CN113904740B - System and method for calibrating 5G base station test based on reverberation room - Google Patents
System and method for calibrating 5G base station test based on reverberation room Download PDFInfo
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- CN113904740B CN113904740B CN202111164509.6A CN202111164509A CN113904740B CN 113904740 B CN113904740 B CN 113904740B CN 202111164509 A CN202111164509 A CN 202111164509A CN 113904740 B CN113904740 B CN 113904740B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/309—Measuring or estimating channel quality parameters
- H04B17/318—Received signal strength
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/10—Monitoring; Testing of transmitters
- H04B17/11—Monitoring; Testing of transmitters for calibration
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/20—Monitoring; Testing of receivers
- H04B17/21—Monitoring; Testing of receivers for calibration; for correcting measurements
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
- H04B17/30—Monitoring; Testing of propagation channels
- H04B17/309—Measuring or estimating channel quality parameters
- H04B17/318—Received signal strength
- H04B17/327—Received signal code power [RSCP]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
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- Testing Electric Properties And Detecting Electric Faults (AREA)
Abstract
The invention provides a calibration system and a method for a 5G base station test based on a reverberation room. The system comprises: a shielding housing defining an interior cavity of the reverberation chamber, the interior cavity including a working region of the reverberation chamber; one or more mode agitators; the calibration substitute of the base station to be tested is arranged in the working area; a reference antenna for transmitting a calibration signal at the time of calibration; a measurement antenna for receiving a calibration signal; the calibration equipment is used for calculating according to the signals transmitted by the reference antenna and the signals received by the measurement antenna to obtain a target calibration result; the calibration substitute is selected so that the difference value between a target calibration result obtained based on the calibration substitute and a target calibration result obtained based on the base station to be tested under the same calibration condition falls within the uncertainty requirement range of the 5G base station test based on the reverberation room. The invention adopts the calibration substitute to perform advanced calibration and one-time calibration on the premise of meeting certain measurement uncertainty, thereby saving test time and cost.
Description
Technical Field
The invention relates to the technical field of base station testing, in particular to a system and a method for calibrating a 5G base station test based on a reverberation room.
Background
When testing the OTA (Over-the-Air) radio frequency index of a 5G base station in a reverberation room at present, according to the testing principle of the reverberation room, the general method in the industry is to put the base station to be tested into the reverberation room to participate in path calibration, and for different base stations to be tested, path calibration needs to be carried out again each time, and then the test is carried out by using the position and configuration which are completely the same as the calibration. When the test frequency points are more, a long time is required to be consumed for calibration before each test, and expensive high-frequency meters required for calibration, including a high-frequency signal source, a high-frequency spectrometer, a high-frequency network analyzer and the like, occupy a long time, consume the use of assets in an intangible way, and cause great waste of test time and test cost.
Disclosure of Invention
The present invention has been made in view of the above problems, and aims to provide a calibration system and method for reverberation room based 5G base station testing which overcomes or at least partially solves the above problems.
An object of the present invention is to provide a calibration system and method for testing a 5G base station based on a reverberation room, which uses a calibration substitute to replace a base station to be tested to perform advanced calibration and one-time calibration, thereby greatly saving test time and test cost.
It is a further object of the present invention to further enhance the feasibility and ease of the calibration system and method.
In particular, according to an aspect of an embodiment of the present invention, there is provided a calibration system for a 5G base station test based on a reverberation chamber, including:
A shielding enclosure defining an interior cavity of the reverberation chamber, the interior cavity including a working region of the reverberation chamber;
one or more mode stirrers disposed in the internal cavity outside the working area for changing the mode of electromagnetic waves in the internal cavity;
The calibration substitute of the base station to be tested is arranged in the working area;
a reference antenna provided at one side of the calibration substitute for transmitting a calibration signal at the time of calibration;
a measurement antenna disposed on the other side of the calibration substitute for receiving the calibration signal; and
The calibration device is respectively connected with the reference antenna and the measurement antenna and is used for calculating according to signals transmitted by the reference antenna and signals received by the measurement antenna to obtain a target calibration result;
And the calibration substitute is selected so that the difference value between a target calibration result obtained based on the calibration substitute and a target calibration result obtained based on the base station to be tested under the same calibration condition falls within the uncertainty requirement range of the 5G base station test based on the reverberation chamber.
