Reentrant resonant cavity for measuring loss of ceramic cup

Abstract

The utility model discloses a reentrant resonant cavity for ceramic cup loss measurement, and relates to the technical field of ceramic cup loss measurement. Comprising a metal shell, an opening is formed in the top of the metal shell, and a metal cover is connected to the opening; an upper supporting piece and a lower supporting piece are arranged in the cavity, the upper end of the upper supporting piece is connected with the metal cover body, the lower supporting piece is arranged at the bottom of the cavity, and a gap space used for containing a ceramic cup is formed between the upper supporting piece and the lower supporting piece; an inductance area is formed in an annular space between the inner side wall of the metal shell and the upper supporting piece or between the inner side wall of the metal shell and the upper supporting piece and the lower supporting piece, coupling elements are arranged in the inductance area or the capacitance area, at least two interfaces are formed in the side wall of the cavity, and the interfaces are connected with the corresponding coupling elements. The resonant cavity is used for measuring ceramic loss, the ceramic cup workpiece is not damaged, the measuring speed is high, the consistency of measuring results is good, and the resonant cavity is suitable for loss detection of ceramic cup workpieces in batches.

Description

Technical Field

[0001] This utility model relates to the field of ceramic cup loss measurement technology, and more specifically, to a re-entry resonant cavity for measuring the loss of ceramic cups. Background Technology

[0002] In the semiconductor device manufacturing process, an important step is to add impurities to the semiconductor wafer's lattice by implanting ions into it in a vacuum, thereby altering its conductivity. The equipment used for this step is called an ion implanter, which is typically used to ionize semiconductor impurity atoms into ions and then accelerate their implantation into the semiconductor wafer.

[0003] The radio frequency (RF) accelerator chamber is a crucial component in high-energy ion implanters used to accelerate ions. The ceramic cup, as a key component of the RF accelerator chamber, serves two main functions: hermetical isolation and electrical isolation.

[0004] When the ion implanter is operating normally, the ceramic cup is not only subjected to the strong electromagnetic field within the radio frequency accelerator chamber, but also occasionally bombarded by the non-clustered high-energy ion beam within the beam cavity, making the working environment extremely harsh. Furthermore, the ceramic cup with a high loss tangent experiences rapid temperature rise and thermal expansion during operation, resulting in the following effects:

[0005] 1. Thermal expansion alters the fit dimensions of the RF accelerator barrel structure, resulting in increased reflected power and affecting the RF accelerator barrel's performance and ion acceleration efficiency.

[0006] 2. Temperature rise will cause the sealing ring in contact with the ceramic cup to age and coke, shorten the service life of the sealing ring, and lead to seal failure and SF6 gas leakage from the radio frequency accelerator barrel.

[0007] 3. When the temperature of the ceramic cup changes drastically, the temperature gradient causes the ceramic cup to crack. SF6 gas in the RF accelerator barrel rushes into the beam cavity, causing the vacuum in the beam cavity to deteriorate rapidly, which leads to the shutdown of the ion implanter. A large amount of reflected power may also damage the RF accelerator barrel and RF power supply.

[0008] As a key component of the radio frequency accelerator, the ceramic cup is highly susceptible to defects, which can significantly impact the stable operation of the ion implanter. An ion implanter typically uses around 20 ceramic cups, and all should be inspected to ensure each piece is of good quality. Currently, performance testing of ceramic cups involves randomly sampling a portion and sending them to a professional ceramic testing institution to produce standard round or square pieces, typically a round piece with a size of φ30x2mm. This process damages the ceramic cups during sample production, rendering some of the submitted pieces unusable. Furthermore, the sampling coverage is insufficient to guarantee the performance of the entire batch of ceramic cups. Additionally, testing is often time-consuming and costly, impacting production activities.

