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. Power must be turned off to connect and / or disconnect. When these connectors are connected or disconnected under load, arcing can occur, leading to serious damage to the connector. Furthermore, no precautions are taken to avoid premature connection or disconnection between center conductors during connection, especially late disconnection of the center conductor due to arcing. A center connector contact without a shield or ground contact could pose a safety risk because the ungrounded section of the conductor system could be at high voltage, which could be harmful to personnel operating the connector.

[0003] A 3 dB directional coupler is disclosed in U.S. 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. Patent 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 that 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 out in the independent claims. The dependent claims relate to further refinements of the invention.

[0007] One embodiment of the connector system 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, thus functioning as a zero dB coupler. The coupler may be based on stripline technology and have striplines with a length of λ1 / 4, which is 1 / 4 of the wavelength of the signals being coupled. It may also have a length that is a multiple of 1 / 4 of the wavelength. In the connected state, the two striplines are close to each other. In the disconnected state, the striplines may be separated from each other so that there is no longer coupling between them. A guide mechanism may be present so that the connection and disconnection 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 contain a conductor. The housing holding the conductors may have a generally rectangular parallelepiped shape with open sides, forming an open cavity with the shape of an elongated channel for the conductor. 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 signal to be coupled. Each conductor has a flat, elongated structure of conductive material. This may include a strip of copper, brass, or even aluminum, which may be further coated on its outer surface with a conductive material, such as 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 disposed in the open cavity of the housing and recessed relative to the outer surface of the housing. Thus, the conductor may not protrude from the surface of the housing. The conductor may have a first end connected to a coaxial connector to provide electrical contact. Instead of a connector, a further stripline or any type 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 function as switches and can therefore be considered 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. Separated 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 or may overlap, forming a common cavity between the two housings with the conductors facing one another, preferably across their entire length and / or width.

[0012] The conductors typically 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 for the RF signal in the on-state. In contrast, in the off-state, each conductor is a λ / 4 transformer, presenting a virtual open circuit to its coaxial connector.

[0013] In one embodiment, the conductors may be arranged 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, which may include angles, bends, and edges.

[0015] In one embodiment, in the on state, the conductors may be an essentially constant distance apart, so that the conductors may not be able to contact and maintain galvanic isolation between them. The conductors may have slightly varying distances due to manufacturing tolerances or due to slight bends 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 signal being coupled.

[0017] To perform the appropriate switching function, a mechanical support structure may further be provided to guide the movement of the conductors between the on and off states. 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 open channels such that each conductor may be placed in the open channels. In the on state, the open sides of the housings are oriented opposite each other.

[0019] In another embodiment, both coupler sections, and therefore both conductors, are housed in a common housing that holds both conductors, with at least one of the conductors being 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, allowing it to 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] Additionally, a shorting element may be provided in the 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 capacitive coupling between at least one conductor and at least one housing. There may be multiple shorting elements that may be positioned closely adjacent to multiple sections of the conductor (e.g., a U-shaped conductor or a more complex conductor). At least one additional shorting element may be positioned parallel to at least one additional 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 contact the conductor only in the final off position and not during movement between the conductors. This allows for a switching process without a galvanic contact, although the galvanic contact is only a safety feature.

[0023] In one embodiment, the conductors are arranged to slide 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. Essentially, 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 are overlapping in the same orientation, and the off position may be at an angle of, for example, 90 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 transverse sections. The U-shape is beneficial because it reduces the overall length of the coupler. The U-shape is essentially a two-fold bend coupler. In further embodiments, the coupler may have a non-bend 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 field peaks that can result in arching during switching at 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, and the adjustment rod can be configured to bend at least one conductor to change the distance between the conductors. This can help optimize the structure and compensate for manufacturing tolerances. The at least one adjustment rod can include a dielectric material. It can further include an external thread that mates with a threaded hole in the housing. The invention will now be described by way of example, without limiting the general inventive concept, on example embodiments with reference to the drawings, in which: FIG. [Brief explanation of the drawings]

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

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

[0031] Figure 1 shows a coupler section 200. A complete connector has two, preferably identical, sections 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 resides in an open cavity 212 slightly recessed below the surface of the housing 210 so that the conductor does not protrude outside the housing. The housing, which may be solid metal or any other suitable conductive material, forms the cavity 212 for the conductor. In the embodiment shown in this figure, the cavity 212 has a U-shape to hold the conductor. This U-shape was selected 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. Conductor 220 has a short at one end 228 that connects to section housing 210. At the opposite end is connector section 221 that can be connected to 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 can be adjusted so that the coupler provides a desired impedance, such as 50 ohms, in the desired frequency range. The coupler can 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 the complete RF connector 100, including a first coupler section 200 and a second coupler section 300. The first coupler section 200 and the second coupler section 300 have the same internal structure. Therefore, they may have the same cavity 212, the same conductor 220, and the same alignment plates 231 and 233. Both couplers may be mechanically coupled by a housing (not shown), a guide system, or 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 identical. 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 can be guided by the first guide slot 182 and a second guide pin 384 that can be guided by the second guide slot 184. This pin and slot mechanism allows the second coupler section 300 to slide in direction 190 over the first coupler section toward the first coupler section, so that the second coupler section 300 can 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 so that there is no coupling between these coupler sections. After the second coupler section 300 is moved in 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] Because this RF connector 100 is symmetrical, 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] This configuration allows for two different states: an on state, where the coupler sections overlap each other, and an off state, where the coupler sections are separated. This can be used to switch signals and / or RF power. Because coupling does not involve galvanic contact, switching also does not involve interruption of mechanical contact. Therefore, there is no contact or 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 overlapping each other. Due to the symmetrical arrangement, a short circuit is shown at the shorted end 228 of the conductor 220 of the first coupler section 200, located above the location of the second coaxial connector 340 of the second coupler section 300. Furthermore, the conductor 220 of the first coupler section 200 is shown slightly spaced apart from the conductor 320 of the second coupler section 300. Due to the recessed position 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 allows them to slide relative to each other. The matching plate may have supports, such as support 234, on the matching plate 233. This support may allow height adjustment to move the matching plate closer to or farther from the conductor 220. The support 234 may 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 a schematic of the basic topology of a two-fold combiner 420, as described above.

