KR20070024088A - Power analyzing system of output unit for communication module and method thereof - Google Patents

Abstract

A system and a method for analyzing power of the output stage of a communication module are provided to maximize the transmitting/receiving distance of RF communication devices by deducing the maximum output power value of a power amplifier in accordance with ACPR(Adjacent Channel Power Ratio) and EVM(Error Vector Magnitude) standards and efficiently executing power matching of the power amplifier. A system for analyzing power of the output stage of a communication module consists of a level selection part(110), a power supply part(120), an ACPR value measurement part(130), an ACPR value selection part(140), an EVM value selection part(150), and a value extraction part(160). A user inputs a plurality of PCVs(Power Control Values) for a power amplifier(10) to the level selection part(110). The power supply part(120) supplies power equivalent to each PCV to input stage of the power amplifier(10). The ACPR value measurement part(130) measures ACPR values of the output stage of the power amplifier(10). The ACPR value selection part(140) compares the ACPR values transmitted from the ACPR value measurement part(130) with ACPR spectrum standards and selects the nearest ACPR value to the ACPR spectrum standards. The EVM value selection part(150) creates a PCV list equivalent to the selected ACPR value and obtains a PCV close to the threshold of EVM standards from the PCV list. The value extraction part(160) extracts an output power value corresponding to the obtained PCV.

Description

Power analyzing system and output analysis method of output terminal for communication module

1 is a schematic block diagram of a typical power amplifier and adjacent electronic components.

2 is a block diagram schematically illustrating components of a power analysis system of an output stage for a communication module according to an embodiment of the present invention;

3 is a graph showing the correlation between the output power value and the PCV of the power amplifier according to an embodiment of the present invention.

4 is a graph illustrating a spectral mask according to an ACPR standard included in an ACPR value selection unit according to an embodiment of the present invention.

5 is a polar coordinate diagram of an I / Q signal format in which EVM changes as power increases on a power analysis system of an output terminal for a communication module according to an embodiment of the present invention.

6 is a polar diagram illustrating an example of the concept of the EVM generated as the power is increased on the power analysis system of the output terminal for the communication module according to the embodiment of the present invention.

7 is a table showing the EVM standard used on the power analysis system of the output terminal for a communication module according to an embodiment of the present invention.

FIG. 8 is a graph illustrating comparison of numerical values used by a power analysis system of an output terminal for a communication module according to an embodiment of the present invention to find an input level power value having a maximum value while simultaneously satisfying an ACPR standard and an EVM standard.

9 is a flowchart illustrating a power analysis method of an output terminal for a communication module according to an embodiment of the present invention.

<Explanation of symbols for main parts of drawing>

100: power analysis system of output terminal for communication module

10: power amplifier 110: level selector

120: power supply unit 130: ACPR numerical measurement unit

140: ACPR value selection unit 150: EVM value selection unit

160: numerical extracting unit 170: control unit

The present invention relates to a power analysis system and a power analysis method of the output terminal for the communication module.

Currently, mobile communication terminals such as mobile phones, smart phones, personal digital assistants (PDAs), and radio frequency identification (RFID) devices are widely used, and various electronic devices are embedded and these electronic devices are mounted on a printed circuit board (PCB). It is common to form an integrated module (communication module).

In general, two communication amplifiers are used in the communication module, one of which is a power amplifier (PA) used at an output stage and the other is a low noise amplifier (LNA) used at a receiving stage.

On the other hand, Wireless Local Area Network (WLAN), which has been the subject of interest in recent years, enables network communication while moving freely in a home, office, or public place without using a wired cable. The range of applications is expected to increase in the future due to the advantages of high data rate, two-way communication, simple installation environment, and the possibility of connecting a large number of devices.

Such a WLAN is largely composed of a wireless access device and a mobile communication terminal interworking with a wired network, and the wireless access device may be an access point (AP). AP is a wireless LAN device that can form a network of several Mbps to several tens of Mbps using ISM (Indutrial, Scientific and Medical) band of 2.4GHz frequency band without license, and a mobile communication terminal equipped with a wireless LAN card. Connect with and provide communication channel.

The AP follows the high-speed 802.11 standard of DSSS (Direct Sequence Spread Spectrum). The reason is that the existing AP supporting 2Mbps speed and the latest AP supporting 11Mbps speed coexist and move to high speed 11Mbps environment easily. This is because there is compatibility between different products.