Optionally, the calibration substitute is any one of the following:
a first housing having an external dimension comparable to the base station under test and made of a material having a dielectric constant less than 3.6;
a second housing having an external dimension comparable to the base station under test and comprising an external metal wrapping layer having a thickness of not more than 1 mm;
and a base station tooling assembly in a state of not installing the base station.
Optionally, the first housing is a housing made of a weakly polar or non-polar polymeric material having a dielectric constant less than 3.6; or (b)
The first housing is a carton.
Optionally, the polymeric material is polypropylene or glass fiber reinforced polypropylene.
Optionally, the second housing further comprises a carton as a support; and is also provided with
The outer metal wrapping layer wraps the outer portion of the carton.
Optionally, the outer metal wrapping layer is aluminum foil.
Optionally, the base station tooling assembly comprises a holding pole and a base station tooling piece fixed on the holding pole;
the base station tooling piece is made of aluminum alloy and is provided with a paint coating.
Optionally, the shielding shell is sized to: the length is more than or equal to 1316mm, the width is more than or equal to 1122mm, and the height is more than or equal to 1620mm.
According to another aspect of the embodiment of the invention, a calibration method for testing a 5G base station based on a reverberation room is further provided, wherein the calibration system of any one of the above is adopted to calibrate a target test item of a base station to be tested.
Optionally, the target test item includes at least one of:
Universal spurious testing;
testing the total radiation power in the band;
Additional spurious testing; and is also provided with
The target calibration result includes a path loss calibration average.
According to the calibration system and the method for the 5G base station test based on the reverberation chamber, the calibration substitute is adopted to replace the base station to be tested for calibration, and the calibration substitute is selected so that the difference value between the target calibration result obtained based on the calibration substitute and the target calibration result obtained based on the base station to be tested falls into the uncertainty requirement range of the 5G base station test based on the reverberation chamber under the same calibration condition, so that the actual 5G base station is not required to be used on the premise of meeting a certain measurement uncertainty, and the substitute material is used for carrying out advanced calibration and one-time calibration, and the problem that recalibration is required before each measurement for different base station equipment in the measurement of the 5G base station based on the reverberation chamber is solved. Especially in the stray test with more test frequency points and wider frequency range, the measuring time is greatly saved, and the equipment such as a high-frequency instrument signal source, a frequency spectrograph, a network analyzer and the like which are expensive is not required to be occupied for a long time, so that the test cost is also greatly reduced.
Furthermore, in the calibration system and method for 5G base station testing based on the reverberation chamber according to the embodiments of the present invention, a shell, a carton wrapped with an outer metal wrapping layer (such as aluminum foil) with a thickness not exceeding 1mm, or a base station tooling assembly in a state of not installing a base station, which are made of a relatively common and easily available polymer material (such as polypropylene or glass fiber reinforced polypropylene) with a dielectric constant smaller than 3.6, are used as calibration substitutes, so that the feasibility and feasibility of the calibration system and method are further enhanced.
The foregoing description is only an overview of the present invention, and is intended to be implemented in accordance with the teachings of the present invention in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present invention more readily apparent.
