KR20110029774A - Apparatus for searching radio frequency - Google Patents

Abstract

PURPOSE: An apparatus for detecting a radio frequency is provided to cut down manufacturing costs by simplifying the number of unnecessary component. CONSTITUTION: An apparatus for detecting a radio frequency includes a power divider(100), a reference power detector, a first frequency signal gain variable part(210), a first power detector(310), a secondary frequency signal gain variable part(220), a second power detector(320), and a central processing unit(400). The reference power detectordetects the electricity of the signal applied from the power divider. The first frequency signal gain variable part detects one of two separated frequency band and changes the gain according to the frequency while attenuating a signal applied from the power divider. The central processing unit calculates the difference the inputted power from the reference power detector and the first and second power detectors and sets a frequency corresponding to the difference between a calculation result and a predetermined frequency.

Description

Frequency Detection Device {Apparatus for Searching Radio Frequency}

The present invention relates to a frequency detecting device used in a base station or a repeater, and more particularly, to a frequency detecting device capable of detecting a frequency using a gain characteristic according to the frequency of an element without using a frequency generator in a frequency detecting process. It is about.

In general, a power amplifier used in a base station or a repeater is for power amplification of an input signal. In order to extract the maximum power, a transistor, which is a main active element, is operated in a saturation region having strong nonlinear characteristics.

However, due to the characteristics of the active device, intermodulation signals are generated due to the nonlinear characteristics near the saturation region, and these intermodulation (IMD) signals act as interference or noise, which degrades the transmission quality, thereby degrading communication quality. .

Therefore, in order to remove the intermodulation signal in the power amplification process, the frequency of the input signal is detected and the linearization technique such as predistortion can be canceled by using the frequency detected in the power amplification process. This results in a high output signal with no intermodulation signal removed.

Figure 1 shows an example of a frequency detection device for detecting the frequency of such an RF input signal.

As shown, the conventional frequency detection apparatus includes a mixer 10 for downconverting a frequency of an RF signal into an intermediate frequency band, a frequency generator 20 for supplying a LO frequency for frequency synthesis to the mixer 10, and a mixer 10. And Saw filters 30 and 31 for filtering out unnecessary frequencies among the frequencies output from the IF amplifier 41 and IF amplifiers 40 and 41 for amplifying intermediate frequencies. Controls the IF detector 50 and the frequency generator 20, which converts the signal strength into a power level signal and outputs the signal to the central processing unit (CPU). The RF frequency inputted according to the power level input from the IF detector 50 is controlled. It consists of a central processing unit 60 to set and output the set frequency value to the CPU of the linearizer.

However, such a conventional RF frequency detection device has many components such as a mixer 10, a frequency generator 20, a saw filter 30, an IF amplifier 41, an IF detector 50, and a separate central processing unit 60. As a result, the circuit structure is complicated and the manufacturing cost is greatly increased.

In addition, since the frequency is converted into a frequency lower than the input frequency (Down Converting), the generated frequency is converted into a sweep to find out the frequency of use. This causes problems in terms of complexity, such as slow response time.

In particular, in the conventional RF frequency detection device, since the oscillator (VCO) is essentially used in the frequency generator 20, it cannot but be sensitive to temperature, and thus, the reliability of the detected signal is inevitably degraded, thereby improving the power amplifier. There was a problem that can not secure the linearity.

The present invention has been made to solve the above-mentioned conventional problems, the object of the present invention is to reduce the unnecessary parts according to the frequency detection and simplify the circuit to greatly reduce the manufacturing cost and simplify the circuit structure RF frequency It is to provide a detection device.

In addition, another object of the present invention is to provide an RF frequency detection device that can achieve accurate frequency detection regardless of the temperature change, because it does not use a frequency oscillator, thereby more reliable linearization.

Furthermore, another object of the present invention is to provide an RF frequency detecting apparatus capable of detecting two frequencies from an input signal.

The above object of the present invention is a power distributor for distributing the input RF signal; A reference power detector for detecting power of a signal applied from the power divider; A first frequency signal gain variable unit which attenuates a signal applied from the power splitter so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A first power detector for detecting power of a signal applied from the first frequency signal gain variable part; A second frequency signal gain variable unit which attenuates a signal applied from the power splitter so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A second power detector for detecting power of a signal applied from the second frequency signal gain variable part; The difference between the reference power detector and the first and second power detectors may be achieved through a frequency detection device including a central processing unit for calculating a difference corresponding to the difference value among pre-stored frequencies. .

