Adaptive target and insertion loss calculation method thereof

Abstract

The invention provides an adaptive target and an insertion loss calculation method thereof. The adaptive target comprises a grounding structure and an inner conductor structure. A first through hole and a plurality of second through holes are formed in the grounding structure, the first through hole is formed in the center of the grounding structure, and the second through holes are formed in the edge of the grounding structure at intervals; a central conductor is arranged at one end of the inner conductor structure, an N-type interface is arranged at the other end of the inner conductor structure, the central conductor is connected with the N-type interface, and an insulator is arranged on the outer surface of the connecting position of the central conductor and the N-type interface; the grounding structure and the inner conductor structure are detachably connected; the central conductor is inserted into the first through hole and is coaxially arranged, and the outer diameter of the central conductor is smaller than the inner diameter of the first through hole. When electrostatic discharge current targets of different sizes need to be connected, the electrostatic discharge current target can be connected by selecting the grounding structure and the inner conductor structure which have the same size as the front side of the electrostatic discharge current target, so that the electrostatic discharge current target can be calibrated.

Description

Technical Field

[0001] The present invention relates to the technical field of calibrating electrostatic discharge current targets, and particularly relates to an adapter target and a calculation method for its insertion loss. Background Art

[0002] An electrostatic discharge current target is a standard device for calibrating an electrostatic discharge simulator. The electrostatic discharge current target can convert the discharge current of the electrostatic discharge simulator into a voltage. The front structure of the electrostatic discharge current target is as Figure 1 shown. From the outside to the inside, a grounding structure 1, an insulating gap 2, and an inner conductor 3 are sequentially arranged. A plurality of through holes 4 for connection are arranged on the grounding structure 1; the back of the electrostatic discharge current target is a coaxial structure, generally an N-type or SMA-type interface.

[0003] Insertion loss is the main calibration item for calibrating an electrostatic discharge current target. The calibration equipment is generally a vector network analyzer. Due to the mismatch between the front of the electrostatic discharge current target and the interface of the calibration equipment, the front of the electrostatic discharge current target and the interface of the calibration equipment cannot be directly connected. An adapter target is needed to physically connect the front of the electrostatic discharge current target and the interface of the calibration equipment. One end of the adapter target, that is, the diameter of the inner conductor on the front, should be equal to the diameter of the inner conductor 3 of the electrostatic discharge current target to be calibrated, and it should be able to be tightly and firmly connected to the electrostatic discharge current target. The other end, that is, the back, should be able to be connected to a coaxial cable. The function of the adapter target is to geometrically expand the diameter of the coaxial cable to the diameter of the electrostatic discharge current target to be calibrated, that is, to expand the diameter of the inner conductor of the coaxial cable to the diameter of the inner conductor 3 of the electrostatic discharge current target to be calibrated, and to expand the inner diameter of the outer conductor of the coaxial cable to the inner diameter of the grounding structure 1 of the electrostatic discharge current target to be calibrated.

[0004] However, the sizes of the electrostatic discharge current targets and adapter targets produced by different manufacturers are usually different, which results in the inability to connect the electrostatic discharge current targets and adapter targets produced by different manufacturers, and the calibration operation cannot be carried out smoothly. Summary of the Invention

[0005] The present invention provides an adapter target and a calculation method for its insertion loss to solve the technical problem that the electrostatic discharge current targets and adapter targets produced by different manufacturers cannot be connected.

[0006] To solve the above technical problem, the present invention provides an adapter target, including a grounding structure and an inner conductor structure; a first through hole and a plurality of second through holes are arranged on the grounding structure. The first through hole is arranged at the central position of the grounding structure, and the plurality of second through holes are arranged at intervals at the edge position of the grounding structure;

[0007] One end of the inner conductor structure is provided with a center conductor, and the other end is provided with an N-type interface. The center conductor is connected to the N-type interface, and an insulator is provided on the outer surface of the position where the center conductor is connected to the N-type interface.

[0008] The grounding structure and the inner conductor structure are detachably connected; the center conductor is inserted into the first through hole and coaxially arranged, and the outer diameter of the center conductor is smaller than the inner diameter of the first through hole.

