Bluetooth radio frequency test method and device

Abstract

The invention discloses a Bluetooth radio frequency test method and device, and the method comprises the steps: obtaining a first size of a Bluetooth module antenna and a second size of a coupling plate antenna, and obtaining a first induction near-field region and a first radiation near-field region of the Bluetooth module antenna through calculation according to the first size and a wavelength; calculating a second induction near-field region and a second radiation near-field region of the coupling plate antenna according to the second size and the wavelength; the first distance between the Bluetooth module antenna and the coupling plate antenna is obtained, the first distance is adjusted, the first distance is at least in the first radiation near field area, the Bluetooth module antenna and the coupling plate antenna work normally, coupling is avoided, and stability and consistency of test data are improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of radio frequency testing, and in particular to a method and device for testing a Bluetooth radio frequency. Background Art

[0002] With the rapid development of electronic technology, Bluetooth devices are widely used in various smart products. After the Bluetooth devices are completed on the production line, they enter the testing phase. It is necessary to test the performance of the Bluetooth devices and detect the stability of the performance. However, due to different testing environments and equipment, there are many changing factors, and the test results are unstable and the consistency of the test data is poor, resulting in uneven test data of the three channels of the product, low, medium and high, a decrease in product yield, rework and multiple tests, a waste of working hours and labor costs, and low factory production efficiency. It is necessary to find the factors that affect the stability of the test data among many changing factors. Therefore, a Bluetooth radio frequency testing method and device are needed to make the Bluetooth radio frequency test data stable and consistent, and solve the problem of low product yield in the factory. This is a problem that needs to be solved in the relevant technical field. Summary of the invention

[0003] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0004] The embodiments of the present invention provide a Bluetooth radio frequency testing method and device, which can effectively improve the stability and consistency of Bluetooth radio frequency test data, solve the problem of low yield of factory products, improve production line efficiency, and save man-hours and labor costs.

[0005] In the first aspect, an embodiment of the present invention provides a Bluetooth radio frequency testing method, the method comprising: obtaining the working frequency of the antenna, and calculating the wavelength of the antenna electromagnetic wave according to the working frequency; obtaining the first size of the Bluetooth module antenna and the second size of the coupling plate antenna, and calculating the first inductive near field area and the first radiative near field area of ​​the Bluetooth module antenna according to the first size and the wavelength; calculating the second inductive near field area and the second radiative near field area of ​​the coupling plate antenna according to the second size and the wavelength; obtaining the first distance between the Bluetooth module antenna and the coupling plate antenna, and adjusting the first distance so that the first distance is at least within the range of the first radiative near field area. It can be seen from the above method that when testing Bluetooth radio frequency, there are unstable and inconsistent test data, so it is necessary to improve the test method of the Bluetooth module. In this embodiment, by setting the distance between the Bluetooth module antenna and the coupling plate antenna, the two antennas are within a suitable working range, avoiding the coupling effect between the Bluetooth module antenna and the coupling plate antenna to interfere with each other, resulting in unstable test data. Therefore, within the effective test range, the Bluetooth module antenna and the coupling plate antenna can work normally to ensure stable test data.

[0006] In a specific feasible implementation scheme, the first distance is adjusted so that the first distance is within the range of the first radiation near field zone and the second radiation near field zone at the same time. When the distance between the Bluetooth module antenna and the coupling plate antenna is too close, coupling will occur and cause interference, making the test data unstable. Adjusting the distance between the two antennas so that it is within a suitable range can avoid coupling between the Bluetooth module antenna and the coupling plate antenna. At the same time, the test data is stable and consistent. When the distance between the Bluetooth module antenna and the coupling plate antenna is further increased to a certain range, the test data does not continue to improve, but deteriorates. Because the distance is too large, the coupling plate needs to increase the line loss compensation. When the line loss compensation increases, the data of the Bluetooth RF test will be unstable. Therefore, in this embodiment, when the distance between the Bluetooth module antenna and the coupling plate antenna is within the range of the first radiation near field zone and the second radiation near field zone at the same time, there is no energy radiated outward between the two antennas, and the antenna enters a better working state.

[0007] In a specific implementation, the working frequency of the Bluetooth module antenna is 2.45 GHz. Bluetooth technology generally uses the 2.4 GHz ISM band, 2400 to 2483.5 MHz. In this embodiment, the working frequency of the Bluetooth module antenna is 2.45 GHz.

