CN217359676U - Capacitive coupling slip ring - Google Patents

Abstract

The utility model relates to a capacitive coupling formula sliding ring belongs to X ray computed tomography imaging technique (for short "CT technique") technical field, has solved the sliding ring among the prior art and has improved entire system's communication rate through the width that widens the rotary disk, leads to the equipment volume increase to problem with high costs. The capacitive coupling slip ring comprises a disc body, a sending unit and a receiving unit, wherein the sending unit comprises a sending antenna and a sending end data processing unit; the disc body is hollow and annular, a first groove is circumferentially arranged on the inner surface of the disc body, the shape of the first groove is matched with that of the transmitting antenna, and the transmitting antenna is arranged in the first groove. The utility model discloses a multichannel data transmission.

Description

Capacitive coupling slip ring

Technical Field

The utility model relates to an X-ray computed tomography imaging technique (be referred to as "CT technique") technical field especially relates to a capacitive coupling formula sliding ring.

Background

The X-ray computed tomography imaging technology (abbreviated as "CT technology") is highly valued and widely used in the field of security inspection because of its own unique advantages.

Capacitively coupled slip rings are one of the key components of a CT for power and data transfer between the rotor and stator ends of the CT.

At present, the common non-contact conductive slip ring and the data transmission mode between rotating bodies mainly comprise two modes of wireless capacitance coupling transmission and optical transmission.

The capacitive coupling slip ring realizes the transmission of signals through the capacitive coupling between a flexible antenna surrounding the outer edge of the rotating disk and a receiving antenna at the fixed end. Compared with an optical transmission electric slip ring, the capacitive coupling slip ring has the advantages of small volume, light weight, small occupied space and low cost; there are, however, electromagnetic radiation generated and susceptible to electromagnetic interference; the change of the distance between the moving coil and the static coil can influence the data acquisition, so that the data transmission rate is difficult to meet the requirement.

The capacitively coupled slip ring transmit antenna and the receive antenna are both printed circuit boards. The printed circuit board material characteristics and the plug-in connection mode have the problem of signal integrity effect along with the improvement of the transmission signal frequency; in combination with the principle of wireless capacitive coupling transmission, the maximum rate of signal transmission is limited, and the signal transmission rate cannot be increased infinitely. The highest signal transmission rate of a single-channel transmitting antenna in the market is 10 Gbps. As the data amount of transmission information increases, higher requirements are also placed on the transmission rate and the error rate.

The prior art generally increases the communication rate of the entire system by increasing the number of communication channels while ensuring a transmission rate of 10Gbps per channel by increasing the width of the over-widening rotating disk. But increasing the width of the rotating disk increases the volume of the device and increases the cost.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing analysis, the present invention is directed to a capacitive coupling slip ring to solve the problem that the existing slip ring increases the communication speed of the whole system by increasing the width of the over-widened rotating disk, resulting in an increased device size and high cost.

The purpose of the utility model is mainly realized through the following technical scheme:

a capacitive coupling slip ring comprises a disc body, a sending unit and a receiving unit, wherein the sending unit comprises a sending antenna and a sending end data processing unit; the disc body is hollow and annular, a first groove is circumferentially arranged on the inner surface of the disc body, the shape of the first groove is matched with that of the transmitting antenna, and the transmitting antenna is arranged in the first groove; the outer surface of the tray body is provided with a second groove which is circumferentially arranged, the shape of the second groove is matched with that of the transmitting antenna, and the transmitting antenna is arranged in the second groove.

Based on a further improvement of the above capacitively coupled slip ring, the position of the first groove and the position of the second groove correspond.

Based on the further improvement of the capacitive coupling slip ring, the transmitting end data processing unit comprises a transmitting circuit board and a data line, and the transmitting antenna and the data line are both connected with the transmitting circuit board.

Based on the further improvement of the capacitive coupling slip ring, the transmitting circuit board is fixed on the disc body.

Based on the further improvement of the capacitive coupling slip ring, the number of the first grooves and the second grooves is at least 1.

Based on the further improvement of the capacitive coupling slip ring, the receiving unit comprises a receiving end data processing unit and a receiving antenna.

