Airtight coaxial waveguide converter

Abstract

The invention discloses an airtight coaxial waveguide converter which comprises a non-airtight coaxial connector, and the front portion of a probe of the non-airtight coaxial connector is located in a waveguide cavity of a waveguide. A medium sleeve is sleeved outside the probe; the medium sleeve is tubular, the front end is closed, and the rear end is provided with an annular outer edge; the front end surface of the annular outer edge is hermetically connected with a waveguide cavity boss of the waveguide; according to the invention, the medium sleeve is combined with the non-airtight coaxial connector, so that airtight connection with the waveguide can be realized; the front end of the medium sleeve is closed, sealing between the interior of the non-airtight coaxial connector and the waveguide cavity can be achieved, sealing between the exterior of the non-airtight coaxial connector and the waveguide cavity can be achieved by combining the annular outer edge and the waveguide cavity boss, and therefore the overall airtightness of the non-airtight coaxial connector and the waveguide cavity is guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of cavity waveguide to coaxial line conversion devices, and in particular relates to an airtight coaxial waveguide converter. Background Art

[0002] Coaxial waveguide converter is a device used to convert electromagnetic waves between waveguide and coaxial transmission line, and its application is very wide. In microwave networks with inflation requirements, the product must be able to withstand a certain air pressure and maintain pressure and seal within a specified time.

[0003] In microwave networks with gas filling requirements, coaxial waveguide converters are usually implemented in the form of airtight coaxial connectors combined with waveguides. However, the sealing joint of the airtight coaxial connector is a sintered sealing joint, which is relatively expensive. Summary of the invention

[0004] The object of the present invention is to provide an airtight coaxial waveguide converter, optimize the connection structure design, and use a non-airtight coaxial connector to achieve the connection between the waveguide and the coaxial line.

[0005] The present invention adopts the following technical solution: an airtight coaxial waveguide converter, comprising a non-airtight coaxial connector, the front part of the probe of the non-airtight coaxial connector is located in the waveguide cavity of the waveguide; The outer sleeve of the probe is provided with a dielectric sleeve; The medium sleeve is tubular, with a closed front end and a circular outer edge at the rear end; The front end surface of the annular outer edge is sealed and connected to the waveguide cavity boss of the waveguide.

[0006] Furthermore, a through hole is provided on the waveguide cavity boss and the cavity wall of the waveguide; The rear end of the waveguide cavity boss is provided with a countersink, and the front end surface of the annular outer edge is sealedly connected with the bottom connecting surface of the countersink.

[0007] Further, the sinking height of the countersunk hole is greater than the thickness of the annular outer edge; A medium fixing ring is also sleeved on the outside of the probe; The front end surface of the medium fixing ring is in contact with the rear end surface of the medium sleeve.

[0008] Furthermore, the medium fixing ring is fixedly arranged on the connecting flange of the non-airtight coaxial connector.

[0009] Furthermore, the ring width of the medium fixing ring is smaller than the ring width of the medium sleeve at the annular outer edge; A pressure ring is also provided outside the medium fixing ring; The front end surface of the pressure ring is fitted with the rear end surface of the dielectric sleeve; The rear end face of the pressure ring is fitted with the front end face of the connecting flange.

[0010] Furthermore, the pressure ring is made of metal material.

[0011] Furthermore, the inner ring surface of the pressure ring is in contact with the outer ring surface of the medium fixing ring; The outer ring surface of the pressure ring is in contact with the inner ring surface of the waveguide cavity boss.

[0012] Furthermore, the pressure ring is coaxially arranged with the probe.

[0013] Furthermore, an annular groove is provided on the bottom connecting surface of the countersunk hole, and a sealing ring is arranged in the annular groove.

[0014] Furthermore, the front end surface of the annular outer edge and the bottom connecting surface of the countersunk hole are both planes.