The above, as well as additional objectives, advantages, and features of the present invention will become apparent to those skilled in the art from the following detailed description of a specific embodiment of the present invention when read in conjunction with the accompanying drawings.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:
FIG. 1 shows a schematic diagram of a calibration system for a reverberation room based 5G base station test according to one embodiment of the invention;
FIG. 2 shows a schematic diagram of a base station tooling assembly as a calibration alternative according to an embodiment of the present invention;
FIG. 3 is a graph showing a comparison of path loss calibration results for universal spurious test calibration with base station A at the 1-23GHz band using different calibration alternatives in accordance with one embodiment of the present invention;
FIG. 4 is a graph showing a comparison of path loss calibration results for universal spurious test calibration with base station B at the 29-50GHz band using a different calibration alternative in accordance with another embodiment of the present invention;
fig. 5 shows a path loss calibration result comparison of a base station a with a different calibration substitute for a universal spurious test calibration at the 40-50GHz band in accordance with a further embodiment of the present invention.
Detailed Description
Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
At present, the OTA field mainly comprises a far field, a compact range, a reverberation room and the like in the standard at home and abroad for 5G base station equipment test suggestion. The reverberant chamber (Reverberation Chamber) is suitable for TRP (Total Radiated Power ) class test, and its basic principle is as follows: the reverberant room has a large shielded metal housing and has one or several mode agitators (Stirrer) to randomize the field. By operating the mode stirrer, the mode in which electromagnetic waves exist in the cavity can be changed, thereby changing the coupling mode of the antenna and the cavity. The enclosed cavity with total reflection has one transmitting antenna capable of radiating power to one angle, and the electromagnetic wave is reflected by the mode stirrer and the shielding wall to form electromagnetic field environment with homogeneous power strength. This particular area may be referred to as the working area where the test is performed as if it were a "dead space" test in a shielded dark room.
Under the action of the stirrer, the energy density, the phase, the polarization and the incoming wave direction of the electromagnetic field at any position in the reverberation room are randomly changed according to a certain statistical distribution rule, so that the test in the reverberation room can be regarded as a random process under the rule condition. The response of the device under test to the field during the test is the time-integrated average response over the period of the stirrer change. Therefore, in accordance with this principle, in the calibration of the reverberation chamber, the device under test needs to be placed in the reverberation chamber and should be performed under the same conditions as the placement position at the time of the test and using the same stirrer program. The calibration needs to be re-performed for each measurement of a different device.
In the OTA measurement environments such as compact field and far field, the tested equipment is not required to be placed in the field environment in the calibration process, multiple calibrations are not required to be carried out on different tested equipment, and under the condition that no special field environment is changed, such as temperature and humidity or when the characteristics of equipment directly participating in calibration in the field environment change, the field is not required to be frequently calibrated, and data of one calibration can be used for a long time. Because of the special testing principle, the tested equipment must be placed in the reverberation room, and the calibration and measurement result is finally obtained through multiple average by the randomized motion mode of the stirrer. This causes problems such as longer calibration time and longer occupation time of the calibration meter.
In response to the above problems, the inventor breaks through the existing concept and creatively thinks about replacing the actual base station equipment with replacement materials for calibration. The inventors innovatively considered that in OTA power and spurious tests of 5G base stations (e.g., 5G millimeter wave base stations), a certain measurement uncertainty is allowed, and therefore, although there is a definite difference in calibration with an actual base station using an alternative material, because of the measurement uncertainty, if the result of calibration with the alternative material does not affect the determination of whether the test result passes or not, and at the same time, satisfies the requirement of measurement uncertainty, calibration with the alternative material may be performed (hereinafter referred to as an alternative calibration method).
Furthermore, the inventor also finds that the material, volume and the like of the measured piece can influence the distribution and statistical properties of the electromagnetic waves in the reverberation room, so that the accuracy of a substitute calibration method can be ensured as much as possible by selecting substitutes of proper material, volume and other factors according to the structure and the size of the actual base station equipment to be measured, and further the accuracy of the base station test is ensured.
Based on the findings and principles described above, the embodiments of the present invention provide a calibration system for 5G base station testing based on a reverberation room.
