A slip ring wireless transmission structure for X-ray computed tomography equipment

Abstract

The application relates to a slip ring wireless transmission structure applied to an X-ray tomography device, which comprises a transmitting antenna and a receiving antenna, wherein the transmitting antenna is composed of a transmitting transmission line and a transmitting switching plate, the transmitting antenna is arranged on the radial outer side of the slip ring, and the receiving antenna is fixed on a device rack; through optimized design of the structure of the matched end of the transmitting antenna, the transmitting switching plate and the receiving antenna, and use of a periodic structure microstrip line in the transmitting transmission line, compared with the existing wireless transmission structure of the device, the near-field coupling efficiency is improved, meanwhile, the system return loss is effectively improved, the signal-to-noise ratio is reduced, the transmission stability and reliability are effectively improved, and the use requirement of the CT device can be better met.

Description

Technical Field

[0001] This invention relates to the field of rotary connector technology, and more specifically to a slip ring wireless transmission structure for use in X-ray computed tomography equipment. Background Technology

[0002] Computed Tomography (CT) is a medical imaging technique that uses X-ray beams to perform tomographic scanning of the human body and then uses a computer to process the data to produce detailed images of the body's internal structures. During CT operation, the X-ray tube and detectors rotate around the patient to acquire image data from different angles. This process requires transmitting data detected by the X-ray detectors from the rotating part to the stationary part for further processing by the main unit to generate image data. Therefore, a large amount of data needs to be transmitted in a short period of time.

[0003] Most current computed tomography (CT) equipment uses slip rings to achieve data transmission between rotating and stationary parts. In traditional conductive slip rings, the stator and rotor are connected by brushes and slip rings, respectively. Due to the relative motion characteristics between the slip ring and the stator, low-speed control signals can be transmitted through contact between the brushes and the slip ring. However, for high-speed data streams, non-contact near-field coupling (i.e., wireless transmission) is mainly used to transmit the data signals on the rotating slip ring to the fixed receiving device.

[0004] A non-contact slip ring data transmission system typically includes a transmitting unit on a rotating part and a receiving unit on a stationary part. The transmitting unit has a transmitting antenna connected to a transmitter and is arranged around the periphery of the rotating part of the rotating frame. The receiving unit includes a receiver and a receiving antenna connected to the receiver. During the operation of a computed tomography (CT) machine, the transmitting antenna moves past the receiving antenna at a small distance, allowing the signal propagating on the transmitting antenna to be input to the receiving antenna via near-field coupling.

[0005] In existing slip-ring wireless transmission, both domestic and international manufacturers implement wireless transmission at speeds below 10Gbps using differential transmission lines (transmitting antennas) and differential microstrip lines (receiving antennas) with terminal matching. A differential transmission line mainly consists of a pair of microstrip lines and a terminal matching structure. Microstrip lines offer wide bandwidth and high transmission speed, giving them unique advantages in high-frequency applications. However, they suffer from significant transmission loss and high far-end crosstalk, posing challenges in impedance control, crosstalk, and loss management, thus limiting improvements in antenna transmission performance. Furthermore, existing differential microstrip line terminal matching structures primarily employ coplanar waveguide structures and resistors for matching. Coplanar waveguide matching is highly sensitive to the size of the gaps on both sides. Limited by PCB manufacturing processes, the standing wave ratio inevitably increases with increasing transmission speed, leading to a decrease in high-frequency performance. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a slip ring wireless transmission structure for X-ray computed tomography equipment. Through optimized structural design, the system's return loss is improved, its anti-interference capability is enhanced, and its transmission stability and reliability are effectively improved.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A slip ring wireless transmission structure for X-ray tomography equipment includes a transmitting antenna and a receiving antenna. There are N transmitting antennas, each consisting of two transmitting transmission lines connected at the feed end via a transmitting adapter plate. The transmitting transmission lines are matched at the matching end using microstrip end-matching technology. The N transmitting antennas are distributed along the radial outer surface of the slip ring in a circular direction.

[0009] Furthermore, each transmit line comprises two parallel microstrip transmission lines, and each microstrip transmission line has a differential feed port at the feed end.

[0010] Furthermore, the differential feed port is excited by a metal probe, which is connected to a circular pad in the ground plane of the microstrip transmission line. The metal probe, the annular copper avoidance area in the same ground plane, and the surrounding metal layer form a planar coaxial structure.