[0015] The beneficial effects of the present invention are as follows: the present invention can achieve an airtight connection with a waveguide by combining a dielectric sleeve with a non-airtight coaxial connector; sealing the front end of the dielectric sleeve can achieve sealing between the inside of the non-airtight coaxial connector and the waveguide cavity; combining the annular outer edge and the waveguide cavity boss can achieve sealing between the outside of the non-airtight coaxial connector and the waveguide cavity, thereby ensuring the overall airtightness of the two. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of an airtight coaxial waveguide converter according to an embodiment of the present invention; Figure 2 It is a voltage standing wave ratio test curve diagram of the airtight coaxial waveguide converter in an embodiment of the present invention; Figure 3 This is an insertion loss test curve diagram of the airtight coaxial waveguide converter in an embodiment of the present invention; Figure 4 It is a voltage standing wave ratio test curve diagram of the airtight coaxial waveguide converter in the prior art; Figure 5 This is an insertion loss test curve diagram of an airtight coaxial waveguide converter in the prior art.

[0017] Among them: 10. Non-airtight coaxial connector; 11. Medium fixing ring; 12. Connecting flange; 13. Probe; 20. waveguide; 21. waveguide cavity; 22. waveguide cavity boss; 23. annular groove; 24. waveguide flange; 30. Dielectric sleeve; 40. Pressure ring. DETAILED DESCRIPTION

[0018] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] In microwave networks with inflation requirements, products must be able to withstand a certain air pressure and be able to maintain pressure and seal within a specified time. Conventional products usually use airtight coaxial connectors to achieve this. Airtight coaxial connectors are made by sintering glass insulators and metals. The process is relatively expensive, usually costing several hundred yuan, and due to the addition of glass insulators, the impedance matching performance of this product is average from the perspective of microwave characteristics.

[0020] The present invention discloses an airtight coaxial waveguide converter, such as Figure 1 As shown, the figure uses a half-section form to show the main structure of the airtight coaxial waveguide converter. Specifically, it includes a non-airtight coaxial connector 10, and the front part of the probe 13 of the non-airtight coaxial connector 10 is located in the waveguide cavity 21 of the waveguide 20. The main purpose of using the non-airtight coaxial connector 10 is to replace the airtight coaxial connector, thereby reducing the cost of the connecting parts. In the existing market, the selling price of the airtight coaxial connector is much higher than that of the non-airtight coaxial connector 10. Therefore, if the non-airtight coaxial connector 10 can be used to replace the airtight coaxial connector, the cost of the product will be greatly reduced.

[0021] However, it is difficult to meet the requirements of airtight scenarios by only using the non-airtight coaxial connector 10, so a dielectric sleeve 30 is provided on the outside of the probe 13. The dielectric sleeve 30 is tubular, with a closed front end and an annular outer edge at the rear end; the front end surface of the annular outer edge is sealed and connected to the waveguide cavity boss 22 of the waveguide 20. The dielectric sleeve 30 is made of non-metallic material, such as polytetrafluoroethylene, so that the dielectric sleeve 30 can avoid affecting the electrical performance of the airtight coaxial waveguide converter.

[0022] It should be noted that the forward direction in the present invention refers to the direction from the non-airtight coaxial connector 10 to the waveguide cavity 21, and the front end face refers to the end face closer to the waveguide cavity 21. The backward direction refers to the direction from the waveguide cavity 21 to the non-airtight coaxial connector 10, and the rear end face refers to the end face away from the waveguide cavity 21.

[0023] The present invention can achieve an airtight connection with the waveguide 20 by combining the dielectric sleeve 30 with the non-airtight coaxial connector 10; the front end of the dielectric sleeve 30 is closed to achieve sealing between the inside of the non-airtight coaxial connector 10 and the waveguide cavity 21, and the annular outer edge and the waveguide cavity boss 22 can be combined to achieve sealing between the outside of the non-airtight coaxial connector 10 and the waveguide cavity 21, thereby ensuring the overall airtightness of the two.

[0024] Preferably, the dielectric sleeve 30 is in the shape of a round tube, so that it can match the conventional interfaces of most types of waveguides 20. Of course, when the interface of the waveguide 20 is a special shape, the outer surface of the dielectric sleeve 30 needs to be matched with the interface of the waveguide 20 in shape.

[0025] The annular outer edge is formed by radially extending outward along the circumference of the cylindrical medium sleeve 30, and can be matched with the countersunk hole for easy installation. The processing method of the annular outer edge is not limited here, and it can be integrally formed with the medium sleeve 30, or the two parts can be connected after processing.