As described above, the WLAN equipment includes a communication module to perform network communication, and a power amplifier is used at an output terminal of the communication module.

In order to maximize the transmission / reception distance of the communication module provided in the WLAN equipment, the transmission power should also be kept to the maximum, and the transmission power has a limitation in amplifying.

This is in accordance with the Adjacent Channel Power Ratio (ACPR) regulations defined in the IEEE 802.11 standard, which defines the linear characteristics of the power amplifier.

That is, the channel signal is basically amplified within a predetermined frequency bandwidth, but intermodulation occurs in the bandwidth of the channel signal where several frequencies are concentrated, and this phenomenon invades adjacent channel frequencies to form unnecessary energy.

Thus, the linearity of the power amplifier is incomplete.

Due to the above-described reasons, the power amplifier has a limitation in maximizing its output, and when the power amplifier output is increased, the ACPR value is also increased, so that the aspect of the ACPR must be considered to realize the maximum output of the power amplifier.

The method of setting the output of the conventional power amplifier to the maximum is as follows.

1 is a block diagram schematically illustrating a general power amplifier 10 and adjacent electronic devices 20 and 30.

In the conventional setting method using the matching elements 20 and 30, a predetermined output value is set through experiments without obtaining the maximum output value of the power amplifier in a range that does not affect the adjacent channel. This is a method of setting this using a matching element such as the capacitor 20 and the coil 30 shown in FIG. 1.

Therefore, in order to match the input terminal impedance (z1) and the output terminal impedance (z2) of the power amplifier, it is necessary to perform the task of matching the elements 20, 30 separately, it takes a lot of time, Since it is a mismatching method in which the output power value and the ACPR value are not considered together, it is difficult to expect high efficiency of the power amplifier 10.

In addition, there is a conventional method of trimming the output power value and the ACPR value of the power amplifier, but this is a method of trimming the ACPR value after setting the output power value, the setting of the output power value, ACPR value Since the trimming process must be repeated, it is troublesome and time-consuming.

Therefore, the present invention excludes a method of matching a conventional electronic device or a method of repeatedly comparing the output power value and the ACPR value of the power amplifier by repeating the trimming operation, and does not violate the ACPR and EVM standards through a minimum trimming process. It is an object of the present invention to provide a power analysis system of an output stage for a communication module that can analyze the maximum value of the output power in an unranged range and efficiently set the power of the power amplifier.

In addition, the present invention first considers the ACPR and EVM standards by improving the inefficiency of the method of determining whether the set output value conforms to the ACPR and EVM standards after setting the output value in order to derive the maximum output power value. Another object of the present invention is to provide a power analysis method of an output terminal for a communication module that can set a maximum power by comparing output power values uniformly.

In order to achieve the above object, the power analysis method of the output terminal for a communication module according to the present invention comprises the steps of setting the ACPR (Adjacent Channel Power Ratio) spectrum standard; Setting a plurality of input level values of the power amplifier; Measuring an ACPR value of the power amplifier output stage power as the power having the input level value is input to the power amplifier; Retrieving the input level value corresponding to the case where the ACPR value approaches the threshold of the ACPR spectrum standard; Generating an input level value list having the retrieved input level value as a maximum value, and retrieving an input level value corresponding to an error vector magnitude (EVM) standard by applying the input level value on the list; ; And extracting an output power value of the power amplifier corresponding to the found input level value.

The extracting of the output power value of the power amplifier of the power analysis method of the output terminal for the communication module according to the present invention may include repeating the step of setting the input level value or searching for the input level value according to the EVM standard. After the output power value is characterized in that it is extracted.

In addition, the step of extracting the output power value of the power amplifier of the power analysis method of the output terminal for the communication module according to the present invention, the impedance between the input and output terminals of the power amplifier based on the retrieved input level value and the extracted output power value It is characterized in that it further comprises the step of matching.

In addition, the power analysis system of the output terminal for the communication module according to the present invention includes a level selection unit for setting a plurality of input level values of the power amplifier; A power applying unit configured to apply power corresponding to the transmitted input level value to an input of the power amplifier; An ACPR value measuring unit measuring an ACPR value of the output stage of the power amplifier to which the input level value is applied; An ACPR value selection unit having an ACPR spectrum standard and selecting an ACPR value closest to the ACPR spectrum standard by comparing the ACPR value transmitted from the ACPR numerical measurement unit with the ACPR spectrum standard; An EVM value selection unit for generating an input level value list corresponding to the selected ACPR value and searching for an input level value approaching a threshold of an EVM standard on the list; And a numerical extractor extracting an output power value of the power amplifier corresponding to the input level value transmitted from the EVM value selector.