[0011] Furthermore, the transmitting line has a matching plate on the back of the matching end, and the microstrip transmission line is transitioned to the matching plate on the back through vertical interconnect technology.

[0012] Furthermore, the matching board has a double-layer PCB structure. The upper layer of the matching board is a strip layer, which includes microstrip lines and matching resistors. The lower layer of the matching board is a metal ground layer, and the metal ground layer of the matching board is connected to the metal ground layer of the microstrip transmission line.

[0013] Furthermore, one end of the microstrip line on the matching board is connected to the matching terminal of the microstrip transmission line via a metal probe, and the other end is connected to the matching resistor. The other end of the matching resistor is connected to the surrounding metal ground.

[0014] Furthermore, the characteristic impedance of the microstrip line is consistent with the impedance of the matching resistor.

[0015] Furthermore, both microstrip transmission lines of the transmission line adopt a periodic structure.

[0016] Furthermore, the periodic structure is a periodic "T"-shaped slot distributed on the outside of the microstrip transmission line, wherein the horizontal slots in the "T"-shaped slots are located at the outer edge of the microstrip transmission line, so that the outer edge of the microstrip transmission line presents a periodic "convex" structure.

[0017] Furthermore, the transmitter adapter board is located on the back of the transmitter transmission line. The transmitter adapter board has a four-layer PCB structure. The top layer of the upper PCB includes two pairs of coaxial structures. Each pair of coaxial structures connects to the two differential feed ports of a transmitter transmission line. The bottom layer of the lower PCB includes two pairs of pads. The coaxial structures and pads are connected by metal probes to transfer the feed end of the transmitter transmission line to pads and connectors for connection.

[0018] Furthermore, each coaxial-like structure on the top layer of the upper PCB of the transmitter adapter board consists of a circular pad, a metal probe passing through the circular pad and concentric with the circular pad, an annular copper avoidance area concentric with the pad, a metallized via outside the copper avoidance area, and a copper layer outside the copper avoidance area. The bottom layer of the upper PCB of the transmitter adapter board includes a metal probe penetrating from the top layer to the bottom layer, an annular copper avoidance area centered on the metal probe, and a metallized via on the copper layer outside the annular copper avoidance area. The metal probe on the upper PCB of the transmitter adapter board penetrates to the bottom layer of the lower PCB. The top layer of the lower PCB of the transmitter adapter board includes a metal probe, an annular copper avoidance area centered on the metal probe, and a copper layer outside the copper avoidance area. The metal probe passes through the core of the lower PCB and connects with the pad on the bottom layer of the lower PCB.

[0019] Furthermore, each pair of pads on the bottom layer of the lower PCB is surrounded by metallized vias.

[0020] Furthermore, the bottom layer of the upper PCB and the top layer of the lower PCB of the transmitter adapter board are bonded together using a prepreg.

[0021] Furthermore, the receiving antenna includes a coupling microstrip line and a second pad. The coupling microstrip line comprises two differential microstrip lines for coupling signals from the transmitting line, and the second pad is used to assemble corresponding connectors.

[0022] Furthermore, the receiving antenna has a four-layer PCB structure. The coupling microstrip line is located on the top layer of the upper PCB. The coupling microstrip line is connected to the bottom layer of the upper PCB through a metal probe. The bottom layer of the upper PCB is a metal ground layer, and the top layer of the lower PCB is a metal ground layer. The metal probe of the upper PCB penetrates the lower PCB and connects to the pad on the bottom layer.

[0023] Furthermore, both the bottom layer of the upper PCB and the top layer of the lower PCB of the receiving antenna have annular copper avoidance areas centered on the metal probe.

[0024] Furthermore, the bottom layer of the upper PCB and the top layer of the lower PCB of the receiving antenna are bonded together using a prepreg.

[0025] Furthermore, metallized vias are provided around the coupling microstrip line 9 on the upper PCB board.

[0026] Beneficial effects:

[0027] 1. The slip ring wireless transmission structure of the present invention optimizes the structure of the feed end, matching end and receiving antenna of the transmitting antenna, and uses a periodic microstrip line in the transmitting transmission line. Compared with the wireless transmission structure of existing equipment, it improves the near-field coupling efficiency, effectively improves the system return loss and reduces the signal-to-noise ratio, thereby effectively improving the transmission stability and reliability, and better meeting the application requirements with higher bit error rate requirements.