In addition, an object of the present invention is a power distributor for distributing the input RF signal; A reference frequency signal gain variable unit which attenuates the signal applied from the power divider and changes a gain of the signal according to a frequency; A reference power detector for detecting power of a signal applied from the reference frequency signal gain variable unit; A first frequency signal gain variable unit which attenuates a signal applied from the power splitter so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A first power detector for detecting power of a signal applied from the first frequency signal gain variable part; A second frequency signal gain variable unit which attenuates a signal applied from the power splitter so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A second power detector for detecting power of a signal applied from the second frequency signal gain variable part; The difference between the reference power detector and the first and second power detectors may be achieved through a frequency detection device including a central processing unit for calculating a difference corresponding to the difference value among pre-stored frequencies. ..

And an object of the present invention is a power distributor for distributing the input RF signal; A reference power detector for detecting power of a signal applied from the power divider; An RF switch for switching a signal applied from the power divider; A first frequency signal gain variable unit which attenuates the signal applied from the RF switch so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A first power detector for detecting power of a signal applied from the first frequency signal gain variable part; A second frequency signal gain variable unit which attenuates the signal applied from the RF switch so as to detect one of the two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A second power detector for detecting power of a signal applied from the second frequency signal gain variable part; The difference between the reference power detector and the first and second power detectors may be calculated through a frequency detection device including a central processing unit for calculating a difference corresponding to the difference value among pre-stored frequencies. .

Furthermore, an object of the present invention is to provide a power divider for distributing an input RF signal; A reference power detector for detecting power of a signal applied from the power divider; A first RF switch for distributing a signal input from the power distributor; A first frequency signal gain variable unit which attenuates the signal applied from the first RF switch so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A second frequency signal gain variable unit which attenuates the signal applied from the first RF switch so as to detect another frequency band of two spaced apart frequencies, and whose gain is changed according to the frequency; A second RF switch for switching a signal applied from the first and second frequency signal gain variable parts; A first power detector for detecting power of the attenuated signal applied from the first RF switch; The difference between the reference power detector and the first power detector can be achieved by using a frequency detection device including a central processing unit for calculating a difference corresponding to the difference value among pre-stored frequencies.

The present invention has a very useful effect of greatly reducing the number of components according to the frequency detection to simplify the circuit structure and significantly reduce the manufacturing cost.

According to the present invention, since two frequencies can be set through the first and second frequency signal gain variable parts and the first and second power detectors, multicarriers can be realized.

Since the present invention does not use a temperature-sensitive device such as a frequency oscillator, accurate frequency detection is possible, and thus there is a very useful effect of ensuring more reliable linearity.

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

<First Embodiment>

FIG. 2 is a block diagram to which the frequency detecting device of the present invention is applied, and FIG. 3 is a block diagram showing the configuration of the frequency detecting device. As shown in the present invention, a power divider 100 and a reference power detector 300 are shown. The first and second frequency signal gain variable parts 210 and 220, the first and second power detectors 310 and 320, and the central processing unit 400 are provided.

First, the power divider 100 distributes the power of the input RF signal by distributing the power and outputs the power to the reference power detector 300 and the first and second frequency signal gain variable parts 210 and 220.

The reference power detector 300 detects the power level of the signal applied from the power divider 100 and outputs the power level value to the CPU 400.

The first frequency signal gain variable unit 210 attenuates a signal so as to detect a frequency of any one of two spaced apart frequencies included in the signal applied from the power divider 100. For example, the signal applied from the power divider 100 is attenuated, but low pass is output to the first power detector 310.

The first power detector 310 detects the power level of the low pass signal by the first frequency signal gain variable unit 210 and outputs the power level value to the CPU 400.

The second frequency signal gain variable unit 220 attenuates a signal so as to detect a frequency of another band of two spaced apart frequencies included in the signal applied from the power divider 100. For example, the signal applied from the power divider 100 is attenuated and output to the high path seeker second power detector 220.

The second power detector 320 detects the power level of the high pass signal by the second frequency signal gain variable unit 220 and outputs the power level value to the CPU 400.

Here, the first and second frequency signal gain variable parts 210 and 220 allow the input signal to have a low pass and a high pass, respectively.

In addition, the first and second frequency signal gain variable units 210 and 220 may use a band pass filter, a low pass filter, and a high pass filter to attenuate the applied signal. It is preferable to use a filter, but it is also possible to use a passive element or an active element having a desired loss and gain depending on the frequency in addition to the filter.