Fig. 1 shows a schematic diagram of a calibration system 10 for a reverberation room based 5G base station test according to one embodiment of the invention. Referring to fig. 1, a calibration system 10 may generally include: a shielding enclosure 11, the shielding enclosure 11 defining an interior cavity of the reverberation chamber, the interior cavity including a working region 13 of the reverberation chamber; one or more mode stirrers 12 disposed in the internal cavity outside the working area 13 for changing the mode of the electromagnetic waves in the internal cavity; a calibration substitute 14 of the base station to be tested, disposed within the working area 13; a reference antenna 15 provided at one side of the calibration substitute 14 for transmitting a calibration signal at the time of calibration; a measurement antenna 16, disposed on the other side of the calibration substitute 14, for receiving the calibration signal; and a calibration device 17 connected to the reference antenna 15 and the measurement antenna 16, respectively, for performing calculation according to the signal transmitted by the reference antenna 15 and the signal received by the measurement antenna 16, so as to obtain a target calibration result.
It will be appreciated that the working area 13, i.e. the area within which the device under test can be placed, is provided with a calibration substitute 14 for the base station under test when the calibration system 10 is used for calibration; when the calibration system 10 is used for testing a base station (in this case, its function is a test system), the actual base station to be tested is set in the working area 13.
One or more mode agitators 12 refers to 1, 2, or more mode agitators 12. In practice there may be more than 1 stirrer. The mode stirrer 12 may take various forms, such as a moving metal plate, a turntable, etc.
The reference antenna 15 is capable of radiating power (signal) to an angle, and the measurement antenna 16 may be disposed on the power radiation path of the reference antenna 15, with the signal transmission path between the reference antenna 15 and the measurement antenna 16 shown in fig. 1 by a broken line therebetween.
In some embodiments, the calibration device 17 may be a vector network analyzer meeting the frequency band requirement, and two ports of the vector network analyzer are respectively connected to the reference antenna 15 and the measurement antenna 16. In other embodiments, the calibration device 17 may comprise a signal source and a spectrometer connected to meet the frequency band requirements, the signal source being connected to the reference antenna 15 and the spectrometer being connected to the measurement antenna 16.
In this embodiment, the calibration substitute 14 may be selected such that the difference between the target calibration result obtained based on the calibration substitute 14 and the target calibration result obtained based on the base station under test under the same calibration conditions falls within the uncertainty requirement range of the 5G base station test based on the reverberation chamber.
In the calibration system 10 for testing the 5G base station based on the reverberation chamber provided by the embodiment of the invention, the base station to be tested is replaced by the calibration substitute for calibration, and the calibration substitute 14 is selected so that the difference between the target calibration result obtained based on the calibration substitute 14 and the target calibration result obtained based on the base station to be tested falls within the uncertainty requirement range of the 5G base station based on the reverberation chamber under the same calibration condition, so that the actual 5G base station is not required on the premise of meeting a certain measurement uncertainty, and the substitute material is used for carrying out advanced calibration and one-time calibration on the reverberation chamber OTA measurement environment of the 5G base station, thereby solving the problem that recalibration is required before each measurement for different base station equipment. Especially in the stray test with more test frequency points and wider frequency range, the measuring time is greatly saved, and the equipment such as a high-frequency instrument signal source, a frequency spectrograph, a network analyzer and the like which are expensive is not required to be occupied for a long time, so that the test cost is also greatly reduced.
As mentioned above, the material, volume, etc. of the measured object affect the distribution and statistical properties of the electromagnetic wave in the reverberation room, so that the substitute for the proper material, volume, etc. should be selected according to the structure and size of the actual base station device to be measured.
The inventors have found that the outermost housing of an actual 5G base station device is typically a polymer material of a certain dielectric constant and may also be provided with metal parts (e.g. heat sinks, shields etc.). To ensure the effect of the alternative calibration, it is possible to choose alternatives as close to the base station housing structure as possible, based on these structural features of the 5G base station device.
In one aspect, it is contemplated that alternatives to the polymeric material proximate the base station housing may be selected. In some embodiments, the calibration substitute 14 may be selected as a first housing having external dimensions comparable to the base station under test and made of a material having a dielectric constant less than 3.6.
