CN114884586B - Stirrer for reverberation room and reverberation room with same - Google Patents
Stirrer for reverberation room and reverberation room with same Download PDFInfo
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- CN114884586B CN114884586B CN202210351957.5A CN202210351957A CN114884586B CN 114884586 B CN114884586 B CN 114884586B CN 202210351957 A CN202210351957 A CN 202210351957A CN 114884586 B CN114884586 B CN 114884586B
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- 238000003756 stirring Methods 0.000 claims abstract description 17
- 230000008859 change Effects 0.000 claims abstract description 9
- 239000002184 metal Substances 0.000 claims description 10
- 230000005540 biological transmission Effects 0.000 claims description 9
- 230000000737 periodic effect Effects 0.000 claims description 3
- 230000004044 response Effects 0.000 abstract description 5
- 238000012360 testing method Methods 0.000 description 27
- 238000010586 diagram Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 230000005684 electric field Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000010907 mechanical stirring Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B17/00—Monitoring; Testing
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
Abstract
The present disclosure provides a stirrer for a reverberation chamber comprising a controller and at least one AFSS structure, wherein: the controller is used for generating a control signal; the AFSS structure comprises a plurality of units which are arranged periodically, the units are divided into a plurality of loading groups, the units in each loading group are connected in series through an on-off control device, and the on-off control device is used for changing the on-off state in response to a control signal so as to change the stirring state of the stirrer. The present disclosure also provides a reverberant room including the mixer.
Description
Technical Field
The invention relates to the field of electric wave reverberation chambers for communication tests, in particular to a stirrer for a reverberation chamber and the reverberation chamber with the stirrer.
Background
In wireless testing, the electric wave reverberant room (reverberant room for short) has its unique advantages: the use of a smaller input power enables a large field strength response in the cavity; the working frequency range is large, and the testing efficiency is high; low measurement cost, wide application, and the like. Reverberation chambers have been developed from electromagnetic shielding chambers to test the electrical performance of devices under test by operating the shielding cavity in an overmode state. The reverberation chamber is essentially a resonant cavity, and the field type structure of the reverberation chamber is continuously changed due to the existence of various stirring modes, so that the reverberation chamber is endowed with the capability of electromagnetic testing and wireless channel simulation. Thus, the stirring regime is the core content of the reverberant room. In the related art, a mechanically agitated reverberation chamber is the most widely studied and used reverberation chamber because of its well-agitated effect and stable field uniformity that is widely accepted. The source stirring reverberation chamber changes the electric field distribution in the cavity by changing the position or polarization direction of the antenna in the cavity, so that the statistically uniform state of the electric field is achieved. In addition, the frequency stirring reverberation chamber is also arranged, and the eigenvalues of different eigenvectors are changed by continuously changing the frequency of electromagnetic waves injected into the cavity in a smaller frequency band range, so that the superposed composite field is changed, and finally, the statistically uniform field distribution is formed.
Disclosure of Invention
The present disclosure describes a mixer for a reverberant room and a reverberant room having the same.
According to a first aspect of embodiments of the present disclosure, there is provided a stirrer for a reverberation chamber comprising a controller and at least one AFSS structure, wherein: the controller is used for generating a control signal; the AFSS structure comprises a plurality of units which are arranged periodically, the units are divided into a plurality of loading groups, the units in each loading group are connected in series through an on-off control device, and the on-off control device is used for changing the on-off state in response to a control signal so as to change the stirring state of the stirrer.
According to one embodiment of the stirrer, the unit of the AFSS structure is a metal patch, which is arranged on the dielectric plate; or the cells of the AFSS structure are metal slits.
According to one embodiment of the stirrer, the periodic distance of the unit is smaller than the wavelength corresponding to the operating frequency of the reverberation chamber.
According to one embodiment of the whisk, the on-off control means is selected from one of the following: PIN diode, MESM device, radio frequency switch.
According to one embodiment of the agitator, the units in each loading group are aligned either transversely or longitudinally.
According to one embodiment of the beater, an indicator light is also connected to each loading group for indicating the on-off state of the loading group.
According to one embodiment of the agitator, the controller controls each of the AFSS structures independently when the number of AFSS structures is greater than one.