[0009] Preferably, a groove is provided on the back surface of the grounding structure, and the groove is coaxially arranged with the first through hole; the inner conductor structure is provided with a connecting plate that cooperates with the groove, and the connecting plate is arranged between the center conductor and the N-type interface.

[0010] Preferably, a plurality of third through holes are provided on the connecting plate, and a plurality of screw holes that cooperate with the third through holes are provided in the groove. The connecting plate is detachably fixed in the groove through the third through holes, the screw holes and screws.

[0011] Preferably, the shape of the connecting plate is rectangular.

[0012] Preferably, the shape of the grounding structure is cylindrical.

[0013] Preferably, a plurality of the second through holes are arranged around the first through hole and are evenly arranged at the edge position of the grounding structure.

[0014] Preferably, the second through hole is a stepped hole, and the diameter of the second through hole near the front surface of the grounding structure is smaller than the diameter near the back surface of the grounding structure.

[0015] Preferably, the structure of the center conductor is cylindrical.

[0016] The present invention also provides a method for calculating the insertion loss of an adapter target. The method is used for the insertion loss of an adapter target described in any one of the above, and the method includes the following steps:

[0017] S1. Connect a test cable and an attenuator to the test ports of a vector network analyzer, and calibrate the vector network analyzer.

[0018] S2. After aligning and fixing the front surface of an adapter target and an electrostatic discharge current target link, connect it between the attenuator and the test cable, and record the S 21 magnitude value X of the vector network analyzer at each frequency.

[0019] S3. Replace the adapter target in step S2 with another adapter target, and record the S 21The numerical value Y of the modulus;

[0020] S4. After aligning and fixing the fronts of the two adaptor targets, connect them between the attenuator and the test cable, and record the S of the vector network analyzer at each frequency. 21 The numerical value Z of the modulus;

[0021] S5. Determine the insertion loss of the two adaptor targets according to the following formula, where I A represents the insertion loss of one adaptor target, and I B represents the insertion loss of the other adaptor target:

[0022]

[0023] Preferably, after step S5, the following steps are further included: Determine the error of the insertion loss introduced by imperfect processing of the adaptor target according to the following formula, where ΔΓ represents the error of the reflection coefficient of the adaptor target surface represented linearly, and ΔS 21 represents the error of the insertion loss of the adaptor target, and ΔZ all represents the total deviation of the characteristic impedance of the adaptor target, and Z0 represents the theoretical characteristic impedance calculated for the adaptor target according to the design parameters;

[0024]

[0025] The present invention provides an adaptor target and a calculation method for its insertion loss. The adaptor target includes a grounding structure and an inner conductor structure, and the grounding structure and the inner conductor structure are detachably connected. When the adaptor target needs to be connected to electrostatic discharge current targets of different sizes produced by different manufacturers, a grounding structure and an inner conductor structure with the same front size as the electrostatic discharge current target can be selected. After connecting the grounding structure and the inner conductor structure to form the adaptor target, the front of the adaptor target and the front of the electrostatic discharge current target can be fitted. The adaptor target and the electrostatic discharge current target can be connected through a plurality of second through holes, a plurality of bolts and a plurality of nuts, thereby calibrating the electrostatic discharge current target and improving the calibration efficiency. Through the calculation method of the insertion loss of the adaptor target, the insertion loss of the adaptor target can be calculated. Description of the Drawings

[0026] Figure 1 is a schematic front view of the structure of an electrostatic discharge current target in the prior art.

[0027] Figure 2 is a schematic front view of the grounding structure of an adaptor target provided by an embodiment of the present invention.

[0028] Figure 3 is a schematic back view of the grounding structure of an adaptor target provided by an embodiment of the present invention.

[0029] Figure 4 Yes Figure 3 is the schematic cross-sectional view of A-A.

[0030] Figure 5 is the schematic view of the back structure of an inner conductor structure of an adapter target provided by an embodiment of the present invention.

[0031] Figure 6 is the schematic view of the side structure of an inner conductor structure of an adapter target provided by an embodiment of the present invention.