[0026] In one embodiment, the front end surface of the annular outer edge and the bottom connecting surface of the countersunk hole are both planes. Through the plane design, the contact area of ​​the two connecting surfaces can be made larger and the processing difficulty is reduced. An annular groove 23 is opened on the bottom connecting surface of the countersunk hole, and a sealing ring is arranged in the annular groove 23.

[0027] Usually, the waveguide cavity boss 22 is in the shape of a flange, and a through hole is provided on the cavity wall of the waveguide cavity boss 22 and the waveguide 20 for the probe 13 to pass through. In the present invention, in order to match the dielectric sleeve 30, the through hole is changed into a countersunk hole, which is convenient for installing the dielectric sleeve 30. That is, the rear end of the waveguide cavity boss 22 has a countersunk hole, and the front end surface of the annular outer edge is sealed and connected to the bottom connecting surface of the countersunk hole. At the same time, the connection part of the waveguide cavity 21 is provided with a waveguide flange 24, which is used to connect with other components.

[0028] In addition, the thickness of the waveguide cavity boss 22 is relatively large, which can meet the requirement of opening the annular groove 23 on the bottom connection surface of the countersunk hole. By adding a sealing ring, the air tightness between the annular outer edge and the bottom connection surface can be further increased.

[0029] In the embodiment of the present invention, the sinking height of the countersunk hole is greater than the thickness of the annular outer edge. Specifically, the sinking height refers to the height between the rear end surface of the waveguide cavity boss 22 and the bottom connecting surface.

[0030] The probe 13 is also sleeved with a dielectric fixing ring 11. A certain height difference is formed by the sinking height and the thickness of the annular outer edge. The space created by the height difference is used to accommodate the dielectric fixing ring 11. The front end surface of the dielectric fixing ring 11 fits with the rear end surface of the dielectric sleeve 30.

[0031] In the non-airtight coaxial connector 10, the probe 13 is in the shape of a thin strip, one end of which is connected to the inside of the non-airtight coaxial connector 10, and the other end extends into the waveguide cavity 21 to achieve signal transmission. However, the thin strip-shaped probe 13 has poor stability and may cause axial deviation, so the dielectric fixing ring 11 is used to increase the stability of the probe 13.

[0032] Specifically, the dielectric fixing ring 11 is fixedly arranged on the connection flange 12 of the non-airtight coaxial connector 10. In this way, the probe 13 has three fixed parts, namely, the front end is supported and fixed by the dielectric sleeve 30, the middle part is supported and fixed by the dielectric fixing ring 11, and the rear end is supported and fixed by the internal parts of the non-airtight coaxial connector 10.

[0033] Similarly, in order to prevent the dielectric fixing ring 11 from affecting the electrical performance of the airtight coaxial waveguide converter, it is also made of non-metallic materials, such as polytetrafluoroethylene.

[0034] In one embodiment, the ring width of the medium fixing ring 11 is smaller than the ring width of the annular outer edge of the medium sleeve 30; a pressure ring 40 is also provided on the outside of the medium fixing ring 11; the front end face of the pressure ring 40 is in contact with the rear end face of the medium sleeve 30; the rear end face of the pressure ring 40 is in contact with the front end face of the connecting flange 12.

[0035] In the present invention, the ring width refers to the difference between the outer radius and the inner radius of the ring body. By adding the pressure ring 40, the direct force-bearing area of ​​the outer edge of the ring can be increased, thereby increasing the pressure on the outer edge of the ring and improving the airtightness between the outer edge of the ring and the bottom connection surface. In addition, since the pressure ring 40 is located outside the medium fixing ring 11, it can be considered that the pressure ring 40 is directly pressed on the outer edge of the ring.

[0036] When the medium fixing ring 11 applies pressure to the rear end face of the medium sleeve 30, since the ring width of the medium fixing ring 11 is smaller than the ring width of the medium sleeve 30 at the annular outer edge, only the annular outer edge close to the inner ring is under pressure, and the annular outer edge close to the outer ring is not under pressure. At the same time, any workpiece has elastic strain, so when the annular outer edge close to the inner ring is under pressure, the annular outer edge close to the inner ring and close to the outer ring will produce different strains, which will cause the contact area between the annular outer edge and the bottom connection surface to become smaller, reducing the air tightness. By adding a pressure ring 40, the annular outer edge close to the inner ring and close to the outer ring can produce the same strain, so the contact area between the annular outer edge and the bottom connection surface will not become smaller, thereby maintaining the air tightness of the overall structure.