[0008] In a specific implementation method, the first dimension is designed to be a quarter of the wavelength, and the second dimension is designed to be a half of the wavelength. In this embodiment, the coupling plate is designed as a dipole antenna, that is, the antenna length is half of the working wavelength.

[0009] In a specific embodiment, the wavelength calculation formula is: Where λ is the working wavelength of the antenna, f is the working frequency of the antenna, μ r is the relative magnetic permeability, ε r is the relative dielectric constant, ν 0 is the speed of light in a vacuum.

[0010] In a specific embodiment, the sensing near field region is The radiation near field region is where r 1 is the distance of the antenna sensing near field, r 2 is the distance of the antenna radiation near field, D is the maximum geometric size of the antenna, and λ is the operating wavelength of the antenna.

[0011] In the second aspect, an embodiment of the present invention provides a Bluetooth radio frequency test device, including a radio frequency test system, a test device, a coupling plate and a fixture. The radio frequency test system is configured with an application for controlling the test device to perform Bluetooth radio frequency testing. A fixture for accommodating a Bluetooth module is provided on the coupling plate. The test device transmits data with the Bluetooth module through the coupling plate. The fixture makes the distance between the Bluetooth module to be tested and the coupling plate at least within the radiation near field of the Bluetooth module. The distance between the Bluetooth module to be tested and the coupling plate is adjusted by the fixture, so that the distance between the antenna of the Bluetooth module and the antenna of the coupling plate is at least within the radiation near field of the Bluetooth module, so as to avoid the coupling effect caused by the distance between the antenna of the Bluetooth module and the antenna of the coupling plate being too close to each other, resulting in interference and making the test data unstable.

[0012] In a specific possible implementation scheme, the fixture makes the distance between the Bluetooth module to be tested and the coupling plate be within the radiation near field range of the Bluetooth module and the coupling plate antenna at the same time.

[0013] In a specific implementation scheme, the test equipment includes a Bluetooth test machine, a Bluetooth channel switch matrix and a shielding box. The Bluetooth test machine is connected to the RF test system through a GPI B-USB card. The coupling board is arranged in the shielding box, and the coupling board is connected to the Bluetooth test machine through the Bluetooth channel switch matrix.

[0014] In a specific implementation, the fixture is provided with a groove for accommodating the Bluetooth module, and the groove matches the outer contour of the Bluetooth module. The groove on the fixture can accommodate the Bluetooth module, so that the placement position of the Bluetooth module is more accurate when testing the Bluetooth module, and the antenna distance between the Bluetooth module and the coupling plate can be precisely controlled.

[0015] The embodiment of the present invention includes: obtaining the working frequency of the antenna, and calculating the wavelength of the electromagnetic wave of the antenna according to the working frequency; obtaining the first size of the Bluetooth module antenna and the second size of the coupling plate antenna, and calculating the first inductive near field area and the first radiative near field area of ​​the Bluetooth module antenna according to the first size and the wavelength; calculating the second inductive near field area and the second radiative near field area of ​​the coupling plate antenna according to the second size and the wavelength; obtaining the first distance between the Bluetooth module antenna and the coupling plate antenna, and adjusting the first distance so that the first distance is at least within the range of the first radiative near field area. This embodiment sets the distance between the Bluetooth module antenna and the coupling plate antenna so that the distance between the two antennas is within a suitable working range, thereby avoiding the coupling effect between the Bluetooth module antenna and the coupling plate antenna, which interferes with each other and causes unstable test data. Therefore, within the effective test range, the Bluetooth module antenna and the coupling plate antenna can work normally, ensuring stable test data.

[0016] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0018] Figure 1 It is a main flow chart of a Bluetooth radio frequency testing method provided by one embodiment of the present invention;

[0019] Figure 2 It is a statistical diagram of the distance between the Bluetooth headset and the coupling plate and the test yield rate provided by an embodiment of the present invention;

[0020] Figure 3 1 is a schematic diagram of CPK distribution when the distance between the Bluetooth headset and the coupling plate is 6 mm according to an embodiment of the present invention;

[0021] Figure 4 1 is a schematic diagram of CPK distribution when the distance between the Bluetooth headset and the coupling plate is 10 mm according to an embodiment of the present invention;

[0022] Figure 5 1 is a schematic diagram of CPK distribution when the distance between the Bluetooth headset and the coupling plate is 15 mm according to an embodiment of the present invention;

[0023] Figure 6 is a statistical diagram of the distance between a Bluetooth headset and a coupling plate and a test yield rate provided by another embodiment of the present invention;

[0024] Figure 7 It is a schematic diagram of a Bluetooth radio frequency testing device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] It should be understood that in the description of the embodiments of the present invention, at least one (or one) means one and more than one, including one, greater than, less than, exceeding, etc. are understood to exclude the number itself, and above, below, within, etc. are understood to include the number itself. If there is a description of "first", "second", etc., it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features. "Smaller value", "larger value", etc. are the values ​​obtained after comparing two data.