Based on a further improvement of the above capacitively coupled slip ring, the receiving unit comprises a first receiving unit and a second receiving unit, the first receiving unit is arranged near the inner surface of the rotating disk.

Based on the further improvement of the capacitive coupling slip ring, the distance between the first receiving unit and the transmitting antenna in the first groove is 1.5-5 mm.

Based on the further improvement of the capacitive coupling slip ring, the transmitting antenna is pasted in the first groove.

Based on the further improvement of the capacitive coupling slip ring, the number of the transmitting antennas is multiple, and the multiple transmitting antennas surround a circle.

Compared with the prior art, the utility model discloses can realize one of following beneficial effect at least:

(1) in order to increase the communication rate of the entire system, the prior art has generally increased the number of communication channels by widening the width of the rotating disk while ensuring a transmission rate of 10Gbps per channel. But increasing the width of the rotating disk increases the volume of the device and increases the cost. The utility model discloses a set up transmitting antenna simultaneously at rotary disk internal surface and surface, can increase the communication channel number under the condition that does not increase the rotary disk width, improve entire system's communication rate.

(2) In order to prevent the signal interference between the different transmitting antenna of homonymy, interval between the different transmitting antenna of homonymy among the prior art is not less than the triple (3W promptly) of transmitting antenna width W, the utility model discloses an embedded receiving antenna's scheme, the degree of depth that is used for placing transmitting antenna's recess on the rotary disk promptly is greater than transmitting antenna's thickness, and after transmitting antenna placed the recess in, there was the difference in height upper surface and the surface of rotary disk transmitting antenna. Above-mentioned setting can effectively reduce the radiation field of sending signal, consequently, even reduce under the condition of the interval between the different groups of sending antenna, also can reduce the interference between the different receiving and dispatching module groups, under the condition of guaranteeing that the signal normally communicates, effectively improves the utilization ratio of electrical slip ring disk body.

(3) In the prior art, a PCB is usually used as a capacitive coupling antenna, and the PCB is brittle, so that the capacitive coupling antenna made of the PCB is easily broken in the bending process, and the length of the capacitive coupling antenna made of the produced PCB is limited and generally does not exceed 2.5 m. Therefore, when the two capacitively coupled antennas made of the PCB are wound around the rotating disk, there is a distance between the signal output terminal and the signal input terminal of the two antennas due to the limited length, thereby reducing the signal transmission efficiency. Because the antenna is easy to break in the bending process, the two antennas are likely to lose the information transmission function in the use process. The utility model discloses utilize polyethylene or tetrafluoroethylene to make capacitive coupling formula antenna for the substrate for capacitive coupling formula antenna has enough flexibility and the antenna length who generates can reach more than 2m, and can guarantee that the condition of rupture can not appear at the in-process of buckling of antenna, thereby has improved the transmission efficiency of signal.

(4) The utility model discloses a CT detection device includes the rotary disk, and capacitive coupling formula antenna (transmitting antenna) need twine on the rotary disk usually to the accompanying rotary disk carries out 360 degrees rotations. Therefore, the utility model discloses transmitting antenna is connected with the form that sends communication module and pass through the connector to the capacitively coupled antenna goes on 360 degrees rotations along with the rotary disk.

The utility model discloses in, can also make up each other between the above-mentioned each technical scheme to realize more preferred combination scheme. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout the drawings.

Fig. 1 is a schematic structural view of a capacitive coupling slip ring according to an embodiment of the present invention;

FIG. 2 is a partial cross-sectional view of a rotating disk according to an embodiment of the present invention;

FIG. 3 is a graph of spacing between adjacent transmit antennas versus antenna width for a prior art system;

fig. 4 is a partial sectional view of a rotating disk with a built-in transmitting antenna according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a CT detection apparatus according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a two-layer circuit board according to an embodiment of the present invention;

fig. 7 is a CT diagram.

Reference numerals:

1-rotating the disc; 2-a transmit antenna; 3-a first groove; 4-a second groove; 5-a receiving unit; 6-a plug-in; 7-a first metallic copper foil; 8-a substrate; 9-a second metallic copper foil; 10-a radiation source; 11-a CT gantry; a 30-CT detector; 40-detected object; 50-a conveyor belt; 60-conveyor belt motor; 70-a motion control computer; 80-slip ring motor; 90-data processing computer.

