Non-contact high power RF connector

Abstract

The RF connector includes a first conductor and a symmetrical second conductor. Each conductor has an elongated structure of flat conductive material with a length corresponding to 1 / 4 of the nominal frequency of the signal to be coupled, with a first end connected to the coaxial connector and a second end connected to the housing. The RF connector can be switched between an on state and an off state, where in the off state the first conductor is spaced apart from the second conductor and in the on state the first conductor is in close contact with the second conductor, with the open sides of their housings oriented toward each other and the conductors facing each other.

Description

[Technical field]

[0001] The present invention relates to a coaxial RF connector system that can be connected or disconnected under load. [Background technology]

[0002] A coaxial RF connector system is disclosed in EP 3300535. This connector system can couple relatively high RF power up to several kilowatts. For connection and / or disconnection, the power supply must be switched off. When these connectors are connected or disconnected under load, arcing can occur, which can lead to serious damage to the connector. Furthermore, there are no precautions to avoid late disconnection of the center conductor due to arcing, especially during premature connection or disconnection between the center conductors during connection. A central connector contact without a shield or ground contact can pose a safety risk, as the ungrounded section of the conductor system can be at high voltage. This can be harmful to anyone operating the connector.

[0003] A 3 dB directional coupler is disclosed in US Patent No. 4,754,241. The 3 dB directional coupler includes two sets of striplines arranged in parallel, close to each other with a small gap between the striplines. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] European Patent Application Publication No. 3300535 [Patent Document 2] U.S. Pat. No. 4,754,241 Summary of the Invention [Problem to be solved by the invention]

[0005] The problem to be solved by the present invention is to provide an RF connector system that can carry high RF power in the range of several kilowatts and can safely connect and / or disconnect when an RF voltage is applied to at least one side of the connector system. [Means for solving the problem]

[0006] The solution to the problem is set forth in the independent claims. The dependent claims relate to further developments of the invention.

[0007] The connector system according to one embodiment is based on a pair of non-contact couplers. The coupler structure is similar to a 3 dB coupler with only one input and one output, and therefore functions as a zero dB coupler. The coupler may be based on stripline technology and may have a stripline with a length of λ1 / 4, which is ¼ of the wavelength of the signals to be coupled. It may also have a multiple of ¼ of the wavelength. In the connected state, the two striplines are close to each other. In the disconnected state, the striplines may be far from each other, such that there is no longer any coupling between the striplines. There may be a guide mechanism such that the connecting and disconnecting process is performed by a linear movement that shifts or displaces the two pairs relative to each other. The striplines may be bent or folded at least one or more times to reduce the size of the coupler.

[0008] In one embodiment, the RF connector includes two approximately symmetrical and / or identical coupler sections. Each coupler section may include a conductor. The housing that holds the conductors may have essentially a rectangular parallelepiped shape that may have open sides and form an open cavity with the shape of an elongated channel for the conductors. The shape of the housing may be relatively flat. Typical dimensions may be length and width in the range of 20 mm to 300 mm. The height of the housing may be between 3 mm and 50 mm. The dimensions of the housing are determined by the conductors within the housing, which may have a length corresponding to 1 / 4 of the nominal frequency of the signals to be coupled. Each conductor has an elongated structure of flat conductive material. It may include a strip of copper or brass, or even aluminum, which may be further coated on its outer surface with a conductive material, for example silver or gold. The conductors may have a width in the range of 1 / 100 to 1 / 5 of their length and a thickness in the range of 0.5 mm to 5 mm. The conductors may be wider than their thickness. The conductors may be placed in the open cavity of the housing and may be recessed relative to the outer surface of the housing. The conductor may therefore not protrude from the surface of the housing. The conductor may be connected at a first end to a coaxial connector to provide an electrical contact. Instead of a connector, a further stripline or any kind of waveguide may be provided. The conductor may be connected to the housing at a second end opposite the first end. This may in particular be connected to a side wall of the housing.

[0009] RF connectors are essentially intended to have the function of a switch and therefore may be considered as switching couplers. They may be switched between an on state and an off state. In the off state, the first and second conductors are separated. Separate means that the conductors of the two opposing conductors do not overlap, but the edges of the housings may touch. To achieve higher isolation, the conductors may be separated from each other without touching each other.

