KR20060120361A - Portable installation for detecting passive intermodulation distortion signal and method thereof - Google Patents

Abstract

A portable PIMD(Passive Inter Modulation Distortion) signal measurement device and a method thereof are provided to allow a measurement device for a PIMD signal to be realized in portable type, thereby measuring PIM of aerial equipment in an installation field. A PLL(Phase Locked Loop)(203) supplies reference signals consisting of the first frequency signal and the second frequency signal. A power combiner(207) synthesizes power for the respective reference signals having predetermined attenuation characteristics. The first power detector(209) detects the signal level of an output signal of the combiner(207). A duplexer(211) passes the reference signals in forward direction, and passes the third IM(Inter Modulation) signal abandoned from the reference signal in reverse direction. An LNA(Low Noise Amplifier)(213) performs low noise amplification for the third IM signal. The second power detector(215) detects signal level of the third IM signal. A controller(201) controls each frequency setup corresponding to the reference signals, calculates a difference value between the signal levels by comparing the signal level of the detector(209) with the signal level of the detector(215), and provides the calculated results to a display(219).

Description

PORTABLE INSTALLATION FOR DETECTING PASSIVE INTERMODULATION DISTORTION SIGNAL AND METHOD THEREOF

1 is a graph showing a measurement signal for an intermodulation distortion signal.

2 is a block diagram showing a measuring apparatus according to the present invention.

3 is a flowchart for explaining the main operation of the present invention.

<Explanation of symbols for main drawings>

201: controller 203: phase locked loop

205 attenuation section 207 power coupling section

209: first power detector 211: duplexer

213: low noise amplifier 215: second power detector

217: keypad 219: display unit

221 amplifier 223 attenuator

225: high power amplifier

The present invention relates to a measuring device for a passive element intermodulation distortion (hereinafter, referred to as PIMD) signal of an aerial equipment. More specifically, the present invention relates to a basic signal (f1, f2) for PIM measurement. After generating randomly and measuring the third IM signals 2f2-f1 and 2f1-f2 corresponding to the basic signals f1 and f2, the PIM of the measurement target element is subtracted by subtracting the basic signal and the third IM signal. The present invention relates to a portable PIM measuring apparatus and method capable of providing portability of a PIM measuring apparatus based on a simplified structure by providing only a calculation result for PIM.

As demand for mobile communication services increases, frequency band expansion and FA (Frequency Allocation) are increasingly used to accommodate them. As a result, distortion occurs due to nonlinearity of the device. In particular, quality degradation of the service signal is caused by an intermodulation (IMD) signal generated between FAs of a transmission signal. Previously, research on IMD signals by active devices has been conducted, but recently, research on IMD signals by passive devices, that is, passive intermodulation (PIMD) signals, has been conducted due to an increase in the output level due to the expansion of the service area. It is actively done.

Looking at the problems caused by the PIMD signal, depending on the power level of the signal, if a certain level of PIMD signal is generated, the communication system treats the noise signal as a data signal, causing a drop in the call quality or a disconnection of the call. do. In severe cases, the frequency band at which the PIMD signal occurs is blocked at all. This is a serious waste in terms of frequency resources, and in the case of service providers, the frequency band allocated to each user increases, resulting in the loss. Therefore, in terms of the efficiency of frequency utilization, elimination of the PIMD signal is urgent.

Although the cause of PIMD signal varies from device to device, it is classified into material nonlinearity and contact nonlinearity, which basically constitute passive devices, and methods to reduce the generation of PIMD signals in terms of materials and structures are being developed. . Current mobile communication base station and relay station system is using a duplex (Duplexer) for separating and combining the transmission and reception signals. However, in case of duplex, PIMD characteristics are deteriorated at the T-junction that combines the transmission and reception signals, and in case of the divider, which is frequently used in the relay station, an isolation resistor is input when a high power level is input. PIMD properties deteriorate at the junction of.

The occurrence of these PIMD signals is caused by RF components, which are classified into contact nonlinearity and material nonlinearity. The causes of contact nonlinearity include the bonding capacity of the thin oxide layer between the conductors, the tunnel effect by the semiconductor action between the conductors in the metal contact, the micro-discharge due to the gaps and micro cracks between the metals, Nonlinearities associated with metal particles, constriction resistances from metal bonds, etc.The causes of material nonlinearities include hysteresis effects such as nickel, iron, and cobalt, internal shottkey effects, and limited conductivity in conductors. And thermal heating.