[0027] As Bluetooth devices are widely used in various smart devices, Bluetooth devices need to continuously improve production efficiency and yield rate. After the Bluetooth devices are completed on the production line, they enter the testing phase. It is necessary to test the performance of the Bluetooth devices and detect the stability of the performance. However, due to different test environments and test equipment, there are unstable test results and poor consistency of test data, which leads to uneven test data of the three channels of low, medium and high products, reduced product yield, rework and multiple tests, waste of working hours and labor costs, and reduce factory production efficiency. Therefore, it is necessary to improve the test method and device of Bluetooth radio frequency so that the test data of Bluetooth radio frequency is stable and consistent, and solve the problem of low yield rate of factory products. To solve the above problems, after analyzing and verifying a large amount of test data, it is found that the distance between the Bluetooth module antenna and the coupling plate antenna plays a key role. When the distance between the Bluetooth module antenna and the coupling plate antenna is too close or too far, the Bluetooth module antenna and the coupling plate antenna produce coupling and interfere with each other, resulting in unstable test data. Therefore, when the distance between the Bluetooth module antenna and the coupling plate antenna is adjusted within a suitable range, the coupling effect between the Bluetooth module antenna and the coupling plate antenna can be avoided, so that the Bluetooth module antenna and the coupling plate antenna can work normally and ensure the stability of test data.

[0028] In a first aspect, an embodiment of the present invention provides a Bluetooth radio frequency testing method, the method comprising: obtaining an operating frequency of the antenna, and calculating a wavelength of an electromagnetic wave of the antenna according to the operating frequency; obtaining a first size of the Bluetooth module antenna and a second size of the coupling plate antenna, and calculating a first inductive near-field zone and a first radiative near-field zone of the Bluetooth module antenna according to the first size and the wavelength; calculating a second inductive near-field zone and a second radiative near-field zone of the coupling plate antenna according to the second size and the wavelength; obtaining a first distance between the Bluetooth module antenna and the coupling plate antenna, and adjusting the first distance so that the first distance is at least within the range of the first radiative near-field zone.

[0029] like Figure 1 As shown, Figure 1 An embodiment of the present invention provides a Bluetooth radio frequency testing method, which includes but is not limited to the following steps:

[0030] Step S100, obtaining the working frequency of the antenna, and calculating the wavelength of the antenna electromagnetic wave according to the working frequency;

[0031] Step S200, obtaining a first size of the Bluetooth module antenna and a second size of the coupling plate antenna, and calculating a first inductive near-field region and a first radiative near-field region of the Bluetooth module antenna according to the first size and the wavelength; and calculating a second inductive near-field region and a second radiative near-field region of the coupling plate antenna according to the second size and the wavelength;

[0032] Step S300, obtaining a first distance between the Bluetooth module antenna and the coupling plate antenna, and adjusting the first distance so that the first distance is at least within a first radiation near field region.

[0033] It can be seen from the above method that when the distance between the Bluetooth module antenna and the coupling plate antenna is too close, the Bluetooth module antenna and the coupling plate antenna produce coupling and interfere with each other, resulting in unstable test data. Therefore, it is necessary to set the distance between the Bluetooth module antenna and the coupling plate antenna within an appropriate range. After analysis and statistics of the test data, when the distance between the Bluetooth module antenna and the coupling plate antenna at least falls within the inductive near-field range of the Bluetooth module antenna, the Bluetooth module antenna and the coupling plate antenna will produce coupling and interfere with each other. Therefore, in this embodiment, it is necessary to obtain the inductive near-field range of the Bluetooth module antenna and the coupling plate antenna.