[0009] Another way to test ceramic cups is to assemble them with other components into an RF accelerator barrel, and then conduct high-power tests on a specially built platform to verify the stability of the ceramic cup under long-term high-power operation. However, in the application scenario of high-energy ion implanters, the assembly and testing of the RF barrel accelerator is time-consuming, labor-intensive, and energy-intensive. It often requires multiple technicians to spend one to two days or even longer to test the quality of a single ceramic cup, thus making it impossible to perform full inspection. Utility Model Content

[0010] In view of this, the main objective of this invention is to provide a re-entry resonant cavity for measuring ceramic losses. The resonant cavity used in this invention measures ceramic losses without damaging the ceramic cup workpiece itself, and also offers fast measurement speed and good consistency of measurement results, making it suitable for loss detection of batches of ceramic cup workpieces.

[0011] To achieve the above objectives, the technical solution of this utility model is as follows:

[0012] A re-entry resonant cavity for measuring ceramic loss includes a cylindrical metal shell with an opening at the top and a cavity formed inside. A metal cover for opening or closing the opening is connected to the opening.

[0013] The cavity contains an upper support and a lower support. The upper end of the upper support is connected to the metal cover. The lower support is located at the bottom of the cavity and corresponds vertically to the upper support. Both the upper and lower supports are made of metal. A gap space for placing a ceramic cup is formed between the upper and lower supports, and this gap space is a capacitance area. An inductive area is formed between the inner wall of the metal shell and the upper support, or between the inner wall of the metal shell and the upper and lower supports. A coupling element is provided in the inductive area or the capacitance area. At least two interfaces are provided on the side wall of the cavity, and the interfaces are connected to the corresponding coupling elements.

[0014] Furthermore, the upper support member includes a connector and a ceramic cover connected to the lower end of the connector. The lower end of the ceramic cover has a groove. The lower support member includes a ceramic support, which is located in the groove and forms a gap space with the inner sidewall of the groove.

[0015] Furthermore, the connector is cylindrical or an inverted frustum shape.

[0016] Furthermore, the ceramic support is frustum-shaped, and the groove is also frustum-shaped.

[0017] Furthermore, the upper end of the ceramic holder is formed with a step extending along the entire circumference.

[0018] Furthermore, a first through hole is coaxially formed through the center of the connector and the ceramic cover, and a second through hole is formed through the center of the ceramic support;

[0019] The interface includes a first interface disposed on the metal cover and a second interface disposed at the bottom of the metal housing;

[0020] The coupling element includes a first probe and a second probe. The first probe is disposed in the first through hole, with its lower end extending to the capacitor region and its upper end connected to the first interface. The second probe is disposed in the second through hole, with its upper end extending to the capacitor region and its lower end connected to the second interface.

[0021] Furthermore, the interface includes a third interface and a fourth interface disposed on the side wall of the metal housing and symmetrically distributed from left to right. The coupling element includes a first coupling piece and a second coupling piece, which are symmetrically distributed from left to right in the inductor region. The first coupling piece is connected to the third interface, and the second coupling piece is connected to the fourth interface.

[0022] The second objective of this invention is to provide an application of any of the above-described reentrant resonant cavities in the measurement of loss tangent in ceramic cups.

[0023] Furthermore, the application specifically includes the following steps:

[0024] The upper support component is assembled with the metal cover.

[0025] Open the metal lid and place the ceramic cup to be measured upside down on the lower support.

[0026] The metal cap is connected to the metal shell to form an enclosed internal space. At this time, the lower end of the upper support is placed on the outer peripheral side wall of the ceramic cup to be measured.

[0027] Connect the coupling elements in the inductor or capacitor region to the corresponding interfaces on the sidewall of the cavity.

[0028] Then connect the interface to the port of the vector network analyzer and use the vector network analyzer to measure the Q value in the lowest resonance mode of the resonant cavity;

[0029] The magnitude of the loss tangent of the ceramic cup to be tested is determined based on the Q value.