As described in Equation 1, the third order terms of the input frequency cosω1 + sinω2 are as follows, and the 2ω1-ω2 and 2ω2-ω1 frequencies are adjacent to ω1 and ω2, which greatly affect the system.

[Equation 1]

(Acosω1t + Bcosω2t) ^ 3

= (3A ^ 3/4 + 3AB ^ 2/2) cosω1t + (3A ^ 2B / 2 + 3B ^ 3/4) cosω2t + A ^ 3 / 4cos3ω1 + B ^ 3 / 2cos3ω2 + 3A ^ 2B / 4cos (2ω1 + ω2) t + 3AB ^ 2 / 4cos (ω1 + 2ω2) t + 3A ^ 2B / 4cos (2ω1-ω2) t + 3AB ^ 2 / 4cos (2ω2-ω1) t

In addition, as shown in FIG. 1, when 2f2-f1 and 2f1-f2 are in a reception band when the input / output frequency is used in a single port, the third-order IM functions as reception noise. The unit of PIM is represented by the ratio of the signal level of F1 or F2 and the signal level of 2F2-F1 or 2F1-F2. For example, if F1 is 40dBm / 30KHz and 2F2-F1 is -100dBm / 30KHz, the PIM of this measuring device is 140dB.

However, in order to measure PIM as described above, a signal generator for generating signals of F1 and F2 and a spectrum analyzer for measuring levels of 2F2-F1 or 2F1-F2 are required. It is difficult to measure the overall PIM of aerials installed in the field because it does not have a structure that can be used.

The present invention was created to solve the above problems, and an object of the present invention is to implement a PIM of the aerial equipment at the installation site by implementing a portable device for measuring the passive element intermodulation distortion (PIMD) signal. The present invention provides a portable passive element intermodulation distortion signal measuring apparatus and method which can be measured.

Another object of the present invention is to measure the basic signals f1 and f2 and the third order IM signals 2f1-f2 and 2f2-f1 without using a spectrum analyzer when measuring PIM of an aerial equipment. The present invention provides a portable passive element intermodulation distortion signal measuring apparatus and method capable of achieving a lighter weight and a smaller size of a system by displaying only a subtraction result.

Portable passive element intermodulation distortion signal measuring apparatus according to the first aspect of the present invention for achieving the above object, in the measuring apparatus for the passive element intermodulation distortion signal (PIMD), a display for displaying any measurement results A housing having a predetermined shape and including a portion; And generating, by the housing, a reference signal having a frequency of a measurement band, applying the reference signal to a measurement object, and subtracting the third IM signal level derived from the measurement object and the signal level of the reference signal. And a PIMD measurement system which calculates and subtracts the subtraction result into the measurement result of the passive element intermodulation distortion signal PIMD.

According to a preferred embodiment of the present invention, the PDM measurement system, the phase locked loop for supplying a reference signal consisting of the first frequency signal f1 and the second frequency signal f2 in response to the set reference frequency signal PLL (Phase Locked Loop); A power combiner for synthesizing power of the respective reference signals; A first power detector for detecting a signal level of the output signal of the power combiner; A duplexer for forwarding the reference signal in a forward direction and for passing a third order IM signal reversed from the reference signal in a reverse direction; A low noise amplifier (LNA) for performing low noise amplification on the third IM signal; A second power detector connected to an output terminal of the low noise amplifier for detecting a signal level of the third IM signal; And controlling each frequency setting corresponding to the reference signal in response to a control signal input from the keypad, and comparing a signal level of the first power detector with a signal level of the second power detector to compare the signal level with each other. And a control unit for providing a calculation result to the display unit.

In addition, an attenuator for attenuating the reference signal to a predetermined level may be linked to a front end of the power coupling unit.

The attenuator may further include: an amplifier AMP provided to amplify the first frequency signal f1 and the second frequency signal f2 to a predetermined level; An attenuator for attenuating the signal size of the output level of each amplifier; And a high power amplifier (HPA) for amplifying and outputting the output signal of the attenuator to a predetermined signal level.