[0037] In the present invention, due to the addition of components such as the dielectric sleeve 30, the shape and size of the waveguide cavity boss 22 will be slightly adjusted, which will inevitably bring about changes in the electrical performance of the airtight coaxial waveguide converter. Therefore, the pressure ring 40 is made of metal material, which can adjust the electrical performance of the overall structure to ensure that the electrical performance of the overall structure does not change. The pressure ring 40 is used to match the impedance characteristics of the coaxial line formed by the dielectric sleeve 30 and the non-airtight coaxial connector 10, so that the airtight coaxial waveguide converter of the present invention obtains a lower voltage standing wave ratio.

[0038] More specifically, the inner surface of the pressure ring 40 fits with the outer surface of the dielectric fixing ring 11; the outer surface of the pressure ring 40 fits with the inner surface of the waveguide cavity boss 22. By setting it in this way, the space in the counterbore can be filled, which can further improve the overall air tightness on the one hand, and avoid the structural deformation of each component caused by the existence of the gap on the other hand, thereby improving the service life of the product.

[0039] In addition, since the electrical performance of the airtight coaxial waveguide converter is adjusted by the pressure ring 40 , the pressure ring 40 and the probe 13 may be coaxially arranged for convenience of calculation.

[0040] Based on the above content, the present invention can cover the application of airtight products of BJ14~BJ140 waveguide types.

[0041] In addition, the airtight coaxial waveguide converter of the present invention and the airtight coaxial waveguide converter in the prior art were tested. The JN (m) -50KFD airtight coaxial converter and BJ40 waveguide in the prior art were used as controls during the test. The N-50KFD87 non-airtight coaxial connector 10 and BJ40 waveguide were used in the technical solution of the present invention. The pressure ring 40 was made of HPb59-1 copper material.

[0042] The cost of the non-airtight coaxial connector 10 in the embodiment of the present invention is 50 yuan / piece, the cost of the dielectric sleeve 30 is 3.5 yuan / piece, the cost of the pressure ring 40 is 2.5 yuan / piece, and the comprehensive cost is 56 yuan / piece. The cost of the airtight coaxial connector in the prior art is 269 yuan / piece. It can be seen that the cost of the airtight coaxial waveguide converter in the embodiment of the present invention is much lower than the cost of the airtight coaxial connector in the prior art.

[0043] Table 1

[0044] The test method is to connect the waveguide ports of two identical products for testing.

[0045] like Figure 2 As shown in the figure, it is a voltage standing wave ratio test curve of the airtight coaxial waveguide converter of the embodiment of the present invention. The horizontal axis in the figure represents the frequency, and the vertical axis represents the voltage standing wave ratio. It can be seen from the figure that the maximum value of the voltage standing wave ratio in the full frequency band of BJ40 waveguide within the range of 3.22 to 4.90 GHz is 1.124. Figure 3 As shown, it is an insertion loss test curve chart of the airtight coaxial waveguide converter of the embodiment of the present invention. The horizontal axis in the figure represents the frequency, and the vertical axis represents the insertion loss. It can be seen from the figure that the maximum insertion loss in the full-band range of 3.22 to 4.90 GHz of the BJ40 waveguide is 0.275 dB.

[0046] like Figure 4 As shown in the figure, it is a test curve of the voltage standing wave ratio of the airtight coaxial waveguide converter in the prior art. The horizontal axis in the figure represents the frequency, and the vertical axis represents the voltage standing wave ratio. It can be seen from the figure that the maximum value of the voltage standing wave ratio in the full frequency band of BJ40 waveguide within the range of 3.22 to 4.90 GHz is 1.213. Figure 5As shown, it is an insertion loss test curve of the airtight coaxial waveguide converter in the prior art. The horizontal axis in the figure represents the frequency and the vertical axis represents the insertion loss. It can be seen from the figure that the maximum insertion loss in the full-band 3.22-4.90GHz range of the BJ40 waveguide is 0.236dB.