[0010] In the on state, the first conductor is in close contact and / or proximity to the second conductor.

[0011] In embodiments with separate housings for each conductor, the open sides of the housings may be oriented opposite one another and may overlap, which may form a common cavity between the two housings with the conductors facing one another, preferably across their entire length and / or width.

[0012] Typically, the conductors do not touch each other. They may, for example, be recessed relative to the surface of the housing. These closely opposed conductors provide a non-galvanic coupling to the RF signal in the on-state. In contrast, in the off-state, each conductor is a λ / 4 transformer that provides a virtual open circuit to its coaxial connector.

[0013] In one embodiment, the conductors may be disposed in separate planes such that the planes are parallel in the on-state. The conductors may be mirror symmetric with respect to a plane of symmetry between the planes of the conductors. The plane of symmetry may be parallel to the planes of the conductors.

[0014] In one embodiment, the conductor has a curved shape. Such curved shapes can include angles, bends, and edges.

[0015] In one embodiment, in the on state, the conductors may be essentially a fixed distance apart, so that the conductors may not be able to contact and maintain galvanic isolation between them, and the conductors may have slightly varying distances due to manufacturing tolerances or due to slight bending to optimize coupling characteristics.

[0016] In one embodiment, in the on state, the conductors may be separated by a distance less than 1 / 10 of the nominal wavelength of the signals being coupled.

[0017] A mechanical support structure may further be provided to guide the movement of the conductors between the on and off states to perform the appropriate switching functions. This may be a linear guide system, which may include linear rails or similar guide structures. Additionally, the mechanical support structure may provide a means to hold the conductors in either the on and / or off states.

[0018] In one embodiment, each coupler section may be housed in a housing. Each housing may hold a conductor. Further, each housing may have a rectangular parallelepiped shape with open sides forming an open channel such that each conductor may be placed in the open channel. In the on state, the open sides of the housings are oriented opposite one another.

[0019] In another embodiment, both coupler sections, and therefore both conductors, are housed in a common housing that holds both conductors, where at least one of the conductors is movable within the housing relative to the other conductor. The housing may be completely closed with only two coaxial connectors for connecting the conductors. In another embodiment, the housing may have one or two open sides, such that it may have the shape of a rectangular waveguide.

[0020] The first conductor may be movable relative to the second conductor. Here, the mechanical support structure may include at least one groove, guide rail or (linear) bearing for guiding the first conductor. An actuator for moving the first conductor may further be provided.

[0021] Further, a shorting element may be provided in an off position of at least one conductor. The off position is a position where the conductor is in an off state. The shorting element may be configured to provide a capacitive coupling between at least one conductor and at least one housing. There may be multiple shorting elements that may be arranged closely adjacent to multiple sections of the conductor (e.g., a U-shaped conductor, or a more complex conductor). At least one further shorting element may be arranged parallel to at least one further straight section of the conductor so as to be adjacent to the straight section in the off position. Any of the shorting elements may have a dielectric surface coating, which may include an oxide layer, a powder coating, a paint coating, or a plastic material.

[0022] In another embodiment, a shorting contact may be provided that provides galvanic contact between the conductor and ground in the off position. This contact may be spring loaded. It may be configured to only contact the conductor in the final off position and not during movement between the conductors. This allows for a switching process without a galvanic contact, which is only a safety feature.

[0023] In one embodiment, the conductors are arranged to be slidable laterally relative to each other on the plane of at least one of the open sides. Both open sides may be coplanar. This provides a well-defined transition between the on and off states. Basically, the conductors may be movable in either direction, as long as they are close together in the on state and far apart in the off state. Alternatively, the conductors may be rotated relative to each other. The on position may be when they overlap in the same orientation, and the off position may be at an angle of, for example, 90 degrees or 180 degrees.

[0024] In another embodiment, each conductor has a U-shape. Such a U-shape may include a first straight section and a second straight section parallel to the first straight section. The straight sections may be interconnected by a transverse section. The U-shape is beneficial because it reduces the overall length of the coupler. The U-shape is essentially a two-fold bent coupler. In further embodiments, the coupler may have a non-bent linear structure or may have multiple bends, such as three or four or more bends. A larger number of bends further reduces the size, which may be beneficial for lower frequencies.