[0028] 2. In the matching end of the transmitting antenna, the present invention uses vertical connection technology to transition the signal onto the microstrip structure. Compared with the traditional coplanar waveguide method, this matching method is less sensitive to the gap size on the matching board and mainly depends on the linewidth of the microstrip line. The processing difficulty is significantly reduced, the standing wave ratio is effectively optimized, and the return loss of the antenna system is improved.

[0029] 3. The transmitting adapter board and transmitting transmission line of the present invention are connected in a head-to-head manner, and a quasi-coaxial structure is adopted in the vertical connection, which effectively improves the matching of signal feed, reduces signal feed reflection, effectively suppresses the distortion of signal transmission to the transmitting antenna, effectively improves the stability of signal transmission, and can also better match the rectangular connector.

[0030] 3. The receiving antenna of the present invention adopts a four-layer PCB structure. Its coupled signal is transmitted to the pad structure through a probe method. At the same time, the quasi-coaxial double conductor structure is used to effectively suppress the distortion of the coupled signal, thereby improving the signal transmission stability and better matching its connector. Attached Figure Description

[0031] Figure 1 A schematic diagram of the slip ring wireless transmission structure in an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the transmission line (perspective view);

[0033] Figure 3 A schematic diagram of the front structure of the transmission line;

[0034] Figure 4 Schematic diagram of the back structure of the transmission line;

[0035] Figure 5 A schematic diagram of the feed terminal of the transmitting line;

[0036] Figure 6 A schematic diagram of the matching end of the transmitting line;

[0037] Figure 7 Schematic diagram of the transmitter adapter board (perspective view);

[0038] Figure 8 A schematic diagram of the front structure of the transmitter adapter board;

[0039] Figure 9 Schematic diagram of the back structure of the transmitter adapter board;

[0040] Figure 10 A schematic diagram of the receiving antenna (perspective view);

[0041] Figure 11 A schematic diagram of the front structure of the receiving antenna;

[0042] Figure 12 A schematic diagram of the back structure of the receiving antenna.

[0043] Figure label:

[0044] 1 Transmit transmission line, 11 Microstrip transmission line, 12 "T" shaped slot, 13 Differential feed port, 14 Matching board, 15 Microstrip line, 16 Matching resistor; 2 Transmit adapter board, 21 Type-coaxial structure, 22 Pad 1; 3 Receive antenna, 31 Coupled microstrip line, 32 Pad 2, 4 Circular pad, 5 Metal ground layer, 6 Metal probe, 7 Metallized via, 8 Annular copper avoidance area. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0046] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0047] The orientations or positional relationships indicated by terms such as "up," "down," "left," "right," "middle," "longitudinal," "lateral," "horizontal," "inner," "outer," "radial," and "circumferential" in this specification are based on the orientations or positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description. They 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 limiting the present invention.

[0048] The slip ring wireless transmission structure of this invention is applied in a computer X-ray computed tomography (CT) scanner to realize data transmission between rotating and stationary parts, such as... Figure 1As shown, the passive components of the slip ring wireless transmission mainly consist of three parts: a transmitting transmission line 1, a transmitting adapter plate 2, and a receiving antenna 3. The transmitting transmission line 1 is used to transmit wireless radio frequency signals, enabling the wireless radio frequency signals to be transmitted on the radial side of the slip ring. The transmitting adapter plate 2 is used to combine the transmitting transmission line 1 to meet the transmission requirements of different slip rings. The transmitting transmission line 1 and the transmitting adapter plate 2 together form the transmitting antenna. The receiving antenna 3 is used to couple the required radio frequency signals from the transmitting transmission line 1 for backend recovery of the required information.

[0049] Specifically, the transmission line 1 is fixed to the radial outer side of the slip ring. In this embodiment of the invention, the number of transmission lines 1 on the outer side of each slip ring is 2N (N is an integer greater than zero). The 2N transmission lines 1 are composed of N pairs of transmission adapter plates 2, covering the entire radial outer side area of ​​the slip ring. The specific number of transmission lines is determined by the transmission line loss and the diameter of the slip ring. The number of transmission adapter plates 2 connecting the transmission lines 1 is N. Each pair of transmission lines 1 is connected by one transmission adapter plate 2 to form a transmission antenna. The entire radial side of the slip ring is covered by N pairs of transmission lines 1, i.e., N transmission antennas.