According to a second aspect of embodiments of the present disclosure, there is provided a reverberation chamber comprising a stirrer as described above.
According to one embodiment of the reverberant room, the AFSS structure is arranged in a shielding cavity of the reverberant room, and the distance from the inner wall of the shielding cavity is larger than one quarter of a wavelength corresponding to the operating frequency of the reverberant room.
According to one embodiment of the reverberation chamber, the AFSS structure of the mixer is arranged in three mutually perpendicular planes.
Drawings
Fig. 1 illustrates a schematic diagram of a stirrer according to one embodiment of the present disclosure.
Fig. 2 illustrates a schematic diagram of a stirrer according to one embodiment of the present disclosure.
Fig. 3 illustrates a schematic diagram of a patch FSS in the related art.
Fig. 4 is a schematic diagram of a slit type FSS in the related art.
Fig. 5 illustrates a schematic diagram of a reverberation chamber according to one embodiment of the disclosure.
Fig. 6 illustrates a schematic diagram of a reverberation chamber according to one embodiment of the disclosure.
Detailed Description
Embodiments of the present disclosure are described below with reference to the accompanying drawings. It should be understood that the drawings are not necessarily to scale. The described embodiments are exemplary and are not intended to limit the disclosure, these features may be combined with or substituted for the features of the embodiments in the same or similar manner. As used in this disclosure and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.
The frequency selective surface (Frequency Selective Surfaces, FSS) refers to an array of a number of identical resonant cells periodically arranged in one or two dimensions, which essentially corresponds to a spatial filter capable of controlling the transmission and reflection of electromagnetic waves incident on the array. When the frequency of the incident wave is just within the working frequency band of the FSS, the FSS can show the reflective or transmissive filtering characteristic according to the different unit structures, and the electromagnetic wave outside the working frequency band can transmit the FSS or be reflected by the FSS. FSS is not itself capable of absorbing energy, but can filter frequencies. Its scattering properties for electromagnetic waves change with frequency. FSS can be divided into a band-stop type FSS and a band-pass type FSS according to structures, and the band-stop type FSS shows total reflection characteristics near the unit resonant frequency. The band-pass FSS exhibits a full transmission characteristic in the vicinity of the cell resonance frequency. The two types of FSS have complementary properties.
In the related art, FSS is mainly applied to frequency multiplexing of antennas, circuit analog absorbers, and various spatial filters. However, the electromagnetic characteristics such as the resonance frequency and bandwidth of the FSS cannot be changed. An active frequency selective surface (Active Frequency Selective Surfaces, AFSS) refers to adding active devices to the FSS to adjust the filter characteristics of the FSS by externally applied excitation. The AFSS enables dynamic adjustment of the frequency selective characteristics.
Based on the above findings, in order to overcome the problem of the related art that the mixing effect of the reverberation chamber is not ideal at low frequencies to some extent, the present disclosure provides a mixer for the reverberation chamber and a reverberation chamber having the same.
Embodiments of the first aspect of the present disclosure provide a stirrer for a reverberation chamber comprising a controller and at least one AFSS structure wherein: the controller is used for generating a control signal; the AFSS structure comprises a plurality of units which are arranged periodically, the units are divided into a plurality of loading groups, the units in each loading group are connected in series through an on-off control device, and the on-off control device is used for changing the on-off state in response to a control signal so as to change the stirring state of the stirrer.
The technical effects of the present disclosure are explained herein. Unlike the physical "uniform plane wave" states that other electromagnetic measurement techniques are to achieve, the reverberation chamber is to achieve a mathematically statistically isotropic and uniform test environment. The stirring mode is therefore the core content of the reverberation chamber. In the related art, stirring means include mechanical stirring, source stirring, and frequency stirring. The stirrer disclosed by the invention provides a novel stirring mode, adopts an AFSS structure, divides a plurality of units comprising the AFSS structure into a plurality of loading groups connected in series, changes the electromagnetic boundary inside the shielding cavity of the reverberation chamber through the change of the on-off state of each loading group, and enables various reflected waves to form a multipath reflection environment in the reverberation chamber, so that electromagnetic fields in the multipath reflection environment are superimposed in all directions, and are expressed as plane wave superposition in all directions in mathematical statistics, thereby realizing uniform stirring.