Detailed Description

The following detailed description of the preferred embodiments of the invention, which is to be read in connection with the accompanying drawings, forms a part of the invention, and together with the embodiments of the invention, serve to explain the principles of the invention and not to limit the scope of the invention.

Example one

The utility model discloses a concrete embodiment discloses a capacitive coupling formula sliding ring, including rotary disk 1, transmitting element and receiving element.

As shown in fig. 1, the sending unit includes a sending antenna 2 and a sending-end data processing unit, the sending-end data processing unit includes a sending circuit board and a data line, and both the sending antenna 2 and the data line are connected to the sending circuit board. The transmitting antenna 2 is connected to the transmitting circuit board by means of a connector, for example. The transmitting circuit board is fixed on the rotating disc.

The utility model discloses a shape of sending antenna be the platykurtic, or the strip form.

The rotating disc is in a hollow large-aperture ring shape, a first groove 3 is circumferentially arranged on the outer surface of the rotating disc, the shape of the first groove 3 is matched with that of the transmitting antenna 2, and the transmitting antenna 2 is arranged in the first groove 3.

It should be noted that, depending on the diameter of the rotating disk, the number of the transmitting antennas located in the first groove 3 may be 1, or a plurality of transmitting antennas may form a complete circle. Specifically, the circuit board has two vias, and the adjacent antennas are connected to one via of the circuit board, respectively. The receiving unit comprises a receiving circuit board and a data line, and the data line is connected with the receiving circuit board.

The receiving unit 5 comprises two parts, namely a receiving end data processing unit and a receiving antenna, which can be integrated on a printed circuit or connected in a plug-in manner.

The receiving unit comprises a first receiving unit and a second receiving unit, wherein the first receiving unit is arranged near the outer surface of the rotating disc and is 1.5-5mm away from the transmitting antenna in the first groove.

In a possible embodiment, the inner surface of the rotating disc 1 is also provided with a circumferentially arranged groove (second groove 4), as shown in fig. 2. The shape of the second recess 4 matches the shape of the transmitting antenna, which is placed in the second recess.

It should be noted that the transmitting antenna 2 in the present embodiment is fixed in the groove, and for example, the transmitting antenna may be fixed in the groove by means of adhesion.

The second receiving unit is arranged near the inner surface of the rotating disk and is 1.5-5mm away from the transmitting antenna in the second groove.

It should be noted that the number of the first grooves 3 and the second grooves 4 is at least one. For example, 1 first groove, 1 second groove; or 1 first groove and 2 second grooves; 2 first grooves and 1 second groove; alternatively, 2 first grooves, 2 second grooves, as shown in fig. 2. The position of the second groove may or may not correspond to the position of the first groove.

The transmission unit and the receiving unit are realized by a capacitive coupling principle, namely, electric field coupling between the transmitting antenna and the receiving antenna. If the distance between the different groups of transceiving antennas is too close, crosstalk between different transceiving modules occurs, which causes abnormal communication. Therefore, in order to prevent signal interference between the different transmitting antennas on the same side, the spacing D between the different transmitting antennas on the same side in the related art is not less than three times the width W of the transmitting antenna (i.e., 3W), and the dielectric thickness H between the different transmitting antennas on different sides is not less than three times the width of the transmitting antenna, as shown in fig. 3 (the transmitting antennas are illustrated as protruding the outer surface of the rotating disk for convenience of expression).

However, due to space constraints, it is not possible to increase the distance between different transceiver modules indefinitely. Therefore, in a possible embodiment of the present invention, a solution of embedded receiving antenna is adopted, i.e. the depth of the groove is not the same as the thickness of the transmitting antenna, but the depth of the groove is greater than the thickness of the transmitting antenna, as shown in fig. 4. Thus, after the transmitting antenna is placed in the groove, the upper surface of the transmitting antenna has a height difference from the outer surface of the rotating disk, i.e., the upper surface of the transmitting antenna is not flush with the outer surface of the rotating disk, but is lower than the outer surface of the rotating disk.