[0050] The structure of transmission line 1 is as follows Figure 2-3 As shown, each transmit transmission line 1 comprises two parallel microstrip transmission lines 11 for transmitting differential signals. Each microstrip transmission line 11 includes a feed end and a matching end. The microstrip transmission line 11 has a differential feed port 13 at its feed end, as shown... Figure 2 and 5 As shown, the differential feed port 13 is excited by a metal probe (not shown in the figure due to obstruction). The metal probe is connected to the circular pad 4 in the ground layer of the microstrip transmission line 11, and forms a planar coaxial structure with the annular copper avoidance area 8 and the surrounding metal layer in the same ground layer. Each feed end of the transmit transmission line 1 contains a total of 2 planar coaxial structures, namely a pair of differential feed ports 13.

[0051] In this embodiment of the invention, in order to increase the coupling between the transmitting transmission line 1 and the receiving antenna 3, and to enable the transmitting transmission line 1 to have a wider field distribution in the width direction, the two microstrip transmission lines 11 of the transmitting transmission line 1 adopt a periodic structure, such as... Figure 2-3 As shown, the periodic structure of the microstrip transmission line 11 is composed of periodic "T"-shaped slots 12 distributed at the outer edge of the microstrip transmission line 11. The horizontal slots on the "T"-shaped slots 12 are located at the outer edge of the microstrip transmission line 11 and are parallel to the length direction of the microstrip transmission line 11, so that the outer edge of the microstrip transmission line 11 presents a periodic "convex" structure.

[0052] Compared to aperiodic microstrip lines, periodic microstrip lines have a wider field distribution range and stronger coupling between transmitter and receiver. Furthermore, periodic microstrip lines come in various forms and have more adjustable parameters, which is beneficial for improving performance. By appropriately adjusting the size of the specific pattern of the "T"-shaped slot 12 and the periodic spacing, the differential transmission coefficient between the transmitting transmission line 1 and the receiving antenna 3 can be increased by 2~3dB compared to the aperiodic microstrip line structure, which facilitates signal transmission.

[0053] The electromagnetic waves on the transmitting line 11 propagate in the form of traveling waves. To achieve traveling wave transmission, the ends of the two microstrip transmission lines 11 of the transmitting line 1 need to be matched. For the end matching structure of differential transmission lines, coplanar waveguide matching technology is traditionally used. However, considering the actual PCB manufacturing level, the gaps on both sides of the coplanar waveguide strip are difficult to process. To improve the matching performance, this invention uses microstrip end matching technology. At the end of the microstrip transmission line 11, a metal probe 6 is used to transition the microstrip transmission line 11 to the matching board 14 on the back side through vertical interconnect technology.

[0054] The matching board 14 is a PCB board fixed to the back of the matching end of the microstrip transmission line 11, such as... Figure 4 and 6 As shown, the upper layer of the matching plate 14 is a stripline layer, which includes a microstrip line 15 and a matching resistor 16. The lower layer of the matching plate 14 is a metal ground layer 5. The metal ground layer 5 of the matching plate 14 is bonded to the metal ground layer 5 of the transmission microstrip line 15 and welded together. In the matching plate 14, one end of the microstrip line 15 is connected to the matching terminal of the microstrip transmission line 11 through a metal probe 6, and the other end is connected to the matching resistor 16. One end of the matching resistor 16 is connected to the microstrip line 15, and the other end is connected to the surrounding metal ground. The characteristic impedance of the microstrip line 15 is the same as the impedance of the matching resistor 16.

[0055] The microstrip end matching technology used in this invention is less sensitive to the gap size and has a lower manufacturing difficulty compared to traditional coplanar waveguide technology. It mainly achieves matching by controlling the linewidth of the microstrip line 15, which can effectively optimize its standing wave ratio and thus improve the return loss of the antenna system.

[0056] The structure of the transmitter adapter board 2 is as follows Figure 7-9 As shown, the transmitter adapter board 2 is used to connect the two transmitter transmission lines 1 at the feed end in a port-to-port manner, and to transfer the two pairs of differential feed ports 13 to the rear end for connection with the corresponding connectors. The port-to-port manner refers to the arrangement of the two transmitter transmission lines 1 with the feed ends adjacent to each other.