Referring to fig. 1, fig. 1 illustrates a specific embodiment of a stirrer, including a controller 100 and upper and lower 2 AFSS structures 200, wherein each AFSS structure 200 includes 28 units 201 arranged periodically, in this embodiment, the units 201 are square metal patches disposed on a dielectric plate (not shown in the drawing), the 28 units 201 are divided into 4 loading groups, each loading group includes 7 units 201, the units 201 in each loading group are connected in series through an on-off control device 202, and the on-off control device 202 is used for changing the on-off state in response to a control signal sent by the controller 100 to change the stirring state of the stirrer.
Referring to fig. 2, fig. 2 illustrates another embodiment of a stirrer, comprising a controller 100 and upper and lower 2 AFSS structures 200. The upper AFSS structure 200 in FIG. 2 includes 20 periodically arranged units 201, divided into 4 load groups, each load group including 5 units 201; the lower located AFSS structure 200 in FIG. 2 includes 15 periodically arranged units 201, divided into 3 load groups, each load group including 5 units 201. In this embodiment, the unit 201 constituting the AFSS structure 200 is a metal slit (square annular metal structure), and accordingly, the on-off control device 202 is provided in a space formed by the metal slit. It should be noted that, in fig. 2, the connection lines for serial connection are shown in two schematic manners, i.e., a dotted line and a solid line, and two different line types indicate that the corresponding connection lines are located at different spatial positions, which is understood to be provided to avoid a short circuit when the on-off control device 202 is in a connected state.
The two embodiments shown in fig. 1 and 2 are explained in more detail herein.
In the related art, FSS can be classified into two types according to cell shape and transmission characteristics: one type is a patch FSS, whose structure is schematically shown in fig. 3, in which when electromagnetic waves are irradiated, low-frequency electromagnetic waves oscillate and penetrate between capacitances formed between two patches, while high-frequency electromagnetic waves are reflected due to shorter wavelengths; one type is slit-type FSS, also called aperture-type FSS, and the schematic structure of which is shown in fig. 4, when electromagnetic waves are irradiated, high-frequency electromagnetic waves directly penetrate between slits due to shorter wavelengths, and low-frequency electromagnetic waves are reflected due to longer wavelengths.
For the embodiment shown in fig. 1, when the on-off control device 202 is in the off state, its AFSS structure is substantially equivalent to a patch FSS, i.e., low frequency transmission, high frequency reflection. When one or more on-off control devices 202 in the loading group are in a connected state, the capacitance formed between the units 201 of the loading group disappears due to conduction, at this time, the loading group is substantially equivalent to a slit FSS, and electromagnetic waves of high frequency and low frequency are reflected, that is, the whole frequency band presents reflection characteristics, so that the transmission characteristics of the AFSS structure are changed, the electromagnetic boundary inside the shielding cavity of the reverberation chamber is changed, and a better stirring effect can be obtained at the low frequency. In the related art, the lowest available frequency is an important index for evaluating the reverberation room, and determines the low frequency range of the electromagnetic test activity in the reverberation room.
For the embodiment shown in fig. 2, when the on-off control device 202 is in the off state, its AFSS structure is substantially equivalent to a slit-type FSS, i.e., high frequency transmission, low frequency reflection. When the on-off control devices 202 in one or more of the loading groups are in a connected state, the AFSS structure is still in a gap state, but the size of the gap is changed, the connected loading groups divide the original gap into smaller parts, so that at least part of the high-frequency bands which can be transmitted originally show reflection characteristics, the transmission characteristics of the AFSS structure are changed, the electromagnetic boundary inside the shielding cavity of the reverberation chamber is changed, and a better stirring effect can be obtained at a high frequency.
The stirrer of the present disclosure may include either or both of the above two embodiments.
Alternatively, referring to fig. 1-2, the periodic distance L of the unit 201 is less than the wavelength corresponding to the operating frequency of the reverberation chamber.
The illustrated embodiments of fig. 1 and 2 each include 2 AFSS structures 200, and controller 100 independently controls each of the 2 AFSS structures 200. The number of AFSS structures included with the agitators of the present disclosure is not limited thereto. In the embodiment illustrated in fig. 1 and 2, the on-off control device 202 is a diode, more specifically, may be a PIN diode, and in other embodiments, the on-off control device may be a MESM device or a radio frequency switch, and the on-off control device may change the on-off state by using a direct current or alternating current signal.