[0034] Specifically, first obtain the working frequency of the antenna, and determine the working frequency according to the frequency of the electromagnetic wave emitted by the antenna. In this embodiment, the Bluetooth module antenna complies with the regulations of the Bluetooth Technology Alliance (SIG), and the working frequency is 2.45 GHz. The wavelength of the electromagnetic wave of the antenna is obtained by calculation; further, the first size of the Bluetooth module antenna and the second size of the coupling plate antenna are obtained. The sizes of the Bluetooth module antenna and the coupling plate antenna can be designed in different sizes according to different specific usage scenarios. The first inductive near-field area and the first radiative near-field area of ​​the Bluetooth module antenna are calculated according to the first size of the Bluetooth module antenna and the wavelength of the electromagnetic wave of the antenna; the second inductive near-field area and the second radiative near-field area of ​​the coupling plate antenna are calculated according to the second size of the coupling plate antenna and the wavelength of the electromagnetic wave of the antenna; further, the first distance between the Bluetooth module antenna and the coupling plate antenna is obtained, and the first distance is adjusted so that the first distance is at least within the range of the first radiative near-field area. It can be understood that since the sizes of the antenna of the Bluetooth module and the antenna of the coupling plate are different, the ranges of their inductive near-field areas are also different. As long as the first distance does not fall into the inductive near-field area of ​​the Bluetooth module antenna, the coupling between the two antennas can be avoided.

[0035] In another specific implementation scheme, the first distance is adjusted so that the first distance is within the range of the first radiation near field zone and the second radiation near field zone at the same time. As mentioned above, when the distance between the Bluetooth module antenna and the coupling plate antenna is too close, coupling will occur and cause interference, making the test data unstable. Adjusting the distance between the two antennas so that it is within a suitable range can avoid coupling between the Bluetooth module antenna and the coupling plate antenna. At the same time, the test data is stable and consistent. When the distance between the Bluetooth module antenna and the coupling plate antenna continues to increase to a certain range, the test data does not continue to improve, but deteriorates. Because the distance is too large, the coupling plate needs to increase the line loss compensation. When the line loss compensation increases, the data of the Bluetooth RF test will be unstable. Therefore, the first distance between the Bluetooth module antenna and the coupling plate antenna needs to be within the range of the first radiation near field zone and the second radiation near field zone at the same time. At this time, there is no energy leakage and radiation between the two antennas, and the antenna enters a better working state.

[0036] In a specific implementation, the working frequency of the Bluetooth module antenna is 2.45 GHz. Bluetooth technology generally uses the 2.4 GHz ISM band, 2400 to 2483.5 MHz. In this embodiment, the working frequency of the Bluetooth module antenna is 2.45 GHz.

[0037] In another specific implementation scheme, the first size is designed to be one quarter of the wavelength, and the second size is designed to be one half of the wavelength. In this embodiment, the coupling plate is designed as a dipole antenna, that is, the antenna length is one half of the working wavelength. Of course, the antenna size can be set according to the specific application scenario.

[0038] In a specific embodiment, the wavelength calculation formula is: Where λ is the working wavelength of the antenna, f is the working frequency of the antenna, μ r is the relative magnetic permeability, ε r is the relative dielectric constant, ν 0 is the speed of light in vacuum. The inductive near field is The radiation near field region is where r 1 is the distance of the antenna sensing near field, r 2 is the distance of the antenna radiation near field, D is the maximum geometric size of the antenna, and λ is the operating wavelength of the antenna.

[0039] The method of the present invention is further described below in conjunction with examples. The following examples are illustrative rather than restrictive, and the protection scope of the present invention cannot be limited by the following examples.

[0040] In this embodiment, a TWS Bluetooth headset is taken as an example. Due to structural and space limitations, the geometric dimensions of the antenna routing of existing TWS Bluetooth headsets are generally less than a quarter of the working wavelength. In this embodiment, the working frequency of the Bluetooth module antenna is 2.45GHz. When f=2.45GHz, substitute the formula λ=ν / f to get λ=122.45mm, and a quarter of the working wavelength is 122.45mm / 4=30.6mm.

[0041] In this embodiment, the TWS Bluetooth headset antenna is designed to be 28 mm long. According to the induction near-field formula = 0.62√(D^3 / λ) and the radiation near-field formula = 2D^2 / λ, it can be seen that the induction near-field area of ​​the TWS Bluetooth headset antenna is within 8.30 mm, and the radiation near-field area of ​​the TWS Bluetooth headset antenna is in the range of 8.30 mm to 12.81 mm. The area greater than 12.81 mm is the radiation far-field area of ​​the TWS Bluetooth headset antenna.