[0032] Figure 7 is the schematic circuit connection diagram of self-calibration of a vector network analyzer provided by an embodiment of the present invention.

[0033] Figure 8 is the schematic diagram after the vector network analyzer, the adapter target and the electrostatic discharge current target link are connected after self-calibration provided by an embodiment of the present invention.

[0034] Figure 9 is the flowchart of a calculation method for the insertion loss of an adapter target provided by an embodiment of the present invention.

[0035] The reference numerals are as follows:

[0036] Grounding structure - 1, Insulation gap - 2, Inner conductor - 3, Through hole - 4;

[0037] Adapter target - 10;

[0038] Grounding structure - 11, Inner conductor structure - 12, Insulator - 13;

[0039] First through hole - 111, Second through hole - 112, Groove - 113, Screw hole - 114;

[0040] Center conductor - 121, N-type interface - 122, Connection plate - 123, Third through hole - 124. Detailed implementation manners

[0041] To make the objectives, advantages and features of the present invention clearer, the following further describes in detail an adapter target and a calculation method for its insertion loss proposed by the present invention with reference to the accompanying drawings. It should be noted that the accompanying drawings are all in very simplified forms and use non-precise scales, and are only used to conveniently and clearly assist in explaining the objectives of the embodiments of the present invention.

[0042] In the description of the present invention, the qualifiers such as "first" and "second" are added for convenient description and reference, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with qualifiers such as "first" and "second" may explicitly or implicitly include one or more of such features.

[0043] As Figures 2 - 6 and Figure 8 shown, this embodiment provides an adapter target 10, including a grounding structure 11 and an inner conductor structure 12; a first through hole 111 and a plurality of second through holes 112 are provided on the grounding structure 11, the first through hole 111 is arranged at the central position of the grounding structure 11, and the plurality of second through holes 112 are arranged at intervals at the edge position of the grounding structure 11; one end of the inner conductor structure 12 is provided with a central conductor 121, the other end is provided with an N-type interface 122, the central conductor 121 and the N-type interface 122 are connected, and an insulator 13 is arranged on the outer surface of the connected position of the central conductor 121 and the N-type interface 122; the grounding structure 11 and the inner conductor structure 12 are detachably connected; the central conductor 121 is inserted into the first through hole 111 and coaxially arranged, and the outer diameter of the central conductor 121 is smaller than the inner diameter of the first through hole 111. Among them, the material of the grounding structure 11 can be stainless steel; the material of the insulator 13 can be polytetrafluoroethylene; the material of the central conductor 121 can be beryllium bronze, with a gold-plated surface.

[0044] The adapter target 10 provided by this embodiment includes a grounding structure 11 and an inner conductor structure 12, and the grounding structure 11 and the inner conductor structure 12 are detachably connected. When the adapter target 10 needs to be connected to electrostatic discharge current targets of different sizes produced by different manufacturers, a grounding structure 11 and an inner conductor structure 12 with the same front size as the electrostatic discharge current target can be selected. After connecting the grounding structure 11 and the inner conductor structure 12 to form the adapter target 10, the front surface of the adapter target 10 and the front surface of the electrostatic discharge current target can be fitted, and the adapter target 10 and the electrostatic discharge current target can be connected through a plurality of second through holes 112, a plurality of bolts and a plurality of nuts, thereby calibrating the electrostatic discharge current target and improving the calibration efficiency.

[0045] Preferably, as Figures 3 - 6 shown, a groove 113 is arranged on the back surface of the grounding structure 11, and the groove 113 is coaxially arranged with the first through hole 111; the inner conductor structure 12 is provided with a connecting plate 123 that matches the groove 113, and the connecting plate 123 is arranged between the central conductor 121 and the N-type interface 122. Installing the connecting plate 123 in the groove 113 can improve the firmness between the inner conductor structure 12 and the grounding structure 11 and prevent the inner conductor structure 12 from shaking. The insulator 13 can isolate the central conductor 121 and the connecting plate 123, thereby insulating the central conductor 121 and the grounding structure 11.