Specifically, the thickness of the antenna is 2mm, and the depth of the groove is 3 mm. So that the surface of the transmitting antenna is at a distance of 1mm from the side of the rotating disc. Above-mentioned setting can effectively reduce the radiation field of sending signal, consequently, even reduce under the condition of the interval between the different groups of transmitting antenna, also can reduce the interference between the different receiving and dispatching module groups, under the circumstances of guaranteeing signal normal communication, effectively improves the utilization ratio of electrical slip ring disk body.

The utility model discloses an experimental study discovers, adopts the above-mentioned embedded structure setting, and interval between the sending antenna of homonymy need not reach 3 times (3W promptly) of sending antenna width, only need just can guarantee normal communication for sending antenna width 1-2 times.

Example two

The utility model discloses a CT detection device is disclosed to another embodiment, and capacitive coupling formula sliding ring is one of CT's key parts for power and data transmission between CT rotor end and the stator end.

With the improvement of CT technology, the amount of data collected by the detector is increasing day by day, and the required data transmission bandwidth can be estimated by formula 6, so as to obtain the following corresponding relationship between the number of CT layers and the data bandwidth. Equation 6:

wherein S is data transmission bandwidth; p is the number of channels of the multi-layer spiral CT DAS; n is the number of single-layer spiral CT detectors; m is the single sampling data bit number of each detector; v is the slip ring rotation speed; f is the sampling frequency.

The corresponding relation between the CT layer number and the data bandwidth is as follows:

according to the corresponding relation between the CT layer number and the data bandwidth, the data transmission bandwidth of the 16-layer spiral CT needs to reach 1.25Gbps, the data transmission bandwidth of the 64-layer spiral CT needs to reach 5Gbps, the data transmission bandwidth of the 256-layer spiral CT needs to reach 20Gbps, and the data bandwidth requirement of the 640-layer spiral CT reaches 50 Gbps. The single channel capacitive coupling transmission can't meet the demands, consequently the utility model provides a scheme of multichannel transmission.

The CT detecting apparatus of the present embodiment includes a radiation source 10, a rotating disk 1 and a CT detector 30, a conveyor 50, a data processing unit 90, a conveyor motor 60, a slip ring motor 80, and a motion control computer 70, as shown in fig. 5. The radiation source 10 is fixed on the rotating disk 1, the conveyor belt 50 passes through the hollow large aperture of the rotating disk 1, the detected object 40 is arranged on the conveyor belt 50, and the CT detector 30 is also fixed on the rotating disk 1. The conveyor belt 50 is connected with a conveyor belt motor 60, the rotating disc 1 is connected with a slip ring motor 80, both the conveyor belt motor 60 and the slip ring motor 80 are connected with a motion control computer 70, and the CT detector 30 is connected with a data processing unit 90.

The specific operation mode of the CT detection apparatus of this embodiment is that when the object 40 is subjected to security inspection, the rotating disk 1 rotates to drive the radiation source 10 and the CT detector 30 to rotate 360 degrees, so as to obtain images of the object 40 from multiple angles. Wherein, the transmitting antennas wound along the circumference of the outer and inner surfaces of the rotating disk 1 are used for transmitting the images obtained by the CT detector 30 to the data processing unit 90.

EXAMPLE III

The existing transmitting antenna is usually a capacitive coupling antenna, which is usually made of Printed Circuit Boards (PCBs). The PCB takes an insulating plate as a base material, is cut into a certain size, is provided with at least one conductive pattern and is provided with holes (such as element holes, fastening holes, metalized holes and the like) for replacing a chassis of the electronic components of the prior device and realizing the mutual connection of the electronic components. They are called "printed" circuit boards because they are made by electronic printing. The present PCB board is mainly composed of circuit and drawing surface, dielectric layer, holes, solder resist ink, silk screen and surface treatment.

The capacitive coupling antenna made of the PCB has the advantages that: because the PCB pattern has repeatability (reproducibility) and consistency, errors of wiring and assembly are greatly reduced, and the time for maintaining, debugging and checking the antenna is saved. The antenna has the characteristics of capability of being replaced, convenience, precision, miniaturization and the like due to the characteristics of standardization, small volume, light weight and the like in design.