[0042] The antenna of the coupling plate is designed as a dipole antenna, and its length is generally calculated as half of the working wavelength, that is, D = 61.25mm. According to the inductive near-field formula = 0.62√(D^3 / λ) and the radiation near-field formula = 2D^2 / λ, it can be seen that the inductive near-field area of ​​the coupling plate antenna is within 26.84mm, and the radiation near-field area of ​​the coupling plate antenna is between 26.84mm and 61.22mm. The area greater than 61.22mm is the radiation far-field area of ​​the coupling plate antenna.

[0043] Therefore, the wavelength of the electromagnetic wave is λ=122.45 mm, the first dimension is 28 mm, the second dimension is 61.25 mm, the first inductive near field zone is <8.30 ​​mm, the first radiative near field zone is 8.30 mm to 12.81 mm, the second inductive near field zone is <26.84 mm, and the second radiative near field zone is 26.84 mm to 61.22 mm.

[0044] According to the above calculated values, the first distance between the Bluetooth module antenna and the coupling plate antenna needs to be at least within the first radiation near field range, that is, within 8.30 mm to 12.81 mm.

[0045] like Figure 2 As shown, Figure 2 It is a statistical chart of the distance between the TWS Bluetooth headset and the coupling board and the test yield. Figure 2 The Bluetooth headset antenna is designed to be 28mm, and the coupling plate antenna is designed to be 61.25mm.

[0046] Figure 2The test data of the distance between TWS Bluetooth headsets and the coupling plate were divided into 3mm, 6mm, 8.3mm, 10mm, 12.81mm, 15mm, 20mm, 26.84mm and 30mm. The number of 2000 TWS Bluetooth headsets was counted in each test, and then the yield was calculated.

[0047] As calculated above, the sensing near field area of ​​the TWS Bluetooth headset antenna is within 8.30mm. Figure 2 When the distance between the TWS Bluetooth headset and the coupling plate is 3mm and 6mm, there are 59 and 33 defective TWS Bluetooth headsets, and the yield is 97.05% and 98.35% respectively. This shows that the TWS Bluetooth headset test is unstable and has poor consistency, which will increase the finished products of secondary testing, tertiary testing, and disassembly and repair. For factory production standards, a yield rate of less than 99% is unacceptable, and improvements must be made to increase the yield of TWS Bluetooth headsets to more than 99%.

[0048] As the distance between the TWS Bluetooth headset and the coupling plate increases, Figure 2 The test distance is 8.3mm, 10mm and 12.81mm. The radiation near field area of ​​the TWS Bluetooth headset antenna is between 8.30mm and 12.81mm. Therefore, the test distance falls within the radiation near field area of ​​the Bluetooth headset antenna. When the distance between the TWS Bluetooth headset and the coupling plate is 8.3mm, 10mm and 12.81mm respectively, the number of defective TWS Bluetooth headsets is significantly reduced, and the number of defective TWS Bluetooth headsets is within 15, which are 15, 9 and 13 respectively. The yield rate reaches 99.25%, 99.55% and 99.35% respectively. The yield rate shows that the consistency of the TWS Bluetooth headset is good, the product testing is stable, and it is conducive to reducing the factory's secondary testing, tertiary testing and disassembly repair of finished products. It can be determined that when the test distance is at least within the radiation near field area of ​​the Bluetooth headset antenna, the test data is stable and the consistency is good.

[0049] When the distance between the TWS headset and the coupling plate is further increased, the yield of the TWS Bluetooth headset does not increase further, but tends to decrease. Moreover, the greater the distance between the TWS Bluetooth headset and the coupling plate, the lower the yield of the TWS Bluetooth headset. In particular, when the distance between the TWS headset and the coupling plate is greater than 15mm, the yield of the TWS headset decreases more significantly. When the distance between the TWS headset and the coupling plate is 15mm, 20mm, 26.84mm and 30mm respectively, the distance falls into the far field of radiation of the Bluetooth headset antenna, and the yield of the TWS Bluetooth headset is 98.80%, 97.45%, 95.10% and 91.70% respectively, and the yield gradually decreases. Obviously, this yield is unacceptable.

[0050] It can be determined from the above statistical data that when the first distance between the Bluetooth headset and the coupling plate is at least within the first radiation near-field region, the test data of the Bluetooth module is stable and has good consistency.