The CPU 400 calculates a difference between power values input from the reference power detector 300 and the first and second power detectors 310 and 320 to set a frequency corresponding to the difference value among pre-stored frequencies. In this case, it is preferable to use a lookup table to set the frequency according to the difference in the power values.

The central processing unit 400 may simply use a central processing unit having a reader function, but it is preferable to use a linearizing central processing unit (CPU) for simple circuit configuration and cost reduction.

4 illustrates an example of first and second lookup tables illustrating differences between power values of the reference power detector 300 and the first and second power detectors 310 and 320 and their corresponding frequencies when a specific frequency signal is input. It is shown.

For example, when a specific frequency signal is input, a power value of the first power detector 310 low pass by the first frequency signal gain variable unit 210 and a power value of the reference power detector 300 have a difference. do. Therefore, when the central processing unit 400 calculates the difference between the two power values and obtains -8.92, the central processing unit 400 sets 2110MHz corresponding to -8.92 in the first lookup table as the frequency and uses the frequency for predistortion linearization.

In addition, the CPU 400 calculates a difference between the power value of the second power detector 320 and the power value of the reference power detector 300 that are high pass by the second frequency signal gain variable unit 220. When -10.8 is obtained, 2170MHz corresponding to -10.8 is set as the frequency in the second lookup table and used as the frequency for predistortion linearization.

As described above, when the input signal includes two frequencies spaced apart from each other, as in the example of 2110 MHz and 2170 MHz, the present invention detects each of the signals through low pass and high pass, thereby realizing multi-carrier by setting two frequency bands. Nonlinear components resulting from linearization can also be efficiently removed.

Furthermore, the present invention according to the first embodiment does not use a frequency oscillator unlike the prior art, which not only reduces manufacturing costs and simplifies the circuit, but is also stable and accurate even when the power is changed and the temperature is changed, such as the maximum time or the minimum time. Frequency detection can be performed. Therefore, call quality can be improved through more reliable linearization.

Second Embodiment

5 shows another embodiment of the present invention, which is substantially the same as the configuration of the first embodiment, except that the reference frequency signal gain variable part having attenuation characteristics different from those of the first and second frequency signal gain variable parts 210 and 220 is shown. There is a difference in that 200 is installed at the input of the reference power detector 300.

As described above, since the reference frequency signal gain variable part 200 and the first and second frequency signal gain variable parts 210 and 220 have different gain characteristics, the reference power detector 300 and the first and second powers are different from each other. The power level values output from the detectors 310 and 320 are different, and the CPU 400 calculates the difference value and sets the frequency of the lookup table corresponding thereto.

The frequency stored in the lookup table and a value corresponding to each frequency are determined by the gain characteristics of the reference frequency signal gain variable unit 200 and the first and second frequency signal gain variable units 210 and 220. Other values can be stored, but the effect is the same because the way they work is the same.

Third Embodiment

6 shows another embodiment of the present invention, which is substantially the same as that of the first embodiment, except that the first and second frequency signal gains are variable by switching the output signal of the power divider 100 through the RF switch 500. There is a difference in that it is input to the unit (210, 220).

Fourth Embodiment

7 shows another embodiment of the present invention, which is substantially the same as the configuration of the third embodiment, but uses the first RF switch 510 and the second RF switch 520 in terms of reducing the number of power detectors. There is a difference.

As described above, since the second RF switch 520 switches both signals of the first and second frequency signal gain variable parts 210 and 220, the first power detector 310 detects the power level of each signal. As a result, the number of power detectors can be reduced, thereby simplifying circuit structure and reducing costs.

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

1 is a block diagram showing a conventional frequency detection device.

Figure 2 is a block diagram to which the frequency detection device of the present invention is applied.

Figure 3 is a block diagram showing a frequency detection apparatus according to the present invention.