The capacitive coupling antenna made of the PCB has the defects that the circuit board with ultra-long and flexible requirements has the limitations of high cost and long period, and even the capacitive coupling antenna cannot be produced due to the process limitation

The present embodiment provides a capacitively coupled antenna for CT detection, as shown in fig. 6, including: an insert 6, a first metal copper foil 7, a substrate 8 and a second metal copper foil 9. The first metal copper foil 7 is composed of an upper copper foil wire and a lower copper foil wire, and the upper copper foil wire and the lower copper foil wire are differential wires. The interposer 6, upper copper foil traces and lower copper foil traces are disposed on one side of the substrate 8. On the other surface of the substrate 8, a second metal copper foil 9 is disposed, the second metal copper foil 9 also includes a plug-in 6, an upper copper foil trace and a lower copper foil trace, and the upper copper foil trace and the lower copper foil trace are differential lines. Wherein, the material of substrate is polyethylene or polytetrafluoroethylene to guarantee that the length of circuit board can be greater than 2 m. In this way, two capacitive coupling antennas installed on the rotating disk can realize mutual contact between the signal output end and the signal input end so as to reduce the attenuation of signals in the transmission process. Simultaneously, the pliability of polyethylene and polytetrafluoroethylene can be guaranteed the utility model discloses a capacitive coupling formula antenna is difficult for the fracture when buckling and has further improved the transmission efficiency of signal.

In the embodiment of the utility model provides an in, communication module is connected to one side of plug-in components 6, and the downside copper foil line is walked on the opposite side connection.

In an embodiment of the present invention, the process parameters of the circuit include: the thickness of the substrate, the thickness of the upper copper foil wire, the copper foil width of the upper copper foil wire, the thickness of the lower copper foil wire and the copper foil width of the lower copper foil wire.

Specifically, the thickness of the substrate is; 0.7mm-1.0 mm; the dielectric constant of the substrate is 2.2-2.8:

the thickness of the upper copper foil routing is as follows: 0.1mm-0.2 mm; the width of the copper foil of the upper copper foil routing is as follows: 4mm-7 mm.

The thickness of the lower copper foil routing is as follows: 0.1mm-0.2 mm; the copper foil width of the lower copper foil routing is as follows: 3cm-5 cm.

The above parameters are determined based on the selection of the substrate. Qualitatively, Polyethylene (PE) is a thermoplastic resin obtained by polymerizing ethylene, and is typically a soft and tough polymer. The volume resistivity of PE is high, and the dielectric constant and the dielectric loss tangent are small, and are hardly influenced by frequency.

The polytetrafluoroethylene has excellent chemical stability, corrosion resistance, sealing property, high lubrication non-sticking property, electric insulation property and good ageing resistance. The polytetrafluoroethylene is high-temperature resistant, the working temperature can reach 250 ℃, meanwhile, the polytetrafluoroethylene is low-temperature resistant, has good mechanical toughness at low temperature, and can keep 5% of elongation even if the temperature is reduced to-196 ℃.

The utility model discloses a polyethylene and/or polytetrafluoroethylene can increase the flexibility of circuit board as the matrix, greatly increases the length of circuit board to it is difficult to fracture under the winding state to make it.

Based on the impedance matching nature of medium thickness, conductor width (line width is walked to upper and lower copper foil) and metal thickness (the copper foil is walked line thickness about promptly), the utility model discloses medium thickness, conductor width (the copper foil is walked line width about) and metal thickness (the copper foil is walked line thickness about promptly) when adopting polyethylene and/or polytetrafluoroethylene as the matrix have carried out flexible circuit's impedance matching design. The characteristic impedance of the single conductor of the strip line is calculated as formula 1, and the differential impedance is calculated as formula 2.

Equation 1:

equation 2:

Z ₀ is characteristic impedance (in ohms), H represents the thickness of the medium between the signal line and the plane (in mils), W represents the line width (in mils), T _Cu Denotes the thickness of the metal (in mils), ε _r Represents the dielectric constant. Z _Diff Is the differential impedance (in ohms), S represents the edge spacing of the traces (in mils), and H represents the total dielectric thickness between the planes (in mils).