[0051] Figures 3 to 5 The CPK distribution (Complete Process Capability Index) of the power of the TWS Bluetooth headset in the RF test equipment was counted when the distance between the TWS Bluetooth headset and the coupling plate was 6mm, 10mm and 15mm.

[0052] like Figure 3 As shown, Figure 3 The figure below shows the CPK distribution of the power of the TWS Bluetooth headset in the RF test equipment when the distance between the TWS Bluetooth headset and the coupling plate is 6mm. In the whole RF test equipment, the power index range of the TWS Bluetooth headset is -3dBm to 3dBm, the number of test samples is 2954, and its CPK index is 1.12. When the CPK index is less than 1.33, it indicates that the production process is not ideal and the production equipment is unstable, and improvements are needed to improve the production process capability and the stability of the production equipment.

[0053] like Figure 4 As shown, Figure 4 The figure below shows the CPK distribution of the power of the TWS Bluetooth headset in the RF test equipment when the distance between the TWS Bluetooth headset and the coupling plate is 10mm. In the whole machine RF test equipment, the power index range of the TWS Bluetooth headset is -3dBm to 3dBm, the number of test samples is 2954, and its CPK index is 1.37. When the CPK index is greater than 1.33, it is generally believed that the process is ideal and the production equipment is stable, and no improvement is needed. At this time, the production process capability is stable and consistent.

[0054] like Figure 5 As shown, Figure 5 The figure below shows the CPK distribution of the power of the TWS Bluetooth headset at the RF test station when the distance between the TWS Bluetooth headset and the coupling plate is 15mm. In the whole machine RF test station, the power index range of the TWS Bluetooth headset is -3dBm to 3dBm, the number of test samples is 2954, and its CPK index is 1.21. When the CPK index is less than 1.33, it indicates that the production process is not ideal and the production equipment is unstable, and improvements are needed to improve the production process capability and the stability of the production equipment.

[0055] From the CPK index statistics at the above distances of 6mm, 10mm and 15mm, it can be determined that when the distance is 10mm, it falls within the radiation near-field area of ​​8.30mm to 12.81mm of the TWS Bluetooth headset antenna, and the CPK index is greater than 1.33, the process is ideal, and the production process capability is stable and consistent at this time; when the distance is 6mm and 15mm, outside the radiation near-field area of ​​8.30mm to 12.81mm of the TWS Bluetooth headset antenna, the CPK index is less than 1.33, the production process is not ideal, and needs to be improved. Therefore, when the first distance between the Bluetooth headset and the coupling plate is at least within the first radiation near-field area, the test data of the Bluetooth module is stable and consistent.

[0056] The above embodiment verifies the use of a conventional coupling plate antenna size, whose antenna length is half a wavelength. In another embodiment of the present invention, the antenna size of the coupling plate is designed to be one-quarter of the working wavelength, that is, the radiation near-field range of the Bluetooth headset antenna and the coupling plate antenna partially overlaps.

[0057] In this embodiment, the antenna length of the TWS headset is designed to be 28mm, the inductive near field area of ​​the TWS Bluetooth headset antenna is less than 8.30mm, the radiation near field area of ​​the TWS Bluetooth headset antenna is between 8.30mm and 12.81mm, and the radiation far field area of ​​the TWS Bluetooth headset antenna is greater than 12.81mm. The antenna length of the coupling plate is designed to be one-quarter of the working wavelength. Substituting into the formula 0.62√(D^3 / λ) and 2D^2 / λ, it can be seen that the inductive near field area of ​​the coupling plate antenna is less than 9.49mm, the radiation near field area of ​​the coupling plate antenna is between 9.49mm and 15.30mm, and the radiation far field area of ​​the coupling plate antenna is greater than 15.30mm. Among them, 9.49mm~12.81mm is the overlapping part of the radiation near field area of ​​the TWS Bluetooth headset and the coupling plate.

[0058] Figure 6 This is a statistical chart of the distance between the TWS Bluetooth headset and the coupling plate and the test yield. The TWS headset antenna length is designed to be 28mm, and the coupling plate antenna length is designed to be one-quarter of the working wavelength, which is 122.45mm / 4=30.6mm.

[0059] Figure 6 The test data of the distance between TWS Bluetooth headsets and the coupling plate were divided into 3mm, 6mm, 8.3mm, 9.49mm, 10mm, 12.81mm, 15.3mm, 20mm and 30mm. The number of 2000 TWS Bluetooth headsets was counted in each test, and then the yield was calculated.