In addition, the power analysis system of the output terminal for the communication module according to the present invention further comprises a control unit for proceeding the operation process of the level selection unit, power application unit, ACPR value measurement unit, ACPR value selection unit, EVM value selection unit and numerical extraction unit. And the control unit repeatedly functions the level selection unit, the power applying unit, the ACPR value measuring unit, the EVM value selecting unit, and the ACPR value selecting unit, and the numerical extracting unit selects the input level value finally selected through the repeating function. Is received from the EVM value selection unit.

In addition, the input level value list of the power analysis system of the output terminal for the communication module according to the present invention is characterized in that it is formed to the maximum value of the input level value corresponding to the selected ACPR value.

Hereinafter, a power analysis system and a power analysis method of an output terminal for a communication module according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram schematically illustrating components of a power analysis system 100 of an output terminal for a communication module according to an embodiment of the present invention.

2, the power analysis system 100 of the output terminal for the communication module according to an embodiment of the present invention is a level selector 110, a power applying unit 120, ACPR value measuring unit 130, ACPR value selection unit 140, the EVM value selection unit 150, the numerical extractor 160, and the controller 170.

First, the level selector 110 receives a plurality of input level values of the power amplifier 10 from a user, wherein the input level values are numerical values for controlling output power of the power amplifier 10 (PCV; power). control value, hereinafter referred to as " PCV ", means a power value applied from an output end of a transceiver of a communication module to an input end of the power amplifier 10.

For example, the PCV may be 5 dB, 10 dB, 20 dB, 30 dB,... , 120dB, 140dB,… The power supply of the power amplifier 10 output terminal also increases as the PCV increases, and the ACPR value of the power amplifier 10 output terminal also increases.

3 is a graph showing the correlation between the output power value and the PCV of the power amplifier 10 according to an embodiment of the present invention.

On the graph, the x axis represents the frequency band (Hz) of the communication channel, and the y axis represents the output power (dB).

Conventionally, as shown in FIG. 3, a method of setting one value from among output power values having various waveforms and repeating the irradiation of the value on the spectral mask corresponding to the PCV has been used. The ACPR value and the EVM value are compared with the values on the spectral masks first, and the PCV is selected in the case of the best match, and the maximum power value corresponding thereto is presented.

Referring to FIG. 3, as the PCV increases, the parallel portions of the output power number waveforms have different angles with gradients having a larger angle (in the order of E waveform, D waveform, C waveform, B waveform, and A waveform). You can see that it is invading the channel of the band.

The power applying unit 120 receives the PCV from the level selection unit 110 and sequentially applies power corresponding to each value to the input terminal of the power amplifier 10.

As the power applying unit 120 sequentially applies the PCV having a gradually larger value, the ACPR of the output terminal of the power amplifier 10 is also increased. In this case, the ACPR value measuring unit 130 includes the power amplifier ( 10) The ACPR value of the output terminal is measured and transmitted to the ACPR value selection unit 140.

4 is a graph illustrating a spectral mask (a) according to the ACPR standard included in the ACPR value selection unit 140 according to an embodiment of the present invention.

In FIG. 4, the thick line means the spectral mask a, and the thin line exemplarily shows an actual ACPR value b having a maximum value while matching the spectral mask. The x-axis of the graph represents a frequency value and the y-axis represents a power value.

The ACPR value selection unit 140 has the spectral mask (a) as shown in FIG. 4, and sets the ACPR value and the value on the spectral mask (a) transmitted from the ACPR numerical measurement unit 130. In comparison, the ACPR value of the nearest value (for example, a value corresponding to a trajectory such as “B” in FIG. 3) is selected without exceeding the threshold of the spectral mask a.

The EVM numerical selector 150 generates an input level numerical value list which has an input level numerical value corresponding to the ACPR numerical value selected by the ACPR numerical value selector as the maximum value.

5 is a diagram illustrating a polar coordinate diagram of an I / Q signal format in which EVM changes as power increases in a power analysis system of an output terminal for a communication module according to an exemplary embodiment of the present invention.