As a signal propagates along a transmission line, each step in the path has a corresponding instantaneous impedance. The impedances of the different transmission lines are different, so that when a signal is transmitted from one transmission line to another, the instantaneous impedance of the signal changes, a part of the signal is reflected, and the other part of the signal is distorted and continues to propagate. The larger the impedance difference, the larger the amount of reflected signal. The abrupt change in impedance has a great influence on the distortion of the transmitted signal, which directly causes degradation of the rising edge of the received signal. In order to obtain the optimal signal quality, the utility model relates to a accomplish 2m and above with the antenna to avoid appearing the signal distortion that different instantaneous impedance arouses.

In direct current, the current is uniformly distributed in the signal conductor, and the resistance is as shown in formula 3:

equation 3:

r represents the resistance of the transmission line (in Ω), ρ represents the bulk resistivity of the wire (in Ω · in), Len represents the wire length (in), w represents the line width (in), and t represents the thickness of the wire (in).

At high frequencies, the cross-sectional thickness of the copper conductor through which the current passes is approximately equal to the skin depth δ, as shown in equation 4:

equation 4:

where δ represents the skin depth (in μm) and f represents the sine wave frequency (in GHz). Due to the skin effect, if current flows only through the lower half of the wire, the resistance of the wire is approximated by equation 5:

equation 5:

where R represents line resistance (in Ω), ρ represents volume resistivity of the wire (in Ω · in), Len represents line length (in), w represents line width (in), and δ represents skin depth (in).

Therefore, the equivalent resistance of the transmission line increases with the change of the frequency of the transmission signal, that is, the loss of the signal increases with the increase of the frequency. Therefore, the accurate impedance can be designed to effectively reduce the attenuation of the transmission medium to the signal.

The utility model discloses a select for use polyethylene and/or polytetrafluoroethylene as the substrate of circuit board, optimize the capacitive coupling formula antenna of making the circuit board from two aspects of material property and connected mode simultaneously, guaranteed the stability and the definition of image.

Once the CT inspection apparatus stops, the image of the inspected object 40 is interrupted. The application proposes to adopt an image stitching method, i.e. to combine the images of the detected object 40 before and after the tape is stopped, so as to avoid image interruption. It should be noted that the utility model discloses a capacitive coupling formula antenna can guarantee the stability and the definition of image, provides the technological basis for this method.

Specifically, the CT detection apparatus further includes: an encoder. The encoder is arranged on the transmission belt and moves along with the transmission belt. The encoder is used for gathering the removal data of drive belt to transmit the corresponding relation to the data processing unit, and the removal data includes: the speed of travel and the time of travel of the belt.

The data processing unit is used for determining that the transmission belt is in a belt stop state according to a stop command input from the outside; and splicing the images of the detected object before and after the tape is stopped according to the X-ray signal transmitted by the capacitive coupling antenna, the moving data and the preset tape rewinding time.

Further, the CT detector 30 acquires an X-ray signal corresponding to the first image of the detected object, and transmits the X-ray signal image corresponding to the first image to the data processing unit 90 through the capacitive coupling antenna. The data processing unit 90 determines a first image from the corresponding X-ray signal. The encoder collects movement data of the belt and transmits the movement data to the data processing unit 90, the movement data including: the speed of travel and the time of travel of the belt. The data processing unit 90 determines whether the detected object 40 stops moving according to a stop instruction input from the outside. Upon determining that the detected object 40 stops moving, the data processing unit 90 determines whether the detected object 40 exists within a preset detection range, based on the first image.

When the detected object 40 exists in the preset detection range, the data processing unit 90 controls the driving belt to rewind through the encoder to enable the detected object 40 to leave the preset detection area, then controls the detected object 40 to enter the preset detection area, and obtains a second image of the detected object 40 through the CT detector 30 and the capacitive coupling antenna. Finally, the data processing unit 90 splices the first image and the second image to obtain a complete image of the detected object 40.