Alternatively, the units in each loading group are arranged in a straight line in the lateral or longitudinal direction, and the arrangement of the units in the present disclosure is not limited thereto, but may be arranged in a zigzag line, or in a curved line, or the like. It will be appreciated that referring to fig. 2 and 5, when the number of AFSS structures 200 is greater than 1, the number of units 201, the number of loading groups, and the arrangement of units 201 in each AFSS structure 200 may be different.
Optionally, an indicator light, for example, a light emitting diode, may be connected in series to each loading group, for indicating the on-off state of the loading group. The method is beneficial to intuitively knowing the working state of the loading group and finding out the fault condition in time.
Another embodiment of the present disclosure provides a reverberant room including the aforementioned stirrer. Referring to fig. 5-6, in some embodiments, the reverberation chamber includes a shielded cavity 900, a device under test mounting stage 300 disposed inside the shielded cavity 900, a test antenna 400, a baffle 500 (for preventing direct coupling of the test antenna 400 to the device under test), a test meter 600 (not shown in fig. 5) disposed outside the shielded cavity 900, a controller 100 (not shown in fig. 5), and a host computer 700 (not shown in fig. 5). The test instrument 600 is connected to the test antenna 400, and the test instrument 600 is one or more of a vector network analyzer, a comprehensive tester, and a spectrometer, for example. The test meter 600 may also be connected to the device under test according to the test requirements; the controller 100 is coupled to 2 AFSS structures, and in some embodiments the device under test mount 300 is a turntable, and the controller 100 may also be coupled to the device under test mount 300 for changing the position of the device under test during testing, as desired. The upper computer 700 is connected to the controller 100 and the test meter 600, and is used for sending instructions to the controller 100 and the test meter 600 and obtaining test data of the test meter 600.
In the embodiment illustrated in fig. 5-6, the AFSS structure of the mixer of the reverberation chamber is arranged in 2 mutually perpendicular planes. Alternatively, in other embodiments, the AFSS structure of the agitator is disposed on 1 plane. Alternatively, in other embodiments, the AFSS structure of the stirrer is disposed in 3 mutually perpendicular planes.
Alternatively, referring to fig. 6, the distance D of the whisk's AFSS structure 200 from the inner wall of the shielded enclosure 900 is greater than one quarter of a wavelength corresponding to the operating frequency of the reverberant chamber.
It should be noted that, the drawings in the present disclosure are simplified schematic diagrams, and are only used to schematically illustrate the positional relationship and the connection relationship between the parts in the embodiments.
In the above description, descriptions of the terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one implementation or example of the present disclosure. In the present disclosure, the schematic representations of the above terms are not necessarily for the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present disclosure, the meaning of "a plurality" is at least two, such as two, three, etc., unless explicitly specified otherwise.
Although embodiments of the present disclosure have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the present disclosure, and that variations, modifications, alternatives, and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the present disclosure.
Claims (9)
1. A mixer for a reverberation chamber comprising a controller and at least one AFSS structure wherein:
The controller is used for generating a control signal;
The AFSS structure comprises a plurality of units which are arranged periodically, the units are divided into a plurality of loading groups, the units in each loading group are connected in series through an on-off control device, and the on-off control device is used for responding to the control signal to change the on-off state so as to change the stirring state of the stirrer;
The unit of the AFSS structure is a metal patch and is arranged on a dielectric plate; or the units of the AFSS structure are metal gaps;
when the unit of the AFSS structure is a metal patch, when the on-off control device is in an off state, the AFSS structure is equivalent to a patch type FSS, namely low-frequency transmission and high-frequency reflection, when one or more on-off control devices in the loading group are in an on state, the capacitance formed between the units of the loading group disappears due to conduction, at the moment, the loading group is equivalent to a slit type FSS, and at the moment, electromagnetic waves with high frequency and low frequency are reflected, namely the whole frequency band shows reflection characteristics;
When the unit of the AFSS structure is a metal gap, the AFSS structure is equivalent to gap FSS, namely high-frequency transmission and low-frequency reflection when the on-off control device is in an off state, and the AFSS structure is still in a gap type when one or more on-off control devices in the loading groups are in a connected state, but the size of the gap is changed, and the connected loading groups divide the original gap into smaller parts, so that at least part of high-frequency bands which can be transmitted originally show reflection characteristics.