[0025] In one embodiment, the conductor is slidably positioned perpendicular to the straight section. Such vertical movement provides a very smooth transition without electric field peaks that can result in arching during switching of high power levels.

[0026] In one embodiment, a sealing strip and / or gasket may be provided on the open side of the housing or at least one of the coupler sections, or both coupler sections, to improve electrical contact between the coupler sections.

[0027] In one embodiment, at least one matching plate or structure may be provided between the housing and the conductors of the coupler section. Such a matching plate may be adjustable in distance to the conductors. It may comprise either a dielectric material or a conductive material electrically connected to the housing. Such a matching plate may be used to adjust the impedance of the conductors and / or their frequency response.

[0028] In one embodiment, at least one adjustment rod is provided, which may be configured to bend at least one conductor to change the distance between the conductors. This may help optimize the structure and compensate for manufacturing tolerances. The at least one adjustment rod may include a dielectric material. It may further include an external thread that matches a threaded hole in the housing. The invention will now be described by way of example, without limiting the general inventive concept, with reference to the drawings, on examples of embodiments. [Brief description of the drawings]

[0029] [Figure 1] FIG. 2 shows a coupler section of the first embodiment. [Diagram 2] FIG. 2 shows a complete RF connector. [Diagram 3] 1 is a side view of the first and second coupler sections in a mated state; FIG. [Figure 4] FIG. 1 shows the basic topology of a two-fold coupler. [Diagram 5] FIG. 1 discloses a single line combiner. [Figure 6] FIG. 1 illustrates a three-fold coupler. [Figure 7] FIG. 1 shows a four-fold combiner. [Figure 8] FIG. 13 illustrates a second embodiment in an off state. [Figure 9] FIG. 13 illustrates a second embodiment in an on state. [Figure 10] FIG. 11 is a side view of the second embodiment. [Figure 11] FIG. 1 shows the basic topology of a two-fold coupler. [Figure 12] FIG. 1 discloses a single line combiner. [Figure 13] FIG. 1 illustrates a three-fold combiner. [Figure 14] FIG. 1 shows a four-fold combiner. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] 1 to 7 relate to a first embodiment.

[0031] In FIG. 1, a coupler section 200 is shown. In a complete connector, two preferably identical sections are arranged symmetrically. The first coupler section 200 will now be described in detail. The coupler section 200 includes a housing 210 that holds a conductor 220. The conductor is in an open cavity 212 slightly recessed below the surface of the housing 210 so as not to protrude outside the housing. The housing may be solid metal or any other suitable conductive material and forms the cavity 212 for the conductor. In the embodiment shown in this figure, the cavity 212 has a U-shape for holding a U-shaped conductor. This U-shape is chosen to reduce the length of the housing. Thus, the conductor has a first straight section 222 and a second straight section 224 joined by a transverse section 223. The transverse section 223 may have a chamfered edge to minimize reflections. The conductor 220 has an overall length including the first straight section 222, the transverse section 223 and the second straight section 224. All sections have an overall length of approximately 1 / 4 or a multiple of 1 / 4 of the wavelength of the signal being transmitted. The conductor 220 has a short at one end 228 that connects to the section housing 210. At the opposite end it has a connector section 221 that can be connected to a coaxial connector 240.

[0032] Additionally, matching components may be provided, such as a first matching plate 231 and / or a second matching plate 233. These matching plates are optional and may be adjusted so that the coupler provides a desired impedance, such as 50 ohms, in the desired frequency range. The coupler may be designed for any operating frequency ranging from 10 megahertz to 10 gigahertz. The conductor lengths must be matched accordingly. The relative operating bandwidth may be 2% to 20% of the nominal bandwidth for which the conductor lengths are designed.

