensates for the nonlinear characteristics, thereby ensuring linearity, and is used in a single input single output mobile communication system. In case of applying to 3.5G mobile communication system such as WiBro (Wireless Broadband Internet), there are many problems in terms of signal loss and production cost due to Multiple Input Multiple Output (MIMO). This occurred.

In more detail, when the above-described conventional power amplifier is installed in a multi-input multiple output type repeater, the power amplifier should be installed in both the multipath consisting of the master path and the slave path. In this case, since the power amplifier adopts all the linearizers, the circuit structure becomes complicated and the production cost of the power amplifier is greatly increased.

In addition, since a delay element such as a delay is used as the linearizer of the power amplifier, a loss of an output signal is inevitably generated, which causes a problem of lowering the overall performance of the device employing the power amplifier.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to simplify the linearization apparatus of a power amplifier installed in a slave path of a multipath. To provide a linearizer.

Another object of the present invention is to provide a power amplifier linearization apparatus of a slave path among multiple paths that can reduce the loss of an output signal during the linearization of the power amplifier.

In order to achieve the above object, the present invention is to linearize the output signal of the power amplifier installed in each of the master path and the slave path according to the multiple input multiple output method, the power amplifier output signal of the master path is installed linearizer And a predistorter for receiving a signal from the divider and predistorting the source frequency signal of the slave path, wherein the predistorter comprises: a coupler for coupling a signal of the slave path; A power combiner configured to combine the signals inputted through the splitter and the coupler to output an interphase intermodulation signal; Provided is a power amplifier linearization device of a slave path among multiple paths including a distortion signal combiner for combining an interphase intermodulation signal output from the power combiner and a signal input to a power amplifier of a slave path.

The present invention compensates the nonlinear characteristics of the output signal outputted from the power amplifier of the slave path through the divider of the master path and the predistorter of the slave path, thereby simplifying the circuit structure, reducing the volume, and greatly reducing the cost of the linear power amplifier. It has a very useful effect.

In addition, in the present invention, since a delay element such as a delay is not used in the linearization process, the loss of the output signal due to signal delay is minimized, thereby improving the performance of equipment such as a repeater employing a linear power amplifier.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment>

FIG. 1 is a circuit diagram schematically illustrating a power amplifier linearization device of the present invention in which a master path and a slave path are configured one by one. As shown, the present invention is composed of a divider 100 and a predistorter 200.

First, the divider 100 distributes a signal coupled from an output signal of the power amplifier PA ₀ installed in the master path TX _{0. In the} present invention, as an example, the linearity of the power amplifier PA ₀ is secured. The above-described distributor 100 was installed between the coupler (Coupler, 12) and the power combiner (Power combiner, 13) installed for.

Accordingly, the divider 100 transmits the output signal of the power amplifier PA ₀ input from the coupler 12, that is, the output signal including the intermodulation component, to the power combiner 13 and the predistorter 200. Will output

Here, the feed forward linearization device 10 including the couplers 11 and 12, the power combiner 13, the error amplifier (Error Amplifier / 14), and the delays 15 and 16 is installed in the master path TX ₀ . By compensating for the nonlinear characteristics of the power amplifier PA ₀ installed in the master path TX ₀ . However, in addition to the feedforward linearization device 10, various linearization devices such as a back-off method, a negative feedback method, and a predistortion method may be applied.

The predistorter 200 receives a signal from the divider 100 and predistorts the signal input to the power amplifier PA ₁ of the slave path TX _{1. In the} present invention, for example, the coupler 210, The power combiner 220 and the distortion signal combiner 230 are configured.

Here, the coupler 210 couples the source frequency signal of the slave path TX ₁ , and the power combiner 220 couples the respective signals input from the divider 100 and the coupler 210. The intermodulation signal of the inverse phase is extracted, and the distortion signal combiner 230 combines the inverse phase intermodulation signal output from the power combiner 220 and the source frequency signal of the slave path TX ₁ . It will play a role.

Therefore, in addition to the fundamental frequency, the power amplifier PA ₁ installed in the slave path TX ₁ receives a predistorted signal from the predistorter 200, that is, an interphase intermodulation signal, so that the slave path TX ₁₎ it is possible to linearize the output signal of the power amplifier (PA ₁₎ is installed on.

As described above, the present invention provides a slave path through a divider 100 for distributing the output signal of the power amplifier PA ₀ of the master path TX ₀ and a predistorter 200 installed in the slave path TX ₁ . compensating for the nonlinear characteristic of the power amplifier (PA ₁₎ provided in the TX ₁₎ Since the linearization of a power amplifier (PA ₁₎ provided in the slave path (TX ₁₎ it can be implemented very simply.