Through a large number of searches and verifications, certain materials such as weak polar or nonpolar polymer materials, paper and the like can be found to meet the requirement that the dielectric constant is smaller than 3.6. Accordingly, the first housing may be a housing made of a weakly polar or non-polar polymer material having a dielectric constant less than 3.6 having an external dimension comparable to the base station under test. The optional low polarity or non-polar polymeric material may include, for example, polycarbonate, polypropylene (PP), glass fiber reinforced Polypropylene (Glass Fiber Reinforced Polypropylene), polytetrafluoroethylene, high density polyethylene, glass fiber reinforced styrene, acrylonitrile-butadiene-styrene copolymer, and the like. Preferably, the first shell made of polypropylene or glass fiber reinforced polypropylene is chosen because polypropylene or glass fiber reinforced polypropylene is stable in properties, moderate in strength and inexpensive and readily available.
Alternatively, the first housing may also be a carton having external dimensions comparable to the base station under test. The paper box can adopt a common paper box for packaging, such as a paper box for express delivery and the like. The carton is cheap and easy to obtain, has certain strength, can keep a regular shape, and is very suitable for serving as a calibration substitute of a base station to be tested.
On the other hand, it is contemplated that alternatives to metal pieces on the housing of the base station may be selected. In other embodiments, the calibration substitute 14 may be selected as a second housing having external dimensions comparable to the base station under test and comprising an outer metal wrap having a thickness of no more than 1 mm. The metal material of the external metal coating layer is not particularly limited, and any metal can be selected.
Optionally, the outer metal wrapping layer may be aluminum foil. Aluminum foil is a common metal film, is cheap and easy to obtain, and is easy to process.
Further, since the thickness of the outer metal coating layer of the second housing is very thin (not more than 1 mm), in order to maintain the outer metal coating layer in a regular shape equivalent to the base station to be tested, the second housing may further include a supporter to support the outer metal coating layer. The support may be formed of any structural member having a regular shape comparable to the base station to be tested.
In an alternative embodiment, a carton having an external dimension corresponding to the base station to be tested may be selected as the support of the second casing, and the outer metal wrapping layer is wrapped on the outside of the carton, that is, the second casing is composed of the carton having the external dimension corresponding to the base station to be tested and the outer metal wrapping layer wrapped on the outside of the carton.
In a preferred embodiment, the second housing may be a carton having an external dimension comparable to the base station under test wrapped with aluminum foil.
It should be noted that, herein, reference to "corresponding to the base station to be measured" means that the difference from the corresponding external dimensions (i.e., length, width, and height) of the base station to be measured is within ±10%. For example, the first housing has an external dimension equivalent to the base station to be measured, and means that the ratio of the difference between the lengths of the first housing and the base station to be measured to the length of the base station to be measured, the ratio of the difference between the widths of the first housing and the base station to be measured to the width of the base station to be measured, and the ratio of the difference between the heights of the first housing and the base station to be measured to the height of the base station to be measured are all in the range of-10% to 10%.
In still other embodiments, the calibration substitute 14 may also be selected from a base station tooling assembly in an uninstalled base station state. Specifically, the base station tooling assembly is specially used for the 5G base station.
Specifically, the base station tooling assembly may include a pole 141 and a base station tooling 142 secured to pole 141 as shown in fig. 2. The base station equipment may be suspended and secured by base station tooling 142 during testing. Alternatively, the base station tooling piece 142 may be made of an aluminum alloy and have a paint coating.
Further, the base station tooling assembly may further include a base 143, and the pole 141 is vertically fixed to the base 143.
Of course, when the first casing or the second casing is selected as the calibration substitute 14, a base station tooling assembly may be disposed in the reverberation room to fix the first casing or the second casing for calibration.