Further, the first frequency signal f1 and the second frequency signal f2 corresponding to the reference signal are frequency bands to be measured and are CW signals selected from 25KHz to 35KHz band.

On the other hand, the measuring method of the portable passive element intermodulation distortion signal measuring apparatus according to the second aspect of the present invention for achieving the above object, in the measuring method for the passive element intermodulation distortion signal (PIMD), a) to be measured Generating a reference signal of a frequency band; b) detecting a signal level with respect to the reference signal; c) detecting a third IM signal induced from the measurement object by the reference signal; d) detecting a signal level for the third IM signal; And e) calculating signal level differences between the reference signal and the third-order IM signal, and assuming the calculation result as a measurement result for the passive element intermodulation distortion signal PIMD.

According to a preferred embodiment of the present invention, step b) comprises: b-1) amplifying the first frequency signal f1 and the second frequency signal f2 to a predetermined level; b-2) attenuating the signal magnitude with respect to the output level of the amplified signal, respectively; b-3) performing high power amplification on each of the attenuated signals; b-4) synthesizing each high power amplified signal; And b-5) detecting a signal level with respect to the power of the synthesized signal.

In addition, the step c) further comprises the step c-1) performing a low noise amplification for the noise cancellation for the third IM signal.

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

Figure 2 is a block diagram showing a portable passive element intermodulation distortion signal measuring apparatus according to the present invention. As shown, a phase locked loop 203 (PLL-Phase Locked Loop) for supplying a reference signal composed of the first frequency signal f1 and the second frequency signal f2 in response to the set reference frequency signal; An attenuator 205 for imparting respective attenuation characteristics to the reference signal, a power combiner 207 for synthesizing power for each reference signal having a predetermined attenuation characteristic, and the power combiner ( A first power detector 209 for detecting a signal level with respect to the output signal of 207, and a duplexer 211 for passing the reference signal forward and a third IM signal derived from the reference signal in a reverse direction ), A low noise amplifier 213 (LNA) for performing low noise amplification on the third IM signal, and an output terminal of the low noise amplifier 213 to detect the signal level of the third IM signal. Second power In response to a control signal input from the output unit 215 and the keypad 217, each frequency setting corresponding to the reference signal is controlled, and the signal level of the first power detection unit 209 and the second power detection unit ( The control unit 201 is configured to compare the signal levels of the signal 215 to calculate a difference value of the signal level, and to provide the calculation result to the display unit 219.

The first frequency signal f1 and the second frequency signal f2 corresponding to the reference signal represent a frequency band to be measured and are CW signals of a 30 KHz band. The attenuator 205 includes an amplifier 221 (AMP) provided to amplify the first frequency signal f1 and the second frequency signal f2 to a predetermined level. An attenuator 223 for attenuating the signal level with respect to the output level of the 221 and a high power amplifier 225 HPA for amplifying and outputting the output signal of the attenuator 223 to a predetermined signal level.

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

3 is a flowchart for explaining the operation of the present invention. First, the user enters the step S301 to carry the measuring device according to the invention, which is close to the measurement object. The user sets the reference frequency corresponding to the reference signal by using the keypad 217. The control unit 201 controls the oscillation of the frequency with the phase locked loop unit 203 in response to user setting information. In step S303, the phase locked loop unit 203 transmits a fixed frequency signal by activating an internal voltage control oscillator (VCO) based on a frequency control command of the controller 201.

The frequency oscillation is a CW signal of 30 KHz, which is a frequency band to be measured, and the phase locked loop unit 203 oscillates the first frequency signal f1 and the second frequency signal f2 of the 30 KHz band. In operation S305, each reference signal corresponding to the first frequency signal f1 and the second frequency signal f2 is applied to the attenuation unit 205.

The attenuator 205 amplifies the reference signal to an arbitrary signal level. The amplification process is amplified to a predetermined size via the signal amplifier 221 and then applied to the attenuator 223. The attenuator 223 attenuates the power to the reference signal and is processed into a signal having a size of 30 dBm to 40 dBm so as to correspond to a CW signal in a band of 25 to 35 KHz, preferably 30 KHz. The reference signal output through the attenuator 223 is provided to the high power amplifier 225 as a normalized signal.