[0033] FIG. 2 shows a complete RF connector 100 including a first coupler section 200 and a second coupler section 300. The internal structure of the first coupler section 200 and the second coupler section 300 is the same. Thus, they have the same cavity 212, the same conductors 220, and they may have the same alignment plates 231, 233. Both couplers may be mechanically coupled by a housing (not shown), or by a guide system, or by any other suitable coupling means. Here, for example, a first guide rail 170 and a second guide rail 180 are shown. The guide rails may be essentially the same. Here, the second guide rail 180 has a first guide slot 182 and a second guide slot 184. The first guide rail 170 may have identical slots. Additionally, the second coupler section 300 may have a pair of pins including a first guide pin 382 that may be guided by the first guide slot 182 and a second guide pin 384 that may be guided by the second guide slot 184. This pin and slot mechanism allows the second coupler section 300 to slide in the direction 190 over the first coupler section toward the first coupler section, where the second coupler section 300 may completely cover the first coupler section. In the illustrated configuration, the first coupler section 200 and the second coupler section 300 are spaced apart from each other such that there is no coupling between these coupler sections. After the second coupler section 300 moves in the direction 190 over the first coupler section 200 to completely cover the first coupler section 200, there is good coupling with very low coupling loss.

[0034] This RF connector 100 is symmetrical so that the coaxial connector of either the first coupler section 200 or the second coupler section 300 may be used as an input and the other as an output.

[0035] With this configuration, essentially two different states are possible: an on state, where the coupler sections cover each other, and an off state, where the coupler sections are apart. This can be used to switch signals and / or RF power. Since the coupling does not involve galvanic contact, switching also does not involve interruption of mechanical contact. Thus, there is no contact and no arcing. Furthermore, the connection has very low passive intermodulation.

[0036] FIG. 3 shows a side view of the first coupler section 200 and the second coupler section 300 in a mated state, with the coupler sections overlaying each other. Here, due to the symmetrical arrangement, it is shown that there is a short at the short end 228 of the conductor 220 of the first coupler section 200 above the location of the second coaxial connector 340 of the second coupler section 300. In addition, the conductor 220 of the first coupler section 200 is shown slightly spaced from the conductor 320 of the second coupler section 300. Due to the recessed location of the conductor in the cavity, a gap remains between the conductors. This results in a non-contact coupling between the coupler sections. Here, the coupler sections are held by the housing 110, which can slide them against each other. The matching plate can have a support, such as support 234, on the matching plate 233. This support can allow height adjustment to move the matching plate closer or further away from the conductor 220. The support 234 can include a dielectric material. It may further include a screw thread.

[0037] Additionally, at least one adjustment rod may be included, such as a first adjustment rod 235 in the first conductor 220 and a second adjustment rod 236 in the second conductor 320. There may be multiple adjustment rods. The adjustment rod may be configured to bend at least one of the conductors to change the distance between the conductors.

[0038] FIG. 4 shows generally the basic topology of a two-fold combiner 420, as described above.

[0039] In Figure 5, a single line coupler 410 is a variation of the two-fold coupler 420 shown above, but is based on the same coupling principle. Such couplers may be used with shorter wavelengths corresponding to higher frequencies, without necessarily folding the line to reduce the coupler length.

[0040] 6 shows a three-fold combiner 430, where the line is folded into three sections, which allows for further reduction in space, especially for lower frequencies.

[0041] FIG. 7 shows the basic concept of a four-fold combiner 440, similar to the combiners shown previously, but with the lines folded four times to further reduce the size of the combiner.

[0042] 8 to 14 relate to a second embodiment which is very similar to the first embodiment and only the differences will be described.

[0043] In FIG. 8, the second embodiment is shown in an off state. In this embodiment, a first coupler section 200, a symmetrical second coupler section 300 are held in a common housing 510. To switch between an off state and an on state, at least one of the coupler sections is moved relative to the other coupler section within the common housing. In the off state shown in this figure, the first coupler section 200 is displaced, e.g., upwards, such that the first conductor 220 of the first coupler section 200 is separated from the second conductor 320 of the second coupler section 300, e.g., not overlapping. Furthermore, at least one of the conductors may be close to a shorting element 230 such that there is a capacitive coupling between the common housing 510 and at least one of the conductors via the shorting element 230. There may be multiple shorting elements that may be placed in close proximity to multiple sections, which may be straight sections of conductors in the off state position.