[0030] Compared with the prior art, this utility model has the following advantages:

[0031] This invention provides a re-entry resonant cavity for measuring the loss of ceramic cups. The cavity can be used to detect the loss of ceramic cups, and the Q-value of the cavity characterizes the difference in loss. In terms of the detection method, this invention does not damage the ceramic cup, maintaining the integrity and reusability of the ceramic cup workpiece. The assembly and testing of a single ceramic cup is quick and efficient, overcoming the shortcomings of conventional ceramic loss detection methods, which require damaging the ceramic cup to create a sample and have a long testing time. It eliminates the need to measure the absolute value of the ceramic cup's loss tangent; only the magnitude of the Q-value of the resonant mode in this device needs to be compared. This is very useful for quickly screening ceramic cups with relatively small loss tangent values ​​from a large number of ceramic cups.

[0032] In terms of detection capabilities, the shapes of the upper and lower support components, namely the ceramic lid and ceramic holder, can be changed to match various irregularly shaped ceramic cups. The volume of the inductor region, the area of ​​the capacitor region, and the gap can be changed to adapt to different operating frequencies of ceramic cups. At the same time, this utility model provides two methods for resonant cavity energy coupling: the probe method and the coupling plate method, which have the ability to detect loss tangent in irregularly shaped ceramic cups over a wide frequency band. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0034] Figure 1 This is a schematic diagram of the re-entry resonant cavity in this utility model.

[0035] Figure 2 This is a schematic diagram of the reentrant resonant cavity of this utility model in use.

[0036] Figure 3 This is a schematic diagram of the structure of the gap space in this utility model.

[0037] Figure 4 This is a schematic diagram of the structure of the ceramic cover in this utility model.

[0038] Figure 5 This is a schematic diagram of the structure of the ceramic holder in this utility model.

[0039] Figure 6 This is a schematic diagram of the shell structure in this utility model.

[0040] Figure 7 This is a schematic diagram of the structure of the ceramic cup in this utility model.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1. Metal casing; 11. Opening; 12. Cavity;

[0043] 2. Metal cover; 3. Upper support; 31. Connector; 311. First through hole; 32. Ceramic cover; 321. Groove; 322. Flange; 323. Groove step;

[0044] 4. Lower support component; 41. Ceramic support; 411. Step; 412. Second through hole; 5. Gap space; 51. Horizontal section; 52. Inclined section;

[0045] 6. Annular space; 7. Coupling element; 71. First probe; 72. Second probe; 73. First coupling plate; 74. Second coupling plate;

[0046] 8. Interface; 81. First Interface; 82. Second Interface; 83. Third Interface; 84. Fourth Interface;

[0047] 9. Ceramic cup. Detailed Implementation

[0048] Many specific details are set forth in the following description to provide a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0050] Unless otherwise specified, all materials used in this invention are available from commercial products in the field.

[0051] The structure provided by this utility model will be explained and described in detail below with reference to the accompanying drawings.

[0052] refer to Figures 1 to 7 As shown, this embodiment specifically discloses a re-entry resonant cavity for measuring the loss of a ceramic cup, including a cylindrical metal shell 1. The diameter of the metal shell 1 can be adaptively adjusted according to actual needs. An opening 11 is provided at the top of the metal shell 1, and a cavity 12, i.e., a resonant cavity, is formed inside. A metal cover 2 for opening or closing the opening 11 is connected to the opening 11. In the illustrated embodiment, the metal cover 2 and the metal shell 1 are detachably connected and fixed by multiple screws.

[0053] The cavity 12 is provided with an upper support 3 and a lower support 4. The upper end of the upper support 3 is connected to the metal cover 2. The lower support 4 is located at the bottom of the cavity 12 and corresponds to the upper support 3. Both the upper support 3 and the lower support 4 are made of metal. A gap space 5 for placing the ceramic cup 9 is formed between the upper support 3 and the lower support 4. The gap space 5 is the main capacitance area. An inductance area is formed between the inner wall of the metal shell 1 and the upper support 3, or between the inner wall of the metal shell 1 and the upper support 3 and the lower support 4. A coupling element 7 is provided in the inductance area or capacitance area. At least two interfaces 8 are provided on the side wall of the cavity 12. The interfaces 8 are connected to the corresponding coupling elements 7.