4 is a table showing an example of a lookup table according to the present invention;

5 to 7 are block diagrams showing another embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: power divider 200: reference frequency signal gain variable part

210,220: first and second frequency signal gain variable part

300: reference power detector

310,320: first and second power detector

400: central processing unit

500,510,520: RF Switch

Claims (10)

A power distributor 100 for distributing the input RF signal; A reference power detector (300) for detecting power of a signal applied from the power divider (100); A first frequency signal gain variable unit 210 for attenuating a signal applied from the power splitter 100 so as to detect one of two frequency bands spaced apart from each other, but having a gain of the signal changed according to a frequency; A first power detector (310) detecting power of a signal applied from the first frequency signal gain variable unit (210); A second frequency signal gain varying unit 220 which attenuates the signal applied from the power splitter 100 so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A second power detector 320 for detecting power of a signal applied from the second frequency signal gain variable unit 220; The CPU 400 calculates a difference between power values input from the reference power detector 300 and the first and second power detectors 310 and 320 and sets a frequency corresponding to the difference value among pre-stored frequencies. Frequency detection device comprising a. A power distributor 100 for distributing the input RF signal; A reference frequency signal gain variable unit 200 which attenuates the signal applied from the power divider 100 and whose gain is changed according to frequency; A reference power detector (300) for detecting power of a signal applied from the reference frequency signal gain variable unit (300); A first frequency signal gain variable unit 210 for attenuating a signal applied from the power splitter 100 so as to detect one of two frequency bands spaced apart from each other, but having a gain of the signal changed according to a frequency; A first power detector (310) detecting power of a signal applied from the first frequency signal gain variable unit (210); A second frequency signal gain varying unit 220 which attenuates the signal applied from the power splitter 100 so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; A second power detector 320 for detecting power of a signal applied from the second frequency signal gain variable unit 220; The CPU 400 calculates a difference between power values input from the reference power detector 300 and the first and second power detectors 310 and 320 and sets a frequency corresponding to the difference value among pre-stored frequencies. Frequency detection device comprising a. A power distributor 100 for distributing the input RF signal; A reference power detector (300) for detecting power of a signal applied from the power divider (100); An RF switch 500 for switching a signal applied from the power splitter 100; A first frequency signal gain variable unit 210 attenuating the signal applied from the RF switch 500 so as to detect any one of two frequency bands spaced apart from each other, and having a gain of the signal changed according to the frequency; A first power detector 310 for detecting the power of the signal applied from the first frequency signal gain variable unit 210 A second frequency signal gain variable unit 220 which attenuates the signal applied from the RF switch 500 so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; Second power detector 320 for detecting the power of the signal applied from the second frequency signal gain variable unit 220 The CPU 400 calculates a difference between power values input from the reference power detector 300 and the first and second power detectors 310 and 320 and sets a frequency corresponding to the difference value among pre-stored frequencies. Frequency detection device comprising a. A power distributor 100 for distributing the input RF signal; A reference power detector (300) for detecting power of a signal applied from the power divider (100); A first RF switch (510) for distributing a signal input from the power splitter (100); A first frequency signal gain variable unit 210 which attenuates the signal applied from the first RF switch 510 so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; ; A second frequency signal gain variable unit 220 which attenuates the signal applied from the first RF switch 510 so as to detect one of two frequency bands spaced apart from each other, but whose gain is changed according to the frequency; ; A second RF switch 520 for switching a signal applied from the first and second frequency signal gain variable parts 210 and 220; A first power detector (310) for detecting power of the attenuated signal applied from the second RF switch (520); The CPU 400 calculates a difference between power values input from the reference power detector 300 and the first power detector 310 and sets a frequency corresponding to the difference value among pre-stored frequencies. Frequency detection device comprising a. The method according to any one of claims 1 to 4, wherein the reference frequency signal gain variable unit 200 and the first and second frequency signal gain variable units 210 and 220 may have different gain characteristics at a desired frequency. Frequency detection device, characterized in that made of any one of a passive element and an active element. The method according to any one of claims 1 to 4, wherein the reference signal gain variable unit 200 and the first and second frequency signal gain variable units 210 and 220 can have different gain characteristics at a desired frequency. A frequency detection device comprising a combination of a passive element and an active element. The frequency detection device according to any one of claims 1 to 4, wherein the reference signal gain variable part (200) and the first and second frequency signal gain variable parts (210) are filters. The method according to any one of claims 1 to 4, wherein the first frequency signal gain variable unit 210 is a low pass filter, and the second frequency signal gain variable unit 220 is a high pass filter. Frequency detection device. The method according to any one of claims 1 to 4, wherein the first frequency signal gain variable unit 210 is a high pass filter, and the second frequency signal gain variable unit 220 is a low pass filter. Frequency detection device. 5. A frequency detection device as claimed in any preceding claim, wherein said central processing unit (400) is a central processing unit (CPU) of a linearizer.

Images