[0057] In this embodiment of the invention, the transmitting adapter board 2 is a 4-layer (two-core) PCB structure. The top layer of the upper PCB is consistent with the feed terminal of the transmitting transmission line 1, consisting of two pairs of coaxial-like structures 21. Each coaxial-like structure comprises a circular pad 4, a metal probe 6 passing through the circular pad 4 and concentric with the circular pad 4, an annular copper avoidance area 8 concentric with the pad, metallized vias 7 distributed circumferentially outside the copper avoidance area, and a copper layer outside the copper avoidance area. The bottom layer of the upper PCB includes a metal probe 6 penetrating from the top layer to the bottom layer, an annular copper avoidance area 8 centered on the metal probe 6, and metallized vias 7 distributed circumferentially on the copper layer outside the annular copper avoidance area 8. The metallized vias 7 penetrating the upper core and connecting the top and bottom layers of the upper PCB serve as the outer conductor of the coaxial-like structure 21 and can also shield other interference signals.

[0058] The metal probe 6 of the upper PCB of the transmitter adapter board 2 penetrates to the bottom layer of the lower PCB, meaning the metal probe 6 of the transmitter adapter board 2 directly inserts into the upper and lower dielectric layers, vertically connecting the trace layers of the upper and lower PCBs. The top layer of the lower PCB of the transmitter adapter board 2 has the same structure as the bottom layer of the upper PCB, including the metal probe 6, an annular copper avoidance area 8 centered on the metal probe 6, and a copper layer outside the annular copper avoidance area 8. The metal probe 6 passes through the core of the lower PCB and connects to pad 22 on the bottom layer of the lower PCB. The metal probe 6 can excite a quasi-TEM mode on pad 22 and perform impedance matching with pad 22. In this embodiment, pad 22 is a rectangular microstrip pad. Two pairs of pads 22 are provided on the bottom layer of the lower PCB, and each pair of pads 22 is surrounded by metallized vias 7 to facilitate the isolation of interference signals.

[0059] The bottom layer of the upper PCB of the transmitter adapter board 2 is bonded to the top layer of the lower PCB through a prepreg. In use, the size of the rectangular microstrip pad 22 can be adjusted by adjusting the thickness and dielectric constant of the lower PCB to meet the needs of different connectors.

[0060] Each transmit adapter board 2 connects two transmit transmission lines 1. Each transmit adapter board 2 has two pairs of coaxial structures 21. Each pair of coaxial structures 21 connects two differential feed ports of one transmit transmission line 1. The two pairs of coaxial structures 21 connect the two transmit transmission lines 1 in a manner where the feed ends are adjacent to each other (i.e., port to port). The transmit adapter board 2 and the transmit transmission line 1 are connected in a "T" shaped structure in cross-section. At the same time, the use of coaxial structures 21 in the vertical connection can effectively improve the matching of signal feed, reduce signal feed reflection, effectively suppress the distortion of signal transmission to the transmitting antenna, effectively improve the stability of signal transmission, and also better match the rectangular connector.

[0061] like Figure 10-12As shown, the receiving antenna 3 couples signals from the transmitting transmission line 1 for backend processing. The receiving antenna 3 mainly includes a coupling microstrip line 31 and a second pad 32. The coupling microstrip line 31 contains two differential microstrip lines that couple signals from the transmitting transmission line 1, and the second pad 32 is used to mount corresponding connectors.

[0062] In this embodiment of the invention, the receiving antenna 3 is a four-layer PCB (two-core) structure. The coupling microstrip line 31 is located on the top layer of the upper PCB, and the second pad 32 is located on the bottom layer of the lower PCB. The bottom layer of the upper PCB is a metal ground plane 5. Two differential microstrip lines are connected to the bottom layer of the upper PCB via two metal probes 6. A ring-shaped copper avoidance area 8 centered on the two probes exists on the bottom layer of the upper PCB. Simultaneously, to reduce the influence of other devices on the coupling microstrip line 31, metallized vias 7 are arranged around the coupling microstrip line 31 on the upper PCB. The metal probes 6 of the upper PCB penetrate to the lower PCB. The top layer pattern of the lower PCB is consistent with the bottom layer pattern of the upper PCB, which is a metal ground plane 5. A copper avoidance area is arranged around the metal probes 6. The metal probes 6 pass through the lower PCB to the bottom layer of the lower PCB and connect to the second pad 32.