FIG. 5 illustrates a case of a quadrature phase shift keying (QPSK) signal. As shown in FIG. 5A, the RF signal has a phase difference of 90 degrees when passing through an IQ signal modulator, and has a magnitude (I: In-phase). ) Is expressed as a signal vector with rectangular coordinates of a component and a phase (Q: quadrature) component.

However, as the input level power increases, the change occurs as the RF spectral region becomes wider, as shown in FIG.

In other words, as the input level power is increased, error noise and distortion components are intensified, and thus the error width of signal modulation is increased, resulting in a wider spectral region and a greater effect of interference between signals.

FIG. 6 is a polar diagram illustrating a concept of an EVM generated as power increases in a power analysis system of an output terminal for a communication module according to an embodiment of the present invention.

According to Fig. 6, point A shows the theoretical signal position required by the communication module, and point B shows the position of the actual measured signal.

The vector component C shows the error vector between the two signals, and the separation distance D represents the magnitude difference between the theoretical signal and the measured signal.

Although the illustrated measurement signal is illustrated as one point for ease of comparison, the measurement signal may appear as points having a plurality of error vectors as shown in (b) of FIG. 5.

7 is a table illustrating an EVM standard used in a power analysis system of an output terminal for a communication module according to an embodiment of the present invention.

Referring to FIG. 7, data rates and EVMs according to modulation formats of BPSK (Bi-phase Shift Keying), QPSK, 16-state Quadrature Amplitude Modulation (QAM), and 64-state QAM are shown. Has the frequency of the bit stream.

Accordingly, the power analysis system of the output terminal for the communication module according to the present invention aims to find the maximum input level power value within the range of the EVM standard as well as the ACPR standard.

FIG. 8 is a graph illustrating comparison of numerical values used by a power analysis system of an output terminal for a communication module according to an embodiment of the present invention to find an input level power value having a maximum value while simultaneously satisfying an ACPR standard and an EVM standard.

As described above, the EVM value selector 150 generates an input level value list that maximizes the input level value corresponding to the ACPR value selected by the ACPR value selector, which is within the "K" area of FIG. These are the numbers that exist.

Curve “G” in FIG. 8 is the characteristic curve of EVM, and curve “H” shows the characteristic curve of ACPR. In addition, the constant "E" represents the threshold value of the EVM, and the constant "F" represents the threshold value of the ACPR.

Therefore, the ACPR tolerance range "K" is set based on the point where the curve "H" and the constant "F" meet, and the EVM tolerance range "J" is the point where the curve "G" and the constant "E" meet. It is set as a standard.

The EVM value selection unit 150 searches an input level value approaching the threshold of the EVM standard on the list. According to FIG. 8, the input level value is preferably closer to the point "I".

When the searched input level value is transmitted from the EVM value selector 150, the numerical extractor 160 searches for the final PCV corresponding to the plurality of PCVs, and again, the power amplifier 10 corresponding to the searched PCV. Extract the output power value of.

As described above, an operation process contrary to the conventional method is implemented, and according to the present invention, a process for obtaining the maximum output power of the power amplifier 10 may be implemented more simply and efficiently.

On the other hand, the control unit 170 is the level selection unit 110, the power applying unit 120, ACPR value measuring unit 130, ACPR value selection unit 140, EVM value selection unit 150 and numerical extractor It controls the data input and output between the 160 and proceeds the operation process of each component.

In addition, the controller 170 searches the PCV corresponding to the finally selected ACPR value by the numerical extractor 160 and extracts the output power value of the power amplifier 10 before the level selector 110. By repeatedly operating the power applying unit 120, the ACPR numerical measuring unit 130, the ACPR numerical selecting unit 140 and the EVM numerical selecting unit 150, it is more precise (closer to the threshold of the spectrum mask (a) Approaching ACPR values.

Hereinafter, a power analysis method of an output terminal for a communication module according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

9 is a flowchart illustrating a power analysis method of an output terminal for a communication module according to an embodiment of the present invention.

Referring to FIG. 9, first, the ACPR numerical measurement unit 130 receives a spectral mask a according to the ACPR standard (S100). For reference, the spectral mask (a) may be adjusted as needed and programmed into the ACPR numerical measurement unit 130.

Subsequently, the level selector 110 receives a plurality of PCVs (S105), and the power applying unit 120 sequentially inputs power corresponding to the set PCVs to an input terminal of the power amplifier 10. (S110).