[0039] 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 at 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] Figures 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 the off state. In this embodiment, the first coupler section 200 and the symmetrical second coupler section 300 are held in a common housing 510. To switch between the off state and the on state, at least one of the coupler sections is moved relative to the other coupler sections within the common housing. In the off state shown in this figure, the first coupler section 200 is displaced upward, e.g., so that the first conductor 220 of the first coupler section 200 is spaced apart from the second conductor 320 of the second coupler section 300, e.g., so that they do not overlap. Furthermore, at least one of the conductors may be near the shorting element 230 such that capacitive coupling exists between the common housing 510 and at least one of the conductors via the shorting element 230. There may be multiple shorting elements positioned adjacent 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 a total length of approximately 1 / 4 or a multiple of 1 / 4 of the wavelength of the signal being transmitted. The first conductor 220 has a short at end 228 with the housing 510. At the opposite end is 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 telescoping line, which may be variable in length. Such a telescoping 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 telescoping line may also include two flat conductors that are slidable relative to each other, which may be in galvanic or capacitive contact. Additionally, a sliding contact 239 may be provided at the shorting end 228 of the first conductor 220 for short-circuiting connection to the housing 510. The sliding contact may include at least one contact spring that may include a contact material such as brass or steel or any other suitable material and have a conductive surface that may include a contact material such as silver or gold.

[0047] The first conductor 220 may be supported by a guide block 237, which may have a means for slidably guiding the first conductor 220. The guide block 237 may have a groove in which the first conductor 220 can slide. 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 conductors and to ground. The short-circuit end 228 of the first conductor 220 may be slidably guided in the housing 510 or in the groove 238 within the housing 510. An actuator 250 may be provided for movement of the first conductor 220. 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 manually operated or 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, 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 a total length of approximately ¼ or a multiple of ¼ of the wavelength of the signal being transmitted. The second conductor 320 has a short circuit 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 of variable length.

[0050] In Figure 9, the second embodiment is shown in the 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] Figure 10 shows a side view of the second embodiment, showing the conductors 220, 320 facing each other in the on state, resulting in a small gap between the conductors.

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

[0053] 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 at shorter wavelengths corresponding to higher frequencies, and do not necessarily require folding the line to reduce the coupler length.

[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 combiner 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 Short-circuit element 231 First matching plate 233 Second matching plate 234 Alignment plate support 235 Adjusting rod in first conductor 236 Adjusting 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 Cross Section 324 Second Straight Section 328 Short Circuit 340 Second Coaxial Connector 382 First guide pin 384 Second guide pin 410 Single Line Coupler 420 Two-fold coupler 430 Tri-fold Coupler 440 4-fold coupler 510 Common Housing 512 cavity

Claims

1. An RF connector (100) comprising a first coupler section (200), a second coupler section (300), and at least one housing (510) formed of a conductive material, wherein the first coupler section comprises a first conductor (220), and the second coupler section comprises a second conductor (320); The first conductor (220) and the second conductor (320) each comprise: a flat elongated structure of conductive material; disposed within an open cavity (212) recessed relative to an outer surface of the at least one housing; having a length corresponding to one-quarter or a multiple of one-quarter of the nominal wavelength of the signal to be coupled; a first end connected to each coaxial connector of the RF connector; a second end connected to the at least one 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, the at least one actuator (250) being configured to move the first conductor (220) within a single housing (510).

2. The RF connector of claim 1.

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

2. The RF connector of claim 1.

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

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

6. the 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.

2. The RF connector of 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.

2. The RF connector of claim 1.

8. In the on state, the conductors (220, 320) are separated by a distance less than 1 / 10 of the nominal wavelength of the signals to be coupled; 2. The RF connector of claim 1.

9. Each of the conductors (220, 320) has a curved shape.

9. The RF connector of claim 8.

10. Each conductor (220, 320) is characterized by having an I-shape or a U-shape.

2. The RF connector of 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 the first straight section (222), each straight section being interconnected to adjacent straight sections by a transverse section (223).

2. The RF connector of claim 1.

12. characterised in that in the case of two housings (210, 310) a sealing strip and / or a gasket is provided on the open side of at least one of said housings (210, 310) to improve the electrical contact, 2. The RF connector of claim 1.

13. In the case of two housings (210, 310), a cover is provided to cover at least one open side of the coupler section in the off state.

2. The RF connector of 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.

2. The RF connector of 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.

2. The RF connector of claim 1.

Images