[0060] The sensing near field area of ​​the TWS Bluetooth headset antenna is within 8.30mm, such as Figure 6At the 3mm and 6mm distances in the inductive near field of the TWS Bluetooth headset antenna, there were 63 and 30 defective TWS Bluetooth headsets, with yields of 96.85% and 98.50% respectively. This shows that the TWS Bluetooth headset test is unstable and has poor consistency, which will increase the number of finished products for secondary and tertiary testing and disassembly repair. For factory production standards, a yield of less than 99% is unacceptable, and improvements must be made to increase the yield of TWS Bluetooth headsets to more than 99%.

[0061] As the distance between the TWS Bluetooth headset and the coupling plate increases, Figure 6 The radiation near-field area of ​​the TWS Bluetooth headset antenna is between 8.30mm and 12.81mm, and the radiation near-field area of ​​the coupling plate antenna is between 9.49mm and 15.30mm. 9.49mm to 12.81mm is the common radiation near-field area of ​​the TWS Bluetooth headset and the coupling plate. When the distance between the TWS Bluetooth headset and the coupling plate is 8.3mm, 9.49mm, 10mm and 12.81mm, respectively, the number of defective TWS Bluetooth headsets is significantly reduced, which are 14, 11, 10 and 15, respectively. The number of defectives is within 15, and the yield rate reaches 99.30%, 99.45%, 99.50% and 99.25%, respectively.

[0062] It can be determined that when the distance between the TWS Bluetooth headset and the coupling plate falls into the overlapping area of ​​its radiation near-field zone, that is, it falls into the radiation near-field zone of the TWS Bluetooth headset and the coupling plate at the same time, the test data stability is better, and the yield shows that the TWS Bluetooth headset has good consistency and stable product testing in the overlapping area of ​​the radiation near-field zone.

[0063] As the distance between the TWS headset and the coupling plate is further increased, the yield rate of the TWS Bluetooth headset gradually decreases. When the distance between the TWS Bluetooth headset and the coupling plate is 15.3mm, it exceeds the radiation near-field range of the TWS Bluetooth headset. At this time, there are 26 defective products with a yield rate of 98.70%, which enters the unqualified range. Moreover, the greater the distance between the TWS Bluetooth headset and the coupling plate, the faster the yield rate of the TWS Bluetooth headset decreases. When the distance between the TWS headset and the coupling plate is greater than 20mm, the yield rate of the TWS headset decreases more obviously. When the distance between the TWS headset and the coupling plate is 20mm and 30mm respectively, the yield rate of the TWS Bluetooth headset is 97.25% and 91.35% respectively. Obviously, this yield rate is seriously unacceptable.

[0064] Therefore, in this embodiment, it is a better choice to set the distance between the TWS Bluetooth headset and the coupling plate antenna in the overlapping area of ​​the two radiation near-field zones.

[0065] In a second aspect, an embodiment of the present invention provides a Bluetooth radio frequency testing device, such as Figure 7 As shown, it includes a radio frequency test system, a test device, a coupling plate 20 and a fixture 30. The radio frequency test system is configured with an application for controlling the test device to perform a Bluetooth radio frequency test. A fixture 30 for accommodating a Bluetooth module is provided on the coupling plate 20. The test device transmits data with the Bluetooth module through the coupling plate 20. The fixture 30 makes the distance between the Bluetooth module to be tested and the coupling plate 20 at least within the radiation near field of the Bluetooth module. Specifically, in this embodiment, the radio frequency test system is a computer with a radio frequency test application installed, and the radio frequency test system controls the test device to perform a radio frequency test. The distance between the Bluetooth module to be tested and the coupling plate 20 is adjusted by the fixture, so that the distance between the antenna of the Bluetooth module and the antenna of the coupling plate 20 is at least within the radiation near field of the Bluetooth module, so as to avoid the coupling effect caused by the distance between the antenna of the Bluetooth module and the antenna of the coupling plate 20 being too close to each other, resulting in interference and making the test data unstable. In another specific implementation scheme, the fixture makes the distance between the Bluetooth module to be tested and the coupling plate 20 be within the radiation near-field range of the Bluetooth module and the coupling plate 20 antenna at the same time. This range is the optimal test range of the Bluetooth module. Of course, it should be set according to the actual dimensions of the Bluetooth module and the coupling plate 20 antenna. In some cases, the radiation near-field range of the Bluetooth module and the coupling plate 20 antenna does not overlap.