[0054] Specifically, in some embodiments, the lower periphery of the upper support member 3 completely covers the lower support member 4. In this case, the annular space 6 between the inner wall of the metal housing 1 and the upper support member 3 forms an inductive region. In some other embodiments, the upper support member 3 partially or completely does not cover the lower support member 4. In this case, the annular space 6 between the inner wall of the metal housing 1 and the upper support member 3 and the lower support member 4 forms an inductive region.

[0055] The formulas for resonant frequency relative to inductance and capacitance are as follows:

[0056]

[0057] As can be seen from the formula, as the inductance and capacitance values ​​increase, the resonant frequency of the resonant cavity decreases. The gap width of the gap space, the relative area between the upper support 3 and the lower support 4, and the dielectric constant of the ceramic cup 9 can all affect the capacitance, thereby changing the resonant frequency of the resonant cavity. Therefore, the resonant cavity can have the ability to measure a wider range of resonant frequencies.

[0058] In this embodiment, the ceramic cup 9 is placed directly on the lower support 4, and then connected to the corresponding interface 8 through the two ports of an external vector network analyzer. The Q value of the resonant cavity in the lowest resonant mode is measured. Generally, when the loss of the ceramic cup 9 is high, more energy is consumed by the cavity on the ceramic cup 9, and the Q value of the resonant cavity will decrease, thus achieving the purpose of detecting the loss of the ceramic cup in this invention. That is, by comparing the Q value of the resonant cavity when different ceramic cups 9 are installed, the purpose of detecting the loss of the ceramic cup is achieved.

[0059] Of course, it is important to note that good contact and conductivity should be maintained between the components of the resonant cavity; otherwise, it will greatly affect the Q value and resonant frequency of the resonant cavity, making the measurement results incomparable.

[0060] Combination Figures 3 to 5The upper support member 3 includes a connector 31 and a ceramic cover 32 connected to the lower end of the connector 31. Both the connector 31 and the ceramic cover 32 are made of metal. The lower end of the ceramic cover 32 has a groove 321. The lower support member 4 includes a ceramic support 41, which is also made of metal. The ceramic support 41 is located in the groove 321 and a gap space 5 is formed between it and the inner sidewall of the groove 321. The ceramic support 41 is frustum-shaped, and the groove 321 is also frustum-shaped, so that the longitudinal section of the gap space 5 has a horizontal section 51 and an inclined section 52 that slopes downward along both ends of the horizontal section 51. The angle between the inclined section 52 and the horizontal section 51 is an obtuse angle. In this embodiment, by setting the ceramic cover 32, the relative area between the upper support 3 and the lower support 4, i.e., the ceramic holder 41, can be increased. At the same time, by appropriately reducing the width of the gap between them, the width dimension is made to be consistent with the thickness of the ceramic cup 9's wall. This ensures that the ceramic cup 9 can be placed smoothly, while minimizing the width of the gap space, increasing the value of capacitance C, and thereby adjusting the resonant frequency of the resonant cavity. This makes the resonant frequency value consistent with the resonant frequency of the ceramic cup 9 in the actual use scenario, making the test conditions more consistent with the actual use scenario and ensuring the test effect.

[0061] Of course, in some other embodiments, if the resonant frequency of the actual use scenario of the ceramic cup 9 is higher, the width of the gap space 5 and the size of the relative area of ​​the upper and lower parts can be adjusted appropriately to reduce the value of the capacitor C and achieve the adjustment of the resonant frequency.

[0062] The connector 31 and the ceramic cover 32 can be integrally formed, or they can be detachably connected and fixed with screws, making it easy to replace the ceramic cover 32 with different shapes as needed. At the same time, the connector 31 and the metal cover 2, as well as the ceramic support 41 and the bottom of the metal shell 1, can be detachably connected and fixed with screws.