[0063] In receiving antenna 3, the bottom layer of the upper PCB and the top layer of the lower PCB are bonded together using a prepreg. Receiving antenna 3 adopts a four-layer PCB structure. The coupling microstrip line 31 of the upper PCB is connected to the pad 10 of the bottom layer of the lower PCB through two metal probes 6. The coupled signal is transmitted to the pad structure through the probes. At the same time, the coaxial dual-conductor structure is used to effectively suppress the distortion of the coupled signal, thereby improving the signal transmission stability. The size of the pad 10 can be adjusted by adjusting the thickness and dielectric constant of the lower PCB to meet different connection requirements.

[0064] In use, the slip ring wireless transmission structure uses a transmitting adapter plate 2 to assemble the transmitting transmission line 1 into a transmitting antenna, which is then covered on the outer periphery of the slip ring. The receiving antenna 3 is fixed on the equipment bracket. The connector on the back of the transmitting adapter plate 2 is connected to the detector on the equipment. When the equipment is running, the wireless radio frequency signal is transmitted radially along the slip ring via the transmitting transmission line 1. As the slip ring rotates, the transmitting antenna passes by the receiving antenna 3, causing the signal propagating on the transmitting transmission line 1 to be coupled into the receiving antenna 3. The radio frequency signal coupled to the receiving antenna 3 is transmitted to the computer equipment for back-end processing through the connector on the back of the receiving antenna 3 to generate CT images.

[0065] Compared with existing slip-ring wireless transmission equipment, this system enhances the field strength in near-field coupled transmission. Through optimized design of the matching end of the transmitting antenna, the receiving antenna, and the transmitting adapter board, the return loss of the system is effectively improved, resulting in a better signal-to-noise ratio. This effectively improves transmission stability and reliability, better meeting the application requirements with higher bit error rate requirements.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. Slip ring wireless transmission structure for application to an X-ray tomography apparatus, comprising a transmitting antenna and a receiving antenna (3), characterized in that, The transmitting antenna has N, each transmitting antenna is connected by two transmitting transmission lines (1) at the feeding end through the transmitting adapter plate (2), the transmitting transmission line (1) is matched at the matching end using microstrip end matching technology, N transmitting antennas can be distributed on the radial outer side of the slip ring in the circumferential direction, each transmitting transmission line (1) contains two parallel distributed microstrip transmission lines (11), the two microstrip transmission lines (11) of the transmitting transmission line (1) adopt a periodic structure, the periodic structure is a periodic "T" shaped slot (12) distributed outside the microstrip transmission line (11), wherein the horizontal slot in the "T" shaped slot (12) is located at the outer edge of the microstrip transmission line (11), so that the outer edge of the microstrip transmission line (11) presents a periodic "convex" structure.

2. The slip ring wireless transmission structure applied to an X-ray tomography device according to claim 1, characterized in that, Each microstrip transmission line (11) is provided with a differential feeding port (13) at the feeding end.

3. The slip ring wireless transmission structure applied to the X-ray tomography device according to claim 2, characterized in that, The differential feeding port (13) is excited by a metal probe (6), the metal probe (6) is connected to the circular pad (4) at the ground layer of the microstrip transmission line (11), and the metal probe (6) and the surrounding metal layer form a planar coaxial structure with the same ground layer.

4. The slip ring wireless transmission structure applied to the X-ray tomography device according to claim 2, characterized in that, The transmitting transmission line (1) is provided with a matching plate (14) on the back of the matching end, and the microstrip transmission line (11) is transitioned to the matching plate (14) on the back through vertical interconnection technology.

5. The slip ring wireless transmission structure applied to the X-ray tomography device according to claim 4, characterized in that, The matching plate (14) is a double-layer PCB structure, the upper layer of the matching plate (14) is a strip line layer, including a microstrip line (15) and a matching resistor (16), and the lower layer of the matching plate (14) is a metal ground layer (5), and the metal ground layer (5) of the matching plate (14) is connected together with the metal ground layer (5) of the microstrip transmission line (11).

6. The slip ring wireless transmission structure applied to the X-ray tomography device according to claim 5, characterized in that, One end of the microstrip line (15) on the matching plate (14) is connected to the matching end of the microstrip transmission line (11) through the metal probe (6), and the other end is connected to the matching resistor (16), and the other end of the matching resistor (16) is connected to the surrounding metal ground.

7. The slip ring wireless transmission structure applied to the X-ray tomography device according to claim 5, characterized in that, The characteristic impedance of the microstrip line (15) is consistent with the impedance of the matching resistor (16).