[0066] The test equipment also includes a Bluetooth tester, a Bluetooth channel switch matrix and a shielding box 10. One end of the Bluetooth tester is connected to the radio frequency test system through a GPI B-USB card, and the other end is connected to the Bluetooth channel switch matrix. The coupling plate 20 is arranged in the shielding box 10. The shielding box 10 is also provided with a coaxial line 50 for connecting the coupling plate 20 and the shielding box SMA adapter (SubMiniature version A). The other end of the SMA adapter is connected to the Bluetooth channel switch matrix. The coupling plate 20 is connected to the Bluetooth tester through the Bluetooth channel switch matrix. The fixture 30 is provided with a groove 40 for accommodating the Bluetooth module, and the groove 40 matches the outer contour of the Bluetooth module. The groove 40 on the fixture can accommodate the Bluetooth module, so that the Bluetooth module can be placed more accurately when testing the Bluetooth module, and the antenna distance between the Bluetooth module and the coupling plate 20 can be accurately controlled.

[0067] The above is a specific description of the preferred implementation of the present invention, but the present invention is not limited to the above-mentioned implementation mode. Technical personnel familiar with the field can also make various equivalent deformations or substitutions under the shared conditions without violating the spirit of the present invention. These equivalent deformations or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A Bluetooth radio frequency testing method, characterized in that: Applied to a radio frequency test system, the radio frequency test system is configured with an application, a test device, and a coupling board for performing a Bluetooth radio frequency test, the test device performs data transmission with the Bluetooth module through the coupling board, and the method includes: Obtaining the working frequency of the antenna, and calculating the wavelength of the antenna electromagnetic wave according to the working frequency; Obtain a first size of the Bluetooth module antenna and a second size of the coupling plate antenna, and calculate a first inductive near-field region and a first radiative near-field region of the Bluetooth module antenna according to the first size and the wavelength; and calculate a second inductive near-field region and a second radiative near-field region of the coupling plate antenna according to the second size and the wavelength; A first distance between the Bluetooth module antenna and the coupling plate antenna is obtained, and the first distance is adjusted so that the first distance is at least within the first radiation near-field region.

2. The method according to claim 1, characterized in that The first distance is adjusted so that the first distance is simultaneously within the range of the first radiation near-field region and the second radiation near-field region.

3. The method according to claim 1 or 2, characterized in that: The operating frequency of the Bluetooth module antenna is 2.45 GHz.

4. The method according to claim 3, characterized in that The first size is designed to be one quarter of the wavelength, and the second size is designed to be one half of the wavelength.

5. The method according to claim 4, characterized in that The wavelength calculation formula is: Where λ is the working wavelength of the antenna, f is the working frequency of the antenna, μ r is the relative magnetic permeability, ε r is the relative dielectric constant, ν0 is the speed of light in vacuum.

6. The method according to claim 5, characterized in that The inductive near field region is The radiation near field region is Where r1 is the distance of the antenna sensing near field, r2 is the distance of the antenna radiating near field, D is the maximum geometric size of the antenna, and λ is the operating wavelength of the antenna.

7. A Bluetooth radio frequency test device, comprising a radio frequency test system, a test device, a coupling plate and a fixture, characterized in that: The radio frequency test system is configured with an application for controlling the test device to perform Bluetooth radio frequency testing. A fixture for accommodating the Bluetooth module is provided on the coupling plate. The test device performs data transmission with the Bluetooth module through the coupling plate. The fixture ensures that the distance between the Bluetooth module to be tested and the coupling plate is at least within the radiation near field of the Bluetooth module.

8. A Bluetooth radio frequency testing device according to claim 7, characterized in that: The fixture ensures that the distance between the Bluetooth module to be tested and the coupling plate is within the radiation near field range of the Bluetooth module and the coupling plate antenna.

9. A Bluetooth radio frequency testing device according to claim 8, characterized in that: The test equipment includes a Bluetooth test machine, a Bluetooth channel switch matrix and a shielding box. The Bluetooth test machine is connected to the radio frequency test system via a GPIB-USB card. The coupling plate is arranged in the shielding box. The coupling plate is connected to the Bluetooth test machine via the Bluetooth channel switch matrix.

10. A Bluetooth radio frequency testing device according to any one of claims 7 to 9, characterized in that: The fixture is provided with a groove for accommodating the Bluetooth module, and the groove matches the outer contour of the Bluetooth module.

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