[0044] The first conductor 220 includes a first straight section 222, a transverse section 223, and a second straight section 224. All sections have an overall length of approximately ¼ or a multiple of ¼ of the wavelength of the signal being transmitted. The first conductor 220 has a short at a short end 228 with the housing 510. At the opposite end, it has a connector section 221 that can be connected to a coaxial connector 240.

[0045] To operate the switch, the first conductor 220 may be movable relative to the second conductor 320. As long as such relative movement is provided, it does not matter which conductor is actually moved and which conductor is in a fixed position. Both conductors may be moved simultaneously.

[0046] To allow the first conductor 220 to move relative to the fixed second conductor 320, the connector section 221 may include a telescopic line, which may be variable in length. Such a telescopic line may have a first circular conductor slidably located within a larger second circular conductor. There may be a radial contact spring between the first and second circular conductors. The telescopic line may also include two flat conductors slidable relative to each other, which may be in galvanic or capacitive contact. Furthermore, a sliding contact 239 may be provided at the shorting end 228 of the first conductor 220 for shorting connection to the housing 510. The sliding contact may include at least one contact spring, which may include a contact material such as brass or steel or any other suitable material, and may have a conductive surface, which may include a contact material such as silver or gold.

[0047] The first conductor 220 may have a support by a guide block 237, which may have means for slidably guiding the first conductor 220. The guide block 237 may have a groove in which the first conductor 220 may be slidable. The guide block 237 may further support and stabilize the second conductor 320. The guide block may include a dielectric material to prevent short circuits between the conductors and to ground. The short end 228 of the first conductor 220 may be slidably guided in the housing 510 or in a groove 238 in the housing 510. For the movement of the first conductor 220, an actuator 250 may be provided. This may be a rod of dielectric material. The actuator 250 may be capable of moving the first conductor 220, for example, in a linear motion. The actuator 250 may be operated manually or may be driven by a motor (not shown). When the motor is not moving, the motor may hold the first conductor in its actual position. The actuator may also include a gear or gear rod, or any other suitable means for effecting linear motion.

[0048] The first conductors 220 may be positioned anywhere between the OFF position shown in FIG. 8, where the conductors are spaced apart from one another, and the ON position as shown in FIG. 9, where the conductors are close together.

[0049] The second conductor 320 includes a first straight section 322, a transverse section 323, and a second straight section 324. All sections have an overall length of approximately ¼ or a multiple of ¼ of the wavelength of the signal being transmitted. The second conductor 320 has a short 328 at one end with the housing 510. At the opposite end, it has a connector section 321 that can be connected to a coaxial connector 340. The connector section 321 may be variable in length.

[0050] In Figure 9, the second embodiment is shown in an on state, in which the first coupler section 200 is adjacent to the second coupler section 300 such that the conductors 220, 320 face each other.

[0051] 10 shows a side view of the second embodiment, which shows the conductors 220, 320 facing each other in the on state, resulting in a small gap between the conductors.

[0052] Figure 11 shows, as mentioned above, a schematic of the basic topology of a two-fold coupler 520. Here, for clarity, only one conductor is shown; the second conductor is symmetrical to this. In the following, only one conductor is shown.

[0053] In Figure 12, a single line coupler 510 is a variation of the two-fold coupler 520 shown above, but is based on the same coupling principle. Such couplers may be used with shorter wavelengths corresponding to higher frequencies, without necessarily folding the line to reduce the length of the coupler.

[0054] 13 shows a three-fold combiner 530, where the line is folded into three sections, which allows for further reduction in space, especially for lower frequencies.

[0055] FIG. 14 shows the basic concept of a four-fold combiner 540, similar to the combiners shown previously, but with the lines folded four times to further reduce the size of the combiner. [Explanation of symbols]