[0047] The specific test data are shown in Table 1, where the serial numbers in the first column of the table represent the test serial numbers; the test frequencies in the second column of the table represent the frequencies during the test, wherein the frequency range of 3.22 to 4.90 GHZ is divided into ten small frequency bands, and the corresponding eleven frequency points are taken for sampling of voltage standing wave ratio and insertion loss data; the third column of the table represents the voltage standing wave ratio measured using the airtight coaxial waveguide converter of the prior art; the fourth column of the table represents the voltage standing wave ratio measured using the airtight coaxial waveguide converter of the embodiment of the present invention; the fifth column of the table represents the insertion loss measured using the airtight coaxial waveguide converter of the prior art; and the sixth column of the table represents the insertion loss measured using the airtight coaxial waveguide converter of the embodiment of the present invention.

[0048] It can be seen that the performance parameters of the airtight coaxial waveguide converter in the embodiment of the present invention are basically consistent with those of the airtight coaxial waveguide converter in the prior art under the condition of greatly reduced cost, and even significantly better than the airtight coaxial waveguide converter in the prior art in terms of voltage standing wave ratio performance parameters. This is because the coaxial connector in the present invention uses a non-airtight coaxial connector 10, which has a simple structure and good performance. The JN (m) -50KFD type airtight coaxial connector is made of glass sintered insulators, and its performance is slightly worse than that of the non-airtight coaxial connector 10. The non-airtight coaxial connector 10 can effectively reduce the energy of the reflected signal on the transmission line and improve the transmission efficiency of the signal.

Claims

1. An airtight coaxial waveguide converter, characterized in that: It comprises a non-airtight coaxial connector (10), wherein the front part of a probe (13) of the non-airtight coaxial connector (10) is located in a waveguide cavity (21) of a waveguide (20); The probe (13) is externally covered with a dielectric sleeve (30); The medium sleeve (30) is tubular, with a closed front end and a rear end provided with an annular outer edge; The front end surface of the annular outer edge is sealedly connected to the waveguide cavity boss (22) of the waveguide (20).

2. The airtight coaxial waveguide converter according to claim 1, characterized in that: A through hole is formed on the waveguide cavity boss (22) and the cavity wall of the waveguide (20); The rear end of the waveguide cavity boss (22) is provided with a countersunk hole, and the front end surface of the annular outer edge is sealedly connected to the bottom connecting surface of the countersunk hole.

3. The airtight coaxial waveguide converter according to claim 2, characterized in that: The sinking height of the countersunk hole is greater than the thickness of the annular outer edge; The probe (13) is also sleeved with a medium fixing ring (11) on the outside; The front end surface of the medium fixing ring (11) is in contact with the rear end surface of the medium sleeve (30).

4. The airtight coaxial waveguide converter according to claim 3, characterized in that: The medium fixing ring (11) is fixedly arranged on the connecting flange (12) of the non-airtight coaxial connector (10).

5. The airtight coaxial waveguide converter according to claim 4, characterized in that: The ring width of the medium fixing ring (11) is smaller than the ring width of the medium sleeve (30) at the annular outer edge; A pressure ring (40) is also provided outside the medium fixing ring (11); The front end surface of the pressure ring (40) is in contact with the rear end surface of the dielectric sleeve (30); The rear end surface of the pressure ring (40) is in contact with the front end surface of the connecting flange (12).

6. The airtight coaxial waveguide converter according to claim 5, characterized in that: The pressure ring (40) is made of metal material.

7. The airtight coaxial waveguide converter according to claim 6, characterized in that: The inner ring surface of the pressure ring (40) is in contact with the outer ring surface of the medium fixing ring (11); The outer annular surface of the pressure ring (40) fits with the inner annular surface of the waveguide cavity boss (22).

8. The airtight coaxial waveguide converter according to any one of claims 5 to 7, characterized in that: The pressure ring (40) is coaxially arranged with the probe (13).

9. The airtight coaxial waveguide converter according to claim 2, characterized in that: An annular groove (23) is provided on the bottom connecting surface of the countersunk hole, and a sealing ring is provided in the annular groove (23).

10. The airtight coaxial waveguide converter according to claim 9, characterized in that: The front end surface of the annular outer edge and the bottom connecting surface of the countersunk hole are both planes.

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