[0046] Preferably, as Figures 3 - 6As shown, a plurality of third through holes 124 are provided on the connecting plate 123, and a plurality of screw holes 114 mating with the third through holes 124 are provided in the groove 113. The connecting plate 123 is detachably fixed in the groove 113 through the third through holes 124, the screw holes 114 and screws. The inner conductor structure 12 can be conveniently installed and disassembled by screws. In other embodiments, the center conductor 121 can be connected to the grounding structure 11 by bolts or buckles, etc.

[0047] Preferably, as Figure 5 and Figure 6 shown, the connecting plate 123 is rectangular in shape, which is convenient for machining the connecting plate 123.

[0048] Preferably, as Figures 2 - 4 shown, the grounding structure 11 is cylindrical in shape. Combining Figure 1 and Figure 8 shown, the front of the current electrostatic discharge current target is usually circular. In order to make the front of the electrostatic discharge current target fit and have the same size as the front of the adapter target 10, the grounding structure 11 of the adapter target 10 is designed to be cylindrical.

[0049] Preferably, as Figure 2 shown, a plurality of the second through holes 112 are arranged around the first through hole 111 and are uniformly arranged at the edge position of the grounding structure 11. Combining Figure 1 and Figure 8 shown, a plurality of second through holes 112 can be aligned with the through holes 4 on the front of the electrostatic discharge current target, and the adapter target 10 and the electrostatic discharge current target can be fixed by bolts and nuts. The plurality of second through holes 112 are uniformly distributed, which can improve the firmness between the adapter target 10 and the electrostatic discharge current target.

[0050] Preferably, as Figure 4 shown, the second through hole 112 is a stepped hole, and the diameter of the second through hole 112 near the front of the grounding structure 11 is smaller than the diameter near the back of the grounding structure 11, so that the bolt head or nut for fixing can sink into the end with the larger diameter of the second through hole 112, preventing the bolt head or nut from winding the test cable.

[0051] Preferably, as Figure 6 shown, the structure of the center conductor 121 is cylindrical, which can provide the contact area between the center conductor 121 and the inner conductor of the electrostatic discharge current target.

[0052] As Figure 9As shown, based on the same technical concept as the above-mentioned one kind of adapter target, this embodiment provides a calculation method for the insertion loss of an adapter target. The method is used to calculate the insertion loss of one kind of adapter target described in any of the above, and the method includes the following steps:

[0053] S1. As Figure 7 shown, connect a test cable and an attenuator to the test ports of a vector network analyzer, and calibrate the vector network analyzer.

[0054] S2. As Figure 8 shown, after aligning and fixing the front face of an adapter target 10 with the positive face of an electrostatic discharge current target link, connect it between the attenuator and the test cable, and record the numerical value X of the S 21 mode value of the vector network analyzer at each frequency; wherein, the electrostatic discharge current target link includes an electrostatic discharge current target and its own attenuator, and the front face of the electrostatic discharge current target link refers to the front face of the electrostatic discharge current target.

[0055] S3. Referring to Figure 8 shown, replace the adapter target 10 in step S2 with another adapter target 10, and record the numerical value Y of the S 21 mode value of the vector network analyzer at each frequency.

[0056] S4. Referring to Figure 8 shown, after aligning and fixing the front faces of the two adapter targets 10, connect them between the attenuator and the test cable, and record the numerical value Z of the S 21 mode value of the vector network analyzer at each frequency; at this time, the following formula can be obtained:

[0057]

[0058] wherein, I EUT represents the insertion loss of the electrostatic discharge current target link, and the units of each item in formula 1 are all dB.

[0059] S5. Determine the insertion losses of the two adapter targets 10 according to the following formula, wherein I A represents the insertion loss of one adapter target 10, and I B represents the insertion loss of another adapter target 10:

[0060]

[0061] The calculation method for the insertion loss of an adapter target 10 provided in this embodiment can calculate the insertion loss of the adapter target 10. When calibrating an electrostatic discharge current target with the adapter target 10, the measurement result of the insertion loss of the calibrated electrostatic discharge current target can be corrected by the insertion loss of the adapter target 10 to remove the insertion loss introduced by the adapter target 10.