In particular, the predistorter 200 of the present invention simply consists of a coupler 210, a power combiner 220 and a distortion signal combiner 230, so that the circuit configuration is very simple, thereby dramatically reducing the cost of the linear power amplifier. In addition to reducing the volume, the volume can be greatly reduced.

In addition, in the predistorter 200 of the present invention, since a delay element such as delays 15 and 16 is not used in the slave path TX ₁ , the loss of the output signal due to signal delay can be minimized. The performance of equipment such as a repeater employing a power amplifier can be improved.

Second Embodiment

FIG. 2 is a circuit diagram schematically illustrating another example of a multipath consisting of one master path and a plurality of slave paths and a linearization device of a power amplifier according to another embodiment of the present invention.

As shown, each pre-distorter 200 is installed in each slave path TX ₁ to TX _n , and the predistorter 200 transposes source frequency signals of the slave paths TX ₁ to TX _n . The distortion compensates for the nonlinear characteristics of the power amplifiers PA ₁ to PA _n installed in the slave paths TX ₁ to TX _n .

Thus the present invention shown in Figure 2 is the master path (TX ₀₎ only in the feed forward or predistortion, and linearization device 10 is installed, such as, the master path remaining multipath that is, a plurality of the slave path, except for (TX ₀₎ ( TX ₁ ~ TX _n ) is because the predistorter 200 is installed respectively, greatly reducing the circuit structure and volume for the linearization as a whole, and dramatically reduces the cost of the linear power amplifier.

Third Embodiment

FIG. 3 shows another embodiment of the present invention, and is a circuit diagram schematically illustrating an example of a multipath including a plurality of master paths and slave paths and a linearization device of a power amplifier.

As shown, all the distributors 100 are installed in each of the master paths TX ₀ and TX2 ₂ in which the linearizer 10 is installed, and the predistorter 200 is installed in each of the slave paths TX ₁ and TX ₃ . Are all installed.

Therefore, each predistorter 200 receives a signal from each of the distributors 100 installed in the master paths TX ₀ and TX2 ₂ and presistors the source frequency signals of the slave paths TX ₁ and TX ₃ . The nonlinear characteristics of the power amplifiers PA _{1 and} PA ₃ installed in the paths TX ₁ and TX ₃ are compensated for.

Accordingly, in the present invention shown in FIG. 3, the linearizer 10 such as feedforward or predistortion is installed only in the master paths TX ₀ and TX ₂ , as in the first embodiment, and the remaining multipaths, that is, multiple slave paths. Since the predistorters 200 are respectively installed in the TX ₁ and TX ₃ , the circuit structure and volume for linearization are greatly reduced, and the cost of the linear power amplifier is greatly reduced.

As described above, the embodiments of the present invention are merely illustrative of preferred examples, and the scope of application of the present invention is not limited thereto, and may be appropriately changed within the scope of the same idea.

1 is a circuit diagram schematically showing a linearization device for a power amplifier of the present invention.

2 is a circuit diagram schematically showing another embodiment of the linearizer for power amplifier of the present invention.

Figure 3 is a circuit diagram schematically showing another embodiment of the linearizer for power amplifier of the present invention.

<Description of Symbols for Main Parts of Drawings>

10: linearization device 100: distributor

200: predistorter 210: coupler

220: power combiner 230: distortion signal combiner

TX ₀ , TX ₁ , TX ₂ , TX ₃ , TX _n : Path PA ₀ , PA ₁ , PA ₂ , PA ₃ , PA _n : Power Amplifier

Claims (6)

In the linearization of the output signal of the power amplifier installed in each of the master path and the slave path according to the multiple input multiple output method, a divider for distributing the power amplifier output signal of the master path, the linearization device is installed, and the signal from the divider A predistorter for predistorting the source frequency signal of the slave path, the predistorter comprising: a coupler for coupling a signal of the slave path; A power combiner configured to combine the signals inputted through the splitter and the coupler to output an interphase intermodulation signal; And a distortion signal combiner configured to combine an interphase intermodulation signal output from the power combiner and a signal input to a power amplifier of a slave path. delete delete The apparatus of claim 1, wherein the master path is composed of one path, and the slave path is composed of a plurality of paths. The apparatus of claim 1, wherein the master path and the slave path each comprise a plurality of paths. delete

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