In the calibration system 10 for 5G base station testing based on the reverberation chamber according to the embodiment of the present invention, a shell, a carton made of a relatively common and easily available polymer material (such as polypropylene or glass fiber reinforced polypropylene) with a dielectric constant less than 3.6, a carton wrapped with an outer metal wrapping layer (such as aluminum foil) with a thickness not exceeding 1mm, or a base station tooling assembly in a state of not installing a base station can be used as the calibration substitute 14, so that the feasibility and feasibility of the calibration system 10 and the method are further enhanced.
Since the volume and the like of the measured piece can influence the distribution and the statistical characteristics of the electromagnetic waves in the reverberation room, the smaller the volume occupied by the measured piece in the reverberation room is, the smaller the influence of the measured piece on the distribution and the statistical characteristics of the electromagnetic waves in the reverberation room is. In practical applications, the size of the 5G base station is usually fixed, and therefore, in order to achieve a better alternative calibration effect, the size of the shielding shell 11 of the reverberation chamber can be set to: the length is more than or equal to 1316mm, the width is more than or equal to 1122mm, and the height is more than or equal to 1620mm. Under the size of a reverberation room of at least 1316mm (length) x 1122mm (width) x 1620mm (height), the influence of the volume of a measured piece (calibration substitute or base station to be measured) on the distribution and statistical properties of electromagnetic waves in the reverberation room can be effectively reduced, and better substitute calibration effect and test effect are ensured.
Based on the same technical concept, the embodiment of the invention also provides a calibration method for testing a 5G base station based on a reverberation room, which adopts the calibration system 10 of any embodiment or the combination of embodiments to calibrate the target test item of the base station to be tested.
Optionally, the target test item may include at least one of a general spurious test (e.g., a general spurious test in the 1-23GHz, 29-50GHz band), an in-band total radiated power test (e.g., a 24.25-24.45GHz, 27.1-27.5GHz, 26.2-27.0GHz band total radiated power test), an additional spurious test (e.g., a 23.6-24GHz band additional spurious test), and the like.
The purpose of the calibration is to obtain a power transfer function from the reference antenna 15 to the measurement antenna 16. For calibration with a network analyzer, the definition of the power transfer function is as follows:
In the above equation, e mis,meas is the mismatch of the measurement antennas, e mis,ref is the mismatch of the reference antennas, and η ref is the radiation efficiency of the reference antennas. Mismatch can be derived from 1- | < s 11＞F＞N|2 where < > represents the average of the N modes of stirring samples, F represents the frequency point acquired by the network analyzer, and N represents the number of state modes of the stirrer. G ref represents the power transfer function of the reverberant chamber (obtained from NF samples). The average is calculated over all frequencies F and mode-stirring samples N. It is noted that the values of the measured antenna mismatch e mis,meas and the radiation efficiency η meas are not considered, since they are the same during calibration and EUT (Equipment Under Test, part under test) measurements and therefore do not affect the final result.
And obtaining a power transfer function from the reference antenna to the measurement antenna through calibration, and further obtaining a target calibration result through calculation. In particular, the target calibration result may comprise a path loss calibration average.
The calibration results obtained with the different calibration alternatives are examined below by way of example.
The alternative calibration method proposed by the invention is based on certain measurement uncertainty requirements. For example, in 5G millimeter wave OTA power and spurious measurements, the allowable uncertainty range in the standard is shown in table 1 below:
TABLE 1 uncertainty in 5G millimeter wave OTA Power and spurious measurements
Example 1
And respectively taking the 5G millimeter wave base station A, a base station tooling assembly (in a state of not installing the base station) and a carton as measured pieces, and calibrating the universal spurious test under the frequency band of 1-23GHz, wherein the obtained path loss calibration result is shown in figure 3.
As can be seen from fig. 3, the difference between the path loss calibration value obtained by using the base station tooling assembly and the carton as calibration substitutes and the path loss calibration value obtained by using the base station a for calibration is between 0.01 dB and 2.3dB, so as to meet the uncertainty requirement of the stray power test in table 1.