[0056] 100 RF Connector 110 Housing 170 First guide rail 180 Second guide rail 182 First guide slot 184 Second guide slot 190 Direction of movement 200 first combiner section 210 First Section Housing 212 Cavity 220 First Conductor 221 Connector Section 222 First Straight Section 223 Transverse Section 224 Second Straight Section 228 Shorted End of Conductor 230 Shorting element 231 First matching plate 233 Second matching plate 234 Matching Plate Support 235 Adjustment rod in first conductor 236 Adjustment rod in second conductor 237 Guide Block 238 Guide groove 239 Sliding Contact 240 First coaxial connector 250 Actuator 300 Second Combiner Section 310 Second Section Housing 320 Second Conductor 321 Connector Section 322 First Straight Section 323 Transverse Section 324 Second Straight Section 328 Short Circuit 340 Second Coaxial Connector 382 First guide pin 384 Second Guide Pin 410 Single Line Combiner 420 Two-fold coupler 430 3-fold coupler 440 4-fold coupler 510 Common Housing 512 Cavity

Claims

1. An RF connector (100) comprising a first coupler section (200), a symmetrical second coupler section (300), and at least one housing (510), the first coupler section comprising a first conductor (220) and the second coupler section comprising a second conductor (320); The first conductor (220) and the second conductor (320) each include: a flat elongated structure of conductive material; recessed relative to an outer surface of the housing; having a length corresponding to ¼ or a multiple of ¼ of the nominal wavelength of the signal to be coupled; A first end is connected to a coaxial connector; a second end connected to the housing; The RF connector can be switched between an on state and an off state by moving the first conductor (220) relative to the second conductor (320); In the off state, the first conductor (220) is spaced apart from the second conductor (320); In the on-state, the first conductor (220) is adjacent to the second conductor (320), and the conductors (220, 320) face each other; the RF connector comprising a mechanical support structure for guiding the movement of the conductors between the on and off states and for retaining them in the on and / or off states. RF connector (100).

2. at least one actuator (250) is provided, said at least one actuator (250) configured to move said first conductor (220), 2. The RF connector of claim 1.

3. Both conductors are housed in a housing (510) that holds both conductors (220, 320).

3. The RF connector according to claim 1 or 2.

4. at least one capacitive shorting element (230) is provided in an off position of at least one of the conductors (220, 320) and configured to provide a capacitive coupling between the at least one conductor (220, 320) and the at least one housing (210, 310), 4. The RF connector according to claim 3.

5. at least one galvanic shorting element (230) is provided in an OFF position of at least one of the conductors (220, 320) and is configured to provide a galvanic short between the at least one conductor (220, 320) and the at least one housing (210, 310), 5. The RF connector according to claim 3 or 4.

6. said conductors (220, 320) are arranged laterally slidably and parallel to each other; and / or The conductor (220, 320) is slidably disposed perpendicular to the straight section.

6. The RF connector according to claim 1.

7. In the on state, Each of the conductors (220, 320) is disposed in a different plane; the planes of the conductors (220, 320) are parallel; the conductors (220, 320) are mirror symmetric about a plane of symmetry between the planes of the conductors (220, 320); the plane of symmetry is parallel to the plane of the conductor (220, 320); and / or The conductors (220, 320) are spaced apart by a fixed distance.

7. The RF connector according to claim 1.

8. In the on state, the conductors (220, 320) are spaced apart by a distance less than 1 / 10 of the nominal wavelength of the signals being coupled together; 8. The RF connector according to claim 1.

9. Each of the conductors (220, 320) is curved.

9. The RF connector of claim 8.

10. Each conductor (220, 320) is characterized in that it has an I-shape or a U-shape.

10. An RF connector according to claim 1.

11. Each conductor (220, 320) is a flat conductor and has a first straight section (222) and at least one second straight section (224) parallel to said first straight section (222), each straight section being interconnected to adjacent straight sections by a transverse section (223).

11. The RF connector according to claim 1.

12. characterised in that sealing strips and / or gaskets are provided on the open sides of the housing to improve electrical contact, 12. An RF connector according to claim 1.

13. a cover is provided to cover at least one open side of the coupler section in the off state; 13. An RF connector according to claim 1.

14. At least one matching plate is provided between the housing and the conductor, the at least one matching plate being adjustable in distance to the conductor and may include a dielectric material or a conductive material electrically connected to the housing.

14. An RF connector according to claim 1.

15. At least one adjustment rod is provided to bend at least one of the conductors (220, 320) to change the distance between the conductors; At least one of the adjustment rods may include a dielectric material.

15. An RF connector according to claim 1.

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