[0062] During the processing of the adapter target 10, it is usually not completely ideal, and imperfect processing will introduce errors in insertion loss. The imperfect processing of the adapter target 10 is mainly reflected in that the characteristic impedance of the adapter target 10 deviates from the standard value (50 Ω).

[0063] There is a formula for the characteristic impedance of a coaxial cable:

[0064]

[0065] where Z0 is the theoretical characteristic impedance of the coaxial cable calculated according to the design parameters;

[0066] c0 is the permittivity in free space;

[0067] μ0 is the permeability in free space;

[0068] ε r is the relative permittivity. In this embodiment, the material is polytetrafluoroethylene, and ε r can be taken as 2.1;

[0069] D is the inner diameter of the outer conductor of the coaxial cable, that is, the inner diameter of the grounding structure of the adapter target;

[0070] d is the outer diameter of the inner conductor of the coaxial cable, that is, the outer diameter of the center conductor of the adapter target;

[0071] The factors affecting the accuracy of the characteristic impedance of the coaxial cable are:

[0072] 1) Deviations in the diameters of the inner and outer conductors

[0073] Deviations in the diameters of the inner and outer conductors caused by mechanical processing will affect the characteristic impedance of the coaxial cable. Let the outer diameter deviation of the inner conductor be Δd and the inner diameter deviation of the outer conductor be ΔD. Then the actual characteristic impedance of the adapter target is:

[0074]

[0075] The deviation in the characteristic impedance of the coaxial cable caused by the deviations in the diameters of the inner and outer conductors is:

[0076]

[0077] Generally, Δd is much smaller than d, and ΔD is much smaller than D. Therefore, there is:

[0078]

[0079] The relative error is:

[0080]

[0081] 2) Eccentricity between the inner and outer conductors

[0082] The characteristic impedance formula of the eccentric coaxial line is as follows:

[0083]

[0084] Where, e —— Eccentricity;

[0085] In the case of a small eccentricity, there is an approximate formula:

[0086]

[0087] Therefore, the deviation of the characteristic impedance caused by the eccentricity between the inner and outer conductors is:

[0088]

[0089] 3) Influence of other imperfect mechanical processing

[0090] The ellipticity of the surfaces of the inner and outer conductors will theoretically also cause an error in the characteristic impedance. However, with modern mechanical processing technology, as long as the ellipticity is within the diameter tolerance range, it can be ignored.

[0091] Regarding the actual influence of the surface finish on the characteristic impedance, it is generally considered that when the surface finish of the inner and outer conductors is within the diameter tolerance, its influence on the characteristic impedance is not considered.

[0092] The influence of imperfect mechanical processing on the characteristic impedance of the adapter target is caused by the superposition of these factors. Considering the relatively large ΔZ and ΔZ′ among them, the total deviation ΔZ of the characteristic impedance caused by imperfect mechanical processing all = |ΔZ + ΔZ′|. According to the measurement results of the diameter, eccentricity, etc. of the actually processed adapter target, using the above formula, the error of the characteristic impedance of the adapter target relative to the standard value can be calculated more accurately. Then, according to formula (12) - formula (13), the error introduced by the imperfect processing of the adapter target on the insertion loss measurement can be calculated.

[0093]

[0094] Where, ΔΓ —— The error of the reflection coefficient of the adapter target surface represented linearly;

[0095] ΔS 21 —— The transmission coefficient from the adapter target surface to the coaxial end face, that is, the error of the insertion loss, dB;

[0096] ΔZ all —— The total deviation of the characteristic impedance of the adapter target, Ω;

[0097] Z0 —— The theoretical characteristic impedance calculated for the adapter target according to the design parameters, Ω.

[0098] The result after adding Formula (13) and Formula (2) represents the final insertion loss of the adapter target when there is a machining error.