Example 2
Calibration of in-band TRP power tests was performed with 5G millimeter wave base station a, base station tooling assembly (in the state of no base station installed) and carton as test pieces, respectively, and the obtained path loss calibration results are shown in table 2 below.
Table 2 calibration contrast of TRP power different alternatives in base station a band
As can be seen from table 2, the difference between the path loss calibration average value obtained by using the base station tooling assembly and the carton as calibration substitutes and the path loss calibration average value obtained by using the base station a for calibration is between-0.42 dB and 0.38dB, so as to meet the uncertainty requirement of the in-band transmit power test in table 1.
Example 3
And respectively using the 5G millimeter wave base station A, a base station tooling assembly (in a state of not installing the base station) and the carton as measured pieces to calibrate the 23.6-24GHz frequency band extra spurious tests, wherein the obtained path loss calibration results are shown in the following table 3.
TABLE 3 calibration contrast of additional spurious bands 23.6-24GHz for base station A
As can be seen from table 3, the difference between the path loss calibration average value obtained by using the base station tooling assembly and the carton as calibration substitutes and the path loss calibration average value obtained by using the base station a for calibration is between 0.41 dB and 0.66dB, so as to meet the uncertainty requirement of the spurious test in table 1.
Example 4
And respectively taking the 5G millimeter wave base station A, a base station tooling assembly (in a state of not installing the base station) and a carton as measured pieces, and calibrating the universal spurious test under the frequency band of 29-50GHz, wherein the obtained path loss calibration result is shown in figure 4.
As can be seen from fig. 4, the difference between the path loss calibration value obtained by using the base station tooling assembly and the carton as calibration substitutes and the path loss calibration value obtained by using the base station a for calibration is between 0.03 dB and 1.3dB, so as to meet the uncertainty requirement of the stray power test in table 1.
Example 5
Calibration of in-band TRP power tests was performed with a first housing made of 5G millimeter wave base station B, glass fiber reinforced polypropylene as a test piece, respectively, and the obtained path loss calibration results are shown in table 4 below. The housing material of the base station B is PC (Polycarbonate).
Table 4 calibration contrast of TRP power different alternatives in base station B band
As can be seen from table 4, the difference between the path loss calibration average value obtained by using the first shell made of glass fiber reinforced polypropylene as the calibration substitute and the path loss calibration average value obtained by using the base station B for calibration is between-0.13 dB and 0.3dB, which can meet the uncertainty requirement of the in-band transmit power test in table 1.
Example 6
And respectively taking a 5G millimeter wave base station B and a first shell made of glass fiber reinforced polypropylene as a tested piece to calibrate an additional stray test in a 23.6-24GHz frequency band, wherein the obtained path loss calibration results are shown in the following table 5. The housing material of the base station B is PC.
TABLE 5 calibration contrast of additional spurious bands 23.6-24GHz for base station B
As can be seen from table 5, the difference between the path loss calibration average value obtained by using the first shell made of glass fiber reinforced polypropylene as the calibration substitute and the path loss calibration average value obtained by using the base station B for calibration is-0.35 dB, which can meet the uncertainty requirement of the stray power test in table 1.
Example 7
And respectively taking the 5G millimeter wave base station A, glass fiber reinforced polypropylene (namely glass fiber reinforced PP), the carton and the carton wrapped by aluminum foil as measured pieces, and carrying out calibration of a general stray test at a frequency band of 40-50GHz, wherein the obtained path loss calibration result is shown in figure 5.
As can be seen from fig. 5, the difference between the pathloss calibration values obtained with other calibration alternatives and the pathloss calibration values obtained with the calibration of base station a are all between 0.1-1dB, which can meet the uncertainty requirement of the stray power test in table 1.