2. The mixer of claim 1 wherein the periodic distance of the unit is less than a wavelength corresponding to the operating frequency of the reverberation chamber.
3. The mixer of claim 1 wherein said on-off control means is selected from one of the following: PIN diode, MESM device, radio frequency switch.
4. The beater of claim 1, wherein the units in each of the loading groups are aligned transversely or longitudinally.
5. The mixer of claim 1 wherein an indicator light is also connected to each of said loading groups for indicating the on-off status of said loading groups.
6. The mixer of claim 1 wherein said controller independently controls each of said AFSS structures when the number of said AFSS structures is greater than one.
7. Reverberant chamber, characterized in that it comprises a stirrer according to any one of claims 1 to 6.
8. The reverberant compartment of claim 7, wherein the AFSS structure is provided within a shielded cavity of the reverberant compartment, a distance from an inner wall of the shielded cavity being greater than one quarter of a wavelength corresponding to an operating frequency of the reverberant compartment.
9. The reverberant compartment of claim 7, wherein the AFSS structures of the agitators are disposed in three mutually perpendicular planes.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210351957.5A CN114884586B (en) | 2022-04-02 | 2022-04-02 | Stirrer for reverberation room and reverberation room with same |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210351957.5A CN114884586B (en) | 2022-04-02 | 2022-04-02 | Stirrer for reverberation room and reverberation room with same |
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| CN114884586B true CN114884586B (en) | 2024-04-30 |
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103502824A (en) * | 2011-01-18 | 2014-01-08 | 香港大学 | Compact electronic reverberation chamber |
| CN104133126A (en) * | 2014-07-01 | 2014-11-05 | 陕西海泰电子有限责任公司 | Source stirring electromagnetic reverberation chamber and stirring method thereof |
| CN106329041A (en) * | 2016-09-26 | 2017-01-11 | 南京航空航天大学 | Multifunctional active frequency selective surface and control method thereof |
| CN112881825A (en) * | 2021-01-11 | 2021-06-01 | 西安交通大学 | Reverberation room test system with temperature control system and test method |
| CN113295941A (en) * | 2021-04-25 | 2021-08-24 | 中国人民解放军陆军工程大学 | Method for testing environmental electromagnetic radiation sensitivity of reverberation room based on interference probability |
| CN113625068A (en) * | 2020-05-06 | 2021-11-09 | 上海沃尔沃汽车研发有限公司 | Electromagnetic compatibility testing chamber for motor vehicle |
| WO2022033770A1 (en) * | 2020-08-14 | 2022-02-17 | Bluetest Ab | A high-frequency mode stirrer for reverberation chambers |
-
2022
- 2022-04-02 CN CN202210351957.5A patent/CN114884586B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103502824A (en) * | 2011-01-18 | 2014-01-08 | 香港大学 | Compact electronic reverberation chamber |
| CN104133126A (en) * | 2014-07-01 | 2014-11-05 | 陕西海泰电子有限责任公司 | Source stirring electromagnetic reverberation chamber and stirring method thereof |
| CN106329041A (en) * | 2016-09-26 | 2017-01-11 | 南京航空航天大学 | Multifunctional active frequency selective surface and control method thereof |
| CN113625068A (en) * | 2020-05-06 | 2021-11-09 | 上海沃尔沃汽车研发有限公司 | Electromagnetic compatibility testing chamber for motor vehicle |
| WO2022033770A1 (en) * | 2020-08-14 | 2022-02-17 | Bluetest Ab | A high-frequency mode stirrer for reverberation chambers |
| CN112881825A (en) * | 2021-01-11 | 2021-06-01 | 西安交通大学 | Reverberation room test system with temperature control system and test method |
| CN113295941A (en) * | 2021-04-25 | 2021-08-24 | 中国人民解放军陆军工程大学 | Method for testing environmental electromagnetic radiation sensitivity of reverberation room based on interference probability |
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