8. The slip ring wireless transmission structure applied to the X-ray tomography device according to claim 3, characterized in that, The transmitting adapter plate (2) is a four-layer PCB structure, the top layer of the upper layer PCB includes two pairs of coaxial structures (21), each pair of coaxial structures (21) connects two differential feeding ports (13) of one transmitting transmission line (1), and the bottom layer of the lower layer PCB includes two pairs of pad one (22), the coaxial structures (21) and the pad one (22) are connected through the metal probe (6), the feeding end of the transmitting transmission line (1) is connected to the pad one (22) through the metal probe (6) to realize the connection with the connector.

9. The slip ring wireless transmission structure applied to the X-ray tomography device according to claim 8, characterized in that, Each identical coaxial structure (21) of the top layer of the upper layer PCB of the transmitting adapter board (2) is composed of a circular pad (4), a metal probe (6) passing through the circular pad (4) and concentric with the circular pad (4), a ring-shaped copper-avoiding area (8) concentric with the pad, a metalized via (7) outside the copper-avoiding area, and a copper layer outside the copper-avoiding area. The bottom layer of the upper layer PCB of the transmitting adapter board (2) includes the metal probe (6) passing from the top layer to the bottom layer, the ring-shaped copper-avoiding area (8) centered on the metal probe (6), and the metalized via (7) on the copper layer outside the ring-shaped copper-avoiding area (8). The metal probe (6) on the upper layer PCB of the transmitting adapter board (2) penetrates to the bottom layer of the lower layer PCB. The top layer of the lower layer PCB of the transmitting adapter board (2) includes the metal probe (6), the ring-shaped copper-avoiding area (8) centered on the metal probe (6), and the copper layer outside the copper-avoiding area. The metal probe (6) passes through the board core of the lower layer PCB and is connected to the pad one (22) on the bottom layer of the lower layer PCB.

10. The slip ring wireless transmission structure applied to an X-ray tomography device according to claim 8, characterized in that, The outer periphery of each pair of pad one (22) of the bottom layer of the lower layer PCB of the transmitting adapter board (2) is surrounded by a metalized via (7).

11. The slip ring wireless transmission structure applied to an X-ray tomography device according to claim 8, characterized in that, The bottom layer of the upper layer PCB and the top layer of the lower layer PCB of the transmitting adapter board (2) are bonded by a prepreg.

12. The slip ring wireless transmission structure applied to an X-ray tomography device according to claim 1, characterized in that, The receiving antenna (3) includes a coupling microstrip line (31) and a pad two (32). The coupling microstrip line (31) includes two differential microstrip lines (15) for coupling signals from the transmitting transmission line (1). The pad two (32) is used to assemble a corresponding connector.

13. The slip ring wireless transmission structure applied to an X-ray tomography device according to claim 12, characterized in that, The receiving antenna (3) is a four-layer PCB structure. The coupling microstrip line (31) is located on the top layer of the upper layer PCB. The coupling microstrip line (31) is connected to the bottom layer of the upper layer PCB through a metal probe (6). The bottom layer of the upper layer PCB is a metal ground layer (5). The top layer of the lower layer PCB board is a metal ground layer (5). The metal probe (6) of the upper layer PCB penetrates the lower layer PCB and is connected to the pad two (32) of the bottom layer.

14. The slip ring wireless transmission structure applied to an X-ray tomography device according to claim 13, characterized in that, The bottom layer of the upper layer PCB and the top layer of the lower layer PCB of the receiving antenna (3) both have a ring-shaped copper-avoiding area (8) centered on the metal probe (6).

15. The slip ring wireless transmission structure applied to the X-ray tomography device according to claim 13, characterized in that, The bottom layer of the upper layer PCB and the top layer of the lower layer PCB of the receiving antenna (3) are bonded by a prepreg.

16. The slip ring wireless transmission structure applied to an X-ray tomography device according to claim 13, characterized in that, The receiving antenna (3) is a four-layer PCB structure. The coupling microstrip line (31) is located on the top layer of the upper layer PCB. The coupling microstrip line (31) is connected to the bottom layer of the upper layer PCB through a metal probe (6). The bottom layer of the upper layer PCB is a metal ground layer (5). The top layer of the lower layer PCB board is a metal ground layer (5). The metal probe (6) of the upper layer PCB penetrates the lower layer PCB and is connected to the pad two (32) of the bottom layer.

Images