The feasibility of using the surrogate material for calibration over a range of uncertainties can be demonstrated by comparison of typical surrogate materials in the above examples.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all technical features thereof can be replaced by others within the spirit and principle of the present invention; such modifications and substitutions do not depart from the scope of the invention.
Claims (9)
1. A calibration system for a 5G base station test based on a reverberation room, comprising:
A shielding enclosure defining an interior cavity of the reverberation chamber, the interior cavity including a working region of the reverberation chamber;
one or more mode stirrers disposed in the internal cavity outside the working area for changing the mode of electromagnetic waves in the internal cavity;
The calibration substitute of the base station to be tested is arranged in the working area;
a reference antenna provided at one side of the calibration substitute for transmitting a calibration signal at the time of calibration;
a measurement antenna disposed on the other side of the calibration substitute for receiving the calibration signal; and
The calibration device is respectively connected with the reference antenna and the measurement antenna and is used for calculating according to signals transmitted by the reference antenna and signals received by the measurement antenna to obtain a target calibration result, wherein the target calibration result comprises a path loss calibration average value;
the calibration substitute is selected so that the difference value between a target calibration result obtained based on the calibration substitute and a target calibration result obtained based on the base station to be tested falls within an uncertainty requirement range of a 5G base station test based on a reverberation room under the same calibration condition; and is also provided with
The calibration substitute is any one of the following:
a first housing having an external dimension comparable to the base station under test and made of a material having a dielectric constant less than 3.6;
a second housing having an external dimension comparable to the base station under test and comprising an external metal wrapping layer having a thickness of not more than 1 mm;
and a base station tooling assembly in a state of not installing the base station.
2. The calibration system of claim 1, wherein,
The first shell is made of a low-polarity or nonpolar polymer material with a dielectric constant less than 3.6; or (b)
The first housing is a carton.
3. The calibration system of claim 2, wherein,
The polymer material is polypropylene or glass fiber reinforced polypropylene.
4. The calibration system of claim 1, wherein,
The second housing further comprises a carton as a support; and is also provided with
The outer metal wrapping layer wraps the outer portion of the carton.
5. The calibration system of claim 1, wherein,
The outer metal wrapping layer is aluminum foil.
6. The calibration system of claim 1, wherein,
The base station tooling assembly comprises a holding pole and a base station tooling piece fixed on the holding pole;
the base station tooling piece is made of aluminum alloy and is provided with a paint coating.
7. The calibration system of claim 1, wherein,
The shield housing is sized to: the length is more than or equal to 1316mm, the width is more than or equal to 1122mm, and the height is more than or equal to 1620mm.
8. A method for calibrating a 5G base station test based on a reverberation room, characterized in that the calibration system according to any one of claims 1 to 7 is used for calibrating a target test item of a base station to be tested.
9. The method of calibrating according to claim 8, wherein,
The target test item includes at least one of:
Universal spurious testing;
testing the total radiation power in the band;
Additional spurious testing.
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| CN106330348A (en) * | 2016-08-18 | 2017-01-11 | 深圳天祥质量技术服务有限公司 | Method and device for testing stray radiant power of wireless product |
| CN106597340A (en) * | 2016-12-09 | 2017-04-26 | 北京无线电计量测试研究所 | Electromagnetic field sensor calibration system based on reverberation room and method thereof |
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| US8660812B2 (en) * | 2010-06-04 | 2014-02-25 | Apple Inc. | Methods for calibrating over-the-air path loss in over-the-air radio-frequency test systems |
| CN102857309B (en) * | 2012-07-27 | 2016-09-28 | 中兴通讯股份有限公司 | The method of testing of a kind of radio frequency index of active antenna system and device |
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| CN106330348A (en) * | 2016-08-18 | 2017-01-11 | 深圳天祥质量技术服务有限公司 | Method and device for testing stray radiant power of wireless product |
| CN106597340A (en) * | 2016-12-09 | 2017-04-26 | 北京无线电计量测试研究所 | Electromagnetic field sensor calibration system based on reverberation room and method thereof |
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