[0063] In some embodiments, the connector 31 is cylindrical or inverted frustum-shaped; its structure can be adjusted as needed; in some embodiments, a connector can also be provided at the bottom of the ceramic support 41 of the lower support 4 to support the ceramic support 41 and adjust the value of L in the inductance region.

[0064] Continue to refer to Figure 5 As shown, the upper end of the ceramic holder 41 has a step 411 extending along the entire circumference, which adapts to the bottom of the ceramic cup 9 and fits snugly against the bottom of the ceramic cup 9. In some other embodiments, the shape of the ceramic holder 41 can also be adjusted according to the specific shape of the ceramic cup 9 to be tested.

[0065] Continue to refer to Figure 2As shown in the first embodiment of this example, the connector 31 and the ceramic cover 32 are provided with a coaxial first through hole 311 through their centers, and the ceramic support 41 is provided with a through second through hole 412 through its center.

[0066] Interface 8 includes a first interface 81 disposed on the metal cover 2 and a second interface 82 disposed at the bottom of the metal housing 1;

[0067] The coupling element 7 includes a first probe 71 and a second probe 72. The first probe 71 is disposed in the first through hole 311, with its lower end extending to the capacitor region and its upper end connected to the first interface 81. The second probe 72 is disposed in the second through hole 412, with its upper end extending to the capacitor region and its lower end connected to the second interface 82. In this embodiment, energy coupling tests can be performed on the resonant cavity using the first probe 71 and the second probe 72, and the tests can be performed using an external vector network analyzer.

[0068] Combination Figure 1 As shown, this is the second implementation method in this embodiment. The interface 8 includes a third interface 83 and a fourth interface 84 symmetrically distributed on the sidewall of the metal housing 1. The coupling element 7 includes a first coupling piece 73 and a second coupling piece 74, symmetrically distributed in the inductance region, i.e., the annular space 6. The first coupling piece 73 is connected to the third interface 83, and the second coupling piece 74 is connected to the fourth interface 84. In this embodiment, the coupling piece method is used for capability coupling testing. Compared to using a probe, the probe's small size and uncertain insertion length during insertion into the through-hole result in a more stable test structure. Furthermore, when using the coupling piece method, as shown in the figure, through-holes are not required in the upper support 3 and lower support 4, reducing the processing steps of the device.

[0069] This utility model embodiment also provides the application of any of the above-mentioned reentrant resonant cavities in the measurement of loss tangent in ceramic cups; the application specifically includes the following steps:

[0070] The upper support 3 is assembled with the metal cover 2;

[0071] Open the metal cover 2 and place the ceramic cup 9 to be measured upside down on the lower support 4;

[0072] The metal cover 2 is connected to the metal shell 1 to form an internal enclosed space. At this time, the lower end of the upper support 3 covers the outer peripheral side wall of the ceramic cup 9 to be measured.

[0073] Connect the coupling element 7 in the inductor or capacitor region to the corresponding interface 8 on the side wall of the cavity;

[0074] Then connect interface 8 to the port of the vector network analyzer and use the vector network analyzer to measure the Q value in the lowest resonance mode of the resonant cavity;

[0075] Based on the Q value, the magnitude of the loss tangent of the ceramic cup 9 to be tested can be determined.

[0076] In this embodiment, a resonant cavity is used to detect the loss of the ceramic cup, and the Q value of the resonant cavity is used to characterize the difference in loss among the ceramic cups. Regarding the detection method, this invention does not damage the ceramic cup, maintaining the integrity and reusability of the ceramic cup workpiece; the assembly and testing of a single ceramic cup is quick and efficient, overcoming the shortcomings of conventional ceramic loss detection, which requires damaging the ceramic cup to create a sample and has a long testing time. It eliminates the need to measure the absolute value of the ceramic cup's loss tangent; only the magnitude of the Q value of the resonant mode in this device needs to be compared. This is very useful for quickly screening ceramic cups with relatively small loss tangent values ​​from a large number of ceramic cups.