When the detected object 40 does not exist in the preset detection range, the data processing unit 90 controls the driving belt to move in the direction close to the radiation source 10 through the encoder.

Example four

The embodiment of the utility model provides a manufacturing method of capacitive coupling formula antenna for the transmitting antenna of preparation embodiment one, including following step:

step 1, selecting a base material.

In the embodiment of the present invention, polyethylene and/or polytetrafluoroethylene are used as the base material.

And 2, determining the thickness and width of the upper copper foil wire, the thickness and width of the lower copper foil wire and the thickness of the base material according to the impedance matching of the flexible circuit.

And 3, attaching the upper copper foil wiring and the lower copper foil wiring to the base material to obtain the circuit board.

And 4, attaching insulating films to the top surface and the ground of the circuit board to obtain the capacitive coupling antenna.

The technical solution of the present application is described in detail below with reference to examples. The utility model discloses a circuit board is flexible circuit board, and this flexible circuit board is 2000mm wide high two-layer flexible circuit board of 1mm, and the communication field is applied to this design, is the antenna that is used for transmitting signal. The antenna needs to transmit signals at a rate of 2.5GBbps, needs to be 2 meters long, and needs to be bent at a certain angle to be matched with equipment for use. The flexible circuit board wires are a pair of differential wires, the differential impedance is 85 ohms, and the top layer wires are copper foils with the width of 6mm and the thickness of 0.1 mm. The distance between the two wires is 1 mm. The intermediate substrate is polyethylene with a thickness of 0.8 mm. The bottom layer is a copper foil with the width of 3cm and the thickness of 0.1 mm.

Step 1, selecting polyethylene as a base material.

Polyethylene (PE) is a thermoplastic resin obtained by polymerizing ethylene, and is typically a soft and tough polymer. The volume resistivity of PE is high, and the dielectric constant and the dielectric loss tangent are small, and are hardly influenced by frequency.

And step 2, determining parameters.

The selection of the material not only needs to consider the impedance, but also needs to fully consider the convenience of material selection. For reasons of manufacturing difficulty and material procurement, 3M industrial tape 9508W was chosen. The industrial adhesive tape is a double-sided adhesive tape and can be used for conveniently pasting a signal transmission line. The industrial adhesive tape has high foam density of 90kg/m ³ The thickness is 0.8 mm. The width of the copper foil conductor for transmitting signals is 6mm, and the thickness is0.1mm.

And 3, assembling the antenna.

The metal copper foil is precisely adhered to an industrial tape as a substrate. The required signal transmission line is obtained. Then, the top and bottom of the circuit are pasted with insulating films.

And 4, testing.

And testing the characteristic impedance and S parameter of the processed flexible circuit by using a network analyzer to determine the quality of the flexible circuit. Through tests, the flexible circuit (with the length of 2m) can achieve high-frequency signals with the transmission rate of 2.5Gbps, namely, the measured signal attenuation is less than 3 dB.

The mature manufacturing process of the existing high-frequency printed circuit board can reach 1.2 meters in length and has no flexibility. The cost of producing a printed circuit 1.2 meters in length is about 2000 dollars. The production requirement of longer high-speed printed circuits and manufacturers jointly develop a new production line and a new process, and the defects of high cost and uncontrollable quality exist.

The utility model provides a high-speed flexible circuit's design method, only need ensure to paste transmission conductor's accuracy just can. The length of the flexible circuit board can be achieved only by measuring and cutting with a measuring ruler, and the flexible circuit board can be made according to product requirements. The used dielectric materials and transmission conductor materials are common materials in the market, have very low cost and are easy to purchase. The cost of the capacitive coupling type antenna produced by the method is lower than 50 yuan.

EXAMPLE five

The utility model discloses a further concrete embodiment discloses a manufacturing method of capacitive coupling formula sliding ring for the capacitive coupling formula sliding ring of preparation embodiment one, including following step:

first, the rotating disc is designed and machined.

And determining the number of the receiving and transmitting devices according to the size of the data volume needing to be transmitted. According to actual conditions, the rotating disc with the corresponding size is designed.

The inner diameter of the rotary disc designed in the embodiment is 1050mm, the outer diameter is 1300mm, and the thickness is 45 mm. The rotating disc is made of metal, such as steel.