The high power amplifier 225 amplifies the reference signal to a high power of a predetermined level, and is respectively performed on the first frequency signal f1 and the second frequency signal f2. In operation S307, the power combiner 207 synthesizes the first and second frequency signals f1 and f2. The synthesized reference signal is supplied to the first power detector 209. This is the step S309, the first power detector 209 measures the amount of power for the combined signal of the first frequency signal f1 and the second frequency signal f2, the measurement result is applied to the controller 201, The controller 201 stores the result information in an internal memory or a register.

In addition, the reference signal synthesized by the power combiner 207 is applied to the measurement object through the duplexer 211. The duplexer 211 includes a Tx stage for supplying a reference signal to the measurement target and an Rx stage for receiving an intermodulation distortion signal from the measurement target. Accordingly, the reference signal is connected to the Tx terminal of the duplexer 211. The output terminal of the duplexer 211 includes a predetermined cable assembly, and the reference signal is applied to the measurement object through the cable assembly. As a result, in step S311, the reference signal, that is, the first frequency signal f1 and the second frequency signal f2, supplied to the measurement object through the duplexer 211 consumes energy without intermodulation distortion.

In operation S313, the Rx terminal of the duplexer 211 receives the third IM signal induced from the measurement target by the reference signal. The third IM signal is an intermodulation distortion signal generated by the passive element and is induced by the reference signal. The third IM signal is one of the frequency bands most adversely affecting the measurement environment among the intermodulation distortion signals, that is, the frequency signals of the 2f1-f2 and 2f2-f1 bands. The intermodulation distortion signal (PIMD) requires a plurality of field-specific measurements, and the measurement applied in the present invention among the antennas & Accessories, Filter Products, Connectors, Cables & Connector-Cables Assemblies, which are a number of measurement fields, refers to the Antennas & Accessories group. Include.

In step S315, the duplexer 211 removes harmonic components and noise components generated by nonlinearity through the low noise amplifier 213 through the intermodulation distortion signal. In step S317, the output of the low noise amplifier 213 is supplied to the second power detector 215. The second power detector 215 detects the level of the third IM signal corresponding to the harmonic component and the noise component. The detection result of the third IM signal level is supplied to the control unit 201. The control unit 201 stores the third IM signal level in a predetermined memory or register.

The control unit 201 proceeds to step S319 to calculate the difference between the third IM signal level with respect to the reference signal level. In other words, the third IM signal level is subtracted from the reference signal level. The control unit 201 stores the subtraction result in an internal memory. Here, the subtraction result is assumed to be a passive element intermodulation distortion signal PIMD. If necessary, the controller 201 may store a subtraction result of the passive element intermodulation distortion signal, a measurement location, a measurement time, and the like.

The user inputs a measurement location, a measurement time, and the like for the passive element intermodulation distortion signal using the keypad 217. In operation S321, the control unit 201 provides the above-described subtraction result, a measurement place, a measurement time, and the like to the display panel 219.

As described above, the portable passive element intermodulation distortion signal measuring apparatus and method according to the present invention provides a reference frequency signal set by a user in a phase locked loop (PLL), and a reference signal corresponding to the reference frequency signal is measured. After being applied to an object, the signal level of the intermodulation distortion signal (third IM signal) derived from the subtraction signal is subtracted from the signal level of the reference signal, and the result is displayed numerically or graphically. As the system is implemented, the spectral analysis of the passive element intermodulation distortion signal (PIMD) is not required, thereby providing the effect of miniaturization and portability of the system.

In addition, as the detection device for the inter-modulation distortion signal is miniaturized, not only the PIM of the entire aerial can be measured in the field, but also there is an effect of improving the quality of the aerial facility.