[0077] In terms of detection capabilities, the shape of the ceramic lid and ceramic holder can be changed to match various irregularly shaped ceramic cups, and the volume, area, and gap of the inductor region can be changed to adapt to different operating frequencies of ceramic cups. Simultaneously, this invention provides two methods for resonant cavity energy coupling: the probe method and the coupling plate method, enabling loss tangent detection capabilities over a wide frequency band for irregularly shaped ceramic cups.

[0078] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0079] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0080] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any at least one embodiment or example. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0081] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0082] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A reentrant resonator for ceramic cup loss measurement, characterized in that, The metal shell (1) is in a cylindrical shape, the top of the metal shell (1) is provided with an opening (11), a cavity (12) is formed inside, a metal cover (2) is connected at the opening (11) for opening or closing the opening (11); An upper support (3) and a lower support (4) are arranged in the cavity (12), the upper end of the upper support (3) is connected with the metal cover (2), the lower support (4) is arranged on the bottom of the cavity (12) and corresponds to the upper support (3) up and down, the upper support (3) and the lower support (4) are both metal materials, a gap space (5) for placing a ceramic cup (9) is formed between the upper support (3) and the lower support (4), the gap space (5) is a capacitance area; an annular space (6) between the inner side wall of the metal shell (1) and the upper support (3), or between the inner side wall of the metal shell (1) and the upper support (3) and the lower support (4) forms an inductance area, a coupling element (7) is arranged in the inductance area or the capacitance area, at least two interfaces (8) are arranged on the side wall of the cavity (12), the interfaces (8) are connected with the corresponding coupling elements (7).

2. The reentrant resonator for ceramic cup loss measurement of claim 1, wherein, The upper support (3) comprises a connecting piece (31) and a ceramic cover (32) connected to the lower end of the connecting piece (31), the lower end of the ceramic cover (32) is formed with a groove (321), the lower support (4) comprises a ceramic holder (41), the ceramic holder (41) is located in the groove (321) and forms the gap space (5) with the inner side wall of the groove (321).

3. The reentrant resonator for ceramic cup loss measurement of claim 2, wherein, The connecting piece (31) is in a cylindrical shape or an inverted circular truncated cone shape.

4. The reentrant resonator for ceramic cup loss measurement of claim 2, wherein, The ceramic holder (41) is in a circular truncated cone shape, and the groove (321) is also in a circular truncated cone shape.

5. The reentrant resonator for ceramic cup loss measurement of claim 4, wherein, The upper end of the ceramic holder (41) is formed with a step (411) extending along the entire circumference.

6. The reentrant resonator for ceramic cup loss measurement of claim 2, wherein, The center of the connecting piece (31) and the ceramic cover (32) is provided with a coaxial first through hole (311), and the center of the ceramic holder (41) is provided with a penetrating second through hole (412); The interface (8) comprises a first interface (81) arranged on the metal cover (2) and a second interface (82) arranged on the bottom of the metal shell (1); The coupling element (7) comprises a first probe (71) and a second probe (72), the first probe (71) is arranged in the first through hole (311), the lower end of the first probe (71) extends to the capacitance area, and the upper end is connected with the first interface (81); the second probe (72) is arranged in the second through hole (412), the upper end of the second probe (72) extends to the capacitance area, and the lower end is connected with the second interface (82).

7. The reentrant resonator for ceramic cup loss measurement of claim 1, wherein, The interface (8) comprises a third interface (83) and a fourth interface (84) which are arranged on the side wall of the metal shell and are symmetrically distributed left and right; the coupling element (7) comprises a first coupling sheet (73) and a second coupling sheet (74), the first coupling sheet (73) and the second coupling sheet (74) are symmetrically distributed left and right in the inductive area, the first coupling sheet (73) is connected with the third interface (83), and the second coupling sheet (74) is connected with the fourth interface (84).

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