[0099] In summary, an adapter target 10 provided by the present invention and a calculation method for its insertion loss. The adapter target 10 includes a grounding structure 11 and an inner conductor structure 12, and the grounding structure 11 and the inner conductor structure 12 are detachably connected. When the adapter target 10 needs to be connected to electrostatic discharge current targets of different sizes produced by different manufacturers, a grounding structure 11 and an inner conductor structure 12 with the same front size as the electrostatic discharge current target can be selected. After connecting the grounding structure 11 and the inner conductor structure 12 to form the adapter target 10, the front surface of the adapter target 10 and the front surface of the electrostatic discharge current target can be fitted. The adapter target 10 and the electrostatic discharge current target can be connected through a plurality of second through holes 112, a plurality of bolts and a plurality of nuts, thereby calibrating the electrostatic discharge current target and improving the calibration efficiency. Through the calculation method of the insertion loss of the adapter target 10, the insertion loss of the adapter target 10 can be calculated.

[0100] The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art according to the above disclosure are within the protection scope of the present invention.

Claims

1. An adaptation target, characterized in that, It includes a grounding structure and an inner conductor structure; a first through-hole and a plurality of second through-holes are provided on the grounding structure, the first through-hole is arranged at the central position of the grounding structure, and the plurality of second through-holes are arranged at intervals at the edge position of the grounding structure; One end of the inner conductor structure is provided with a central conductor, and the other end is provided with an N-type interface. The central conductor is connected to the N-type interface, and an insulator is provided on the outer surface of the position where the central conductor and the N-type interface are connected; The grounding structure and the inner conductor structure are detachably connected; the central conductor is inserted into the first through-hole and coaxially arranged, and the outer diameter of the central conductor is smaller than the inner diameter of the first through-hole.

2. The adapter target according to claim 1, wherein A groove is provided on the back surface of the grounding structure, and the groove is coaxially arranged with the first through-hole; the inner conductor structure is provided with a connecting plate that matches the groove, and the connecting plate is arranged between the central conductor and the N-type interface.

3. The adapter target according to claim 2, characterized in that, A plurality of third through-holes are provided on the connecting plate, a plurality of screw holes that match the third through-holes are provided in the groove, and the connecting plate is detachably fixed in the groove through the third through-holes, the screw holes and screws.

4. The adaptation target according to claim 2, wherein The shape of the connecting plate is rectangular.

5. An adaptation target according to claim 1, characterized in that, The shape of the grounding structure is cylindrical.

6. The adapter target according to claim 1, wherein The plurality of second through-holes surround the first through-hole and are evenly arranged at the edge position of the grounding structure.

7. The adaptation target according to claim 1, wherein The second through-hole is a stepped hole, and the diameter of the second through-hole close to the front surface of the grounding structure is smaller than the diameter close to the back surface of the grounding structure.

8. An adaptation target as claimed in claim 1, wherein, The structure of the central conductor is cylindrical.

9. A calculation method for adapting the insertion loss of a target, characterized in that, The method is used to calculate the insertion loss of an adapter target according to any one of claims 1-8, and the method includes the following steps: S1. Connect a test cable and an attenuator to the test ports of a vector network analyzer, and calibrate the vector network analyzer; S2. After aligning and fixing the front face of an adapter target and an electrostatic discharge current target link, connect it between the attenuator and the test cable, and record the value X of the S modulus value of the vector network analyzer at each frequency. 21 Modulus value S3. Replace the matching target in step S2 with another matching target, and record the S 21 magnitude value Y of the vector network analyzer at each frequency; S4. After aligning and fixing the fronts of the two adaptation targets, connect them between the attenuator and the test cable, and record the value Z of the S modulus of the vector network analyzer at each frequency; 21 Modulus value Z; S5. Determine the insertion loss of the two said adapted targets according to the following formula, where I A represents the insertion loss of one adapted target, and I B represents the insertion loss of the other adapted target:

10. A method for calculating the insertion loss of an adapter target as described in claim 9, characterized in that, After step S5, the following steps are further included: determining the error of the insertion loss introduced by the imperfect machining of the adaptor target through the following formula, where ΔΓ represents the error of the reflection coefficient of the adaptor target surface linearly expressed, and ΔS 21 represents the error of the insertion loss of the adaptor target, and ΔZ all represents the total deviation of the characteristic impedance of the adaptor target, and 0 represents the theoretical characteristic impedance calculated by the adaptor target according to the design parameters;

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