When the power corresponding to the PCV is sequentially input, the ACPR value measuring unit 130 measures the ACPR value of the power of the power amplifier 10 output terminal (S115).

In addition, the ACPR value selection unit 140 sequentially compares the ACPR value with a value on the spectral mask a to extract an ACPR value closest to a threshold (S120).

As the ACPR value is extracted, the ACPR value selection unit 140 traces and searches the PCV corresponding to the extracted ACPR value in reverse (S125).

Subsequently, the EVM value selection unit 150 generates and stores a PCV list having the maximum value of the searched PCV (S130), and sequentially applies the PCV on the list to approach the threshold of the EVM standard. The PCV is searched for (S140).

When the PCV is searched, the numerical extractor 160 applies the searched PCV again to extract the output power value of the power amplifier 10 corresponding thereto (S150).

As the output power value of the power amplifier 10 is extracted, impedance matching between input and output terminals of the power amplifier 10 is performed according to the finally selected PCV and output power value, and power setting of the power amplifier is performed. (S160).

The present invention has been described above with reference to its preferred embodiments, which are merely examples and are not intended to limit the present invention, and those skilled in the art to which the present invention pertains should not depart from the essential characteristics of the present invention. It will be appreciated that various modifications and applications are not possible that are not illustrated above. For example, each component specifically shown in the embodiment of the present invention can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

According to the power analysis system of the output terminal for the communication module according to the present invention, the maximum output power value can be derived in a range that conforms to the ACPR standard and the EVM standard, so that power matching of the power amplifier can be efficiently performed. The transmission / reception distance of the RF communication device can be maximized.

In addition, according to the power analysis method of the output terminal for the communication module according to the present invention, since the power of the communication module is maximized and matched to meet the ACPR standard, it is possible to prevent the interference and noise phenomenon between the various communication channels, and thus There is an effect that can improve the transmission and reception quality.

In addition, according to the present invention, there is an effect that can easily produce a high-quality communication module for a short time by significantly reducing the hassle and long working time of the conventional communication module power matching methods.

Claims (6)

Establishing an Adjacent Channel Power Ratio (ACPR) spectrum specification; Setting a plurality of input level values of the power amplifier; Measuring an ACPR value of the power amplifier output stage power as the power having the input level value is input to the power amplifier; Retrieving the input level value corresponding to the case where the ACPR value approaches the threshold of the ACPR spectrum standard; Generating an input level value list having the retrieved input level value as a maximum value, and retrieving an input level value corresponding to an error vector magnitude (EVM) standard by applying the input level value on the list; ; And And extracting an output power value of the power amplifier corresponding to the searched input level value. The method of claim 1, wherein the output power value of the power amplifier is extracted. And the output power value is extracted after the step of setting the input level value and retrieving the input level value according to the EVM standard is repeated. The method of claim 1, wherein the output power value of the power amplifier is extracted. And performing impedance matching between the input and output terminals of the power amplifier based on the retrieved input level value and the extracted output power value. A level selector configured to set a plurality of input level values of the power amplifier; A power applying unit configured to apply power corresponding to the transmitted input level value to an input of the power amplifier; An ACPR value measuring unit measuring an ACPR value of the output stage of the power amplifier to which the input level value is applied; An ACPR value selection unit having an ACPR spectrum standard and selecting an ACPR value closest to the ACPR spectrum standard by comparing the ACPR value transmitted from the ACPR numerical measurement unit with the ACPR spectrum standard; An EVM value selection unit for generating an input level value list corresponding to the selected ACPR value and searching for an input level value approaching a threshold of an EVM standard on the list; And And a numerical extractor extracting an output power value of the power amplifier corresponding to the input level value transmitted from the EVM value selector. The method of claim 4, wherein And a control unit which advances an operation process of the level selecting unit, the power applying unit, the ACPR numerical measuring unit, the ACPR numerical selecting unit, the EVM numerical selecting unit, and the numerical extracting unit. The controller repeatedly functions the level selector, the power applying unit, the ACPR value measuring unit, the EVM value selecting unit, and the ACPR value selecting unit, And the numerical extracting unit receives the input level value finally selected through the repeat function from the EVM value selecting unit. The method of claim 4, wherein the input level value list And an input level value corresponding to the selected ACPR value as the maximum value.

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