A first groove is formed along the periphery of the outer surface of the rotating disc, the width of the first groove is 23mm, and the depth of the first groove is 3 mm.

And a second groove is formed along the circumference of the inner surface of the rotating disc, the width of the second groove is 23mm, and the depth of the second groove is 3 mm. The position of the second groove corresponds to the position of the first groove.

Secondly, a transmitting unit of the outer surface of the rotating disk (2 n-1 group, n is 1, 2, 3 … …) is installed.

Installing a sending end data processing unit on the rotating disc through a positioning hole; the transmitting antenna is fixedly arranged in a first groove on the outer surface of the rotating disk in a sticking mode.

Third, a transmitting unit of the inner surface of the rotating disk (group 2n, n being 1, 2, 3 … …) is installed.

Installing a sending end data processing unit on the rotating disc through a positioning hole; the transmitting antenna is fixedly arranged in a second groove on the outer surface of the rotating disk in a sticking mode.

EXAMPLE six

The utility model discloses a further concrete embodiment discloses a capacitive coupling formula sliding ring's mounting method for install capacitive coupling formula sliding ring of embodiment one, including following step:

first, the rotating disk (rotor end) is mounted on the CT gantry 11, as shown in fig. 7.

Second, a receiving unit (first receiving unit) of the outer surface of the rotating disk (group 2n-1, n being 1, 2, 3 … …) is installed.

The first receiving unit (i.e., the stator end) is secured to the CT gantry. The first receiving unit comprises a receiving end data processing module and a receiving antenna, and the two parts can be integrated on a printed circuit or connected in a plug-in mode. The stator end is located outside the rotor end (rotating disc). The receive antenna and the transmit antenna are perfectly aligned and spaced apart by a distance of 3 mm.

Third, a receiving unit (second receiving unit) of the inner surface of the rotating disk (group 2n, n being 1, 2, 3 … …) is installed.

The second receiving unit (i.e., the stator end) is secured to the CT gantry. The second receiving unit comprises a receiving end data processing module and a receiving antenna, and the two parts can be integrated on a printed circuit or connected in a plug-in mode. The stator end is located inside the rotor end (rotating disk). The receive antenna and the transmit antenna are perfectly aligned and spaced apart by a distance of 3 mm.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the present invention.

Claims (10)

1. A capacitive coupling slip ring is characterized by comprising a disc body, a sending unit and a receiving unit, wherein the sending unit comprises a sending antenna and a sending end data processing unit;

the disc body is hollow and annular, a first groove is circumferentially arranged on the inner surface of the disc body, the shape of the first groove is matched with that of the transmitting antenna, and the transmitting antenna is arranged in the first groove; the outer surface of the tray body is provided with a second groove arranged in the circumferential direction, the shape of the second groove is matched with that of the transmitting antenna, and the transmitting antenna is arranged in the second groove.

2. The capacitively coupled slip ring of claim 1, wherein the location of the first groove and the location of the second groove correspond.

3. Capacitively coupled slip ring according to claim 1 or 2, characterized in that the transmit-side data processing unit comprises a transmit circuit board and a data line, both the transmit antenna and the data line being connected to the transmit circuit board.

4. The capacitively coupled slip ring of claim 3, wherein said transmitting circuit board is fixed to said disc body.

5. The capacitively coupled slip ring of claim 2, wherein the number of first grooves and second grooves is at least 1.

6. The capacitively coupled slip ring of claim 2, wherein the receiving unit comprises a receiving end data processing unit and a receiving antenna.

7. The capacitively coupled slip ring of claim 1, wherein the receiving unit comprises a first receiving unit and a second receiving unit, the first receiving unit being disposed adjacent to an inner surface of the rotating disk.

8. The capacitively coupled slip ring of claim 7, wherein the first receiving unit is 1.5-5mm from the transmitting antenna within the first groove.

9. The capacitively coupled slip ring of claim 1, wherein the transmitting antenna is affixed within the first recess.

10. The capacitively coupled slip ring of claim 1, wherein the transmit antenna is a plurality of transmit antennas that enclose a circle.

Images