What has been described above is only an embodiment of a portable passive element intermodulation distortion signal measuring apparatus according to the present invention, and is not limited to the embodiment of the present invention, and the scope of the present invention as claimed in the following claims Without departing from the scope of the present invention, those skilled in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (17)

In the measuring device for the passive element intermodulation distortion signal (PIMD), A housing having a predetermined shape, the display unit including a display unit for displaying an arbitrary measurement result; And A reference signal having a frequency of a measurement band is generated by the housing, the reference signal is applied to a measurement object, and a result of subtracting the third IM signal level derived from the measurement object and the signal level of the reference signal is calculated. And a PIMD measurement system which assumes a subtraction result as the measurement result of the passive element intermodulation distortion signal (PIMD). The portable passive device intermodulation distortion signal measuring apparatus according to claim 1, wherein the frequency of the measurement band is settable by a user. The apparatus of claim 1, wherein the subtraction result is graphic information and provides the graphic information to the display unit. 2. The portable passive element intermodulation distortion signal measuring apparatus according to claim 1, wherein the subtraction result is textual numerical information and provides the numerical information to the display unit. The PMI measurement system of claim 1, wherein A phase locked loop (PLL-Phase Locked Loop) for supplying a reference signal composed of the first frequency signal f1 and the second frequency signal f2 in response to the set reference frequency signal; A power combiner for synthesizing power of the respective reference signals; A first power detector for detecting a signal level of the output signal of the power combiner; A duplexer for forwarding the reference signal in a forward direction and for passing a third order IM signal reversed from the reference signal in a reverse direction; A low noise amplifier (LNA) for performing low noise amplification on the third IM signal; A second power detector connected to an output terminal of the low noise amplifier for detecting a signal level of the third IM signal; And In response to a control signal input from the keypad, each frequency setting corresponding to the reference signal is controlled, and the signal level of the first power detector and the signal level of the second power detector are compared with each other to determine a difference value of the signal level. And a control unit for calculating and providing the calculation result to the display unit. The apparatus of claim 5, wherein an attenuator for attenuating the reference signal to a predetermined level is coupled to a front end of the power coupling unit. 7. The apparatus of claim 6, wherein the attenuator comprises: an amplifier (AMP) provided respectively to amplify the first frequency signal (f1) and the second frequency signal (f2) to a predetermined level; An attenuator for attenuating the signal size of the output level of each amplifier; And And a high power amplifier (HPA) for amplifying and outputting the output signal of the attenuator to a predetermined signal level. The method of claim 5 or 7, wherein the first frequency signal f1 and the second frequency signal f2 corresponding to the reference signal is a frequency band to be measured, it is a CW signal selected from 25KHz to 35KHz band Portable passive element intermodulation distortion signal measuring apparatus characterized in that. 9. The portable passive element intermodulation distortion signal measurement according to claim 8, wherein the first frequency signal f1 and the second frequency signal f2 corresponding to the reference signal are CW signals selected in the 30 KHz band. Device. In the measuring method for the passive element intermodulation distortion signal (PIMD), a) generating a reference signal of a frequency band to be measured; b) detecting a signal level with respect to the reference signal; c) detecting a third IM signal induced from the measurement object by the reference signal; d) detecting a signal level for the third IM signal; And e) calculating a signal level difference between the reference signal and the third-order IM signal, and assuming the calculation result as a measurement result of the passive element intermodulation distortion signal (PIMD). METHOD OF MEASUREMENT OF A MODIFICATION Distortion Signal Measuring Device. 11. The method of claim 10, wherein the reference signal of step a) is settable by a user. The portable passive device according to claim 11, wherein the reference signal is a first frequency signal f1 and a second frequency signal f2 of a frequency band to be measured, and is a CW signal selected from 25KHz to 35KHz band. METHOD OF MEASUREMENT OF AN INTERMOMOUSLY Distortion Signal Measuring Device. The method of claim 10 or 12, wherein step b) b-1) amplifying the first frequency signal f1 and the second frequency signal f2 to a predetermined level; b-2) attenuating the signal magnitude with respect to the output level of the amplified signal, respectively; b-3) performing high power amplification on each of the attenuated signals; b-4) synthesizing each high power amplified signal; And b-5) A measuring method of a portable passive element intermodulation distortion signal measuring apparatus comprising the step of detecting a signal level with respect to the power of the synthesized signal. 12. The method of claim 10, wherein the measurement result of step e) is provided as graphic information. 12. The method of claim 10, wherein the measurement result of step e) is provided as textual numerical information. 16. The portable passive element intermodulation distortion signal measurement according to any one of claims 10, 14 and 15, wherein the measurement result of step e) further includes a measurement place, a measurement time, and a measurer information. Method of measurement of the device. The method of claim 10, wherein step c) c-1) performing a low noise amplification for removing the noise of the third IM signal.

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