Transmission cable assembly and interference signal suppression method of transmission cable assembly

Abstract

The invention relates to a transmission cable assembly and an interference signal suppression method of the transmission cable assembly. A transmission cable is used for realizing transmission of signals received by a radio frequency coil. The transmission cable wave trap is detachably connected with the transmission cable, and the wave trap comprises a first coil and a second coil. The first coil is configured to be in an annular spiral shape, and the transmission cable is sleeved with the first coil. The second coil is also configured to be in an annular spiral shape, the transmission cable is sleeved with the second coil, the rotation direction of the first coil is opposite to that of the second coil, the first coil, the second coil and at least part of the transmission cable can form a resonance circuit, and the resonance circuit is used for restraining interference of external signals on signals received by the radio frequency coil in transmission. According to the transmission cable assembly adopting the structural form, the effect of suppressing common-mode current in the transmission cable is improved, and meanwhile, the wave trap is smaller in size and lighter in weight.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a transmission cable assembly and an interference signal suppression method for the transmission cable assembly. Background Art

[0002] Magnetic resonance imaging (MR) systems can non-invasively obtain images of any section of the human body for doctors to diagnose diseased parts. During MRI scanning, the volume transmit coil (VTC) transmits power, and a large common-mode current is generated on the cable of the local coil, which seriously affects the local radio frequency (B1) field and thus affects the imaging quality. Therefore, in order to suppress this common-mode current, it is necessary to install a notch filter on the cable of the local coil. However, with the continuous development of technology, the number of units in the MRI receiving coil is increasing, which directly leads to the transmission cable becoming thicker and thicker, which brings many challenges to the design of RF notch filters.

[0003] The wave trap in the related art is to wind the transmission cable into a spiral shape, put a shielding cover on the outside, weld one end of the shielding cover directly to the cable, and connect the other end through a tuning capacitor. This wave trap has a large inductance, so it is effective in suppressing common-mode current and generates less heat. However, the disadvantages are that it is large in size and heavy in weight, and it increases the loss of the internal RF line and affects the total phase distance. As the cable becomes thicker, the diameter of the spiral winding also increases, resulting in the wave trap becoming larger and heavier. Summary of the invention

[0004] Based on this, it is necessary to provide a transmission cable assembly and a method for suppressing interference signals of a transmission cable assembly to address the technical problem in the related art that the volume and weight of the trap increase as the diameter of the radio frequency line increases.

[0005] A transmission cable assembly, the transmission cable common mode comprising:

[0006] A transmission cable, used to transmit the signal received by the radio frequency coil;

[0007] A wave trap, detachably connected to the transmission cable, comprising a first coil and a second coil;

[0008] The first coil is constructed in a ring-shaped spiral shape, and the first coil is sleeved on the transmission cable;

[0009] The second coil is also constructed in a ring-shaped spiral shape, and the second coil is sleeved on the transmission cable;

[0010] The first coil and the second coil have opposite rotation directions, and the first coil, the second coil and at least part of the transmission cable can form a resonant circuit, which is used to suppress interference of external signals on the RF coil receiving signal in transmission.

[0011] In one embodiment, the first coil and the second coil respectively form a coil loop, and the coil loops are respectively connected with tuning capacitors;

[0012] Alternatively, the ends of the first coil and the second coil are disconnected.

[0013] In one embodiment, the notch filter further comprises:

[0014] A bracket is provided with an avoidance hole which passes through the bracket, and the transmission cable can pass through the avoidance hole. The first coil and the second coil are wound on the outer peripheral surface of the bracket, and the extension direction of the first coil and the second coil is along the circumferential axis of the bracket.

[0015] In one embodiment, a first limiting groove and a second limiting groove are constructed on the outer circumferential surface of the bracket, the first limiting groove and the second limiting groove extend spirally along the circumferential axis of the bracket, the first limiting groove and the second limiting groove have opposite rotation directions, the first coil is arranged in the first limiting groove, and the second coil is arranged in the second limiting groove.

[0016] In one embodiment, the notch filter further comprises:

[0017] A first printed circuit board is provided with a plurality of first conductive wires and a plurality of second conductive wires, wherein the first conductive wires and the second conductive wires have opposite rotation directions;

[0018] A second printed circuit board is disposed on one side of the first printed circuit board, and a plurality of third conductive wires are disposed on the second printed circuit board, and each of the third conductive wires is electrically connected to the first conductive wire end to end in sequence to form the first coil;

[0019] A third printed circuit board is arranged on the other side of the first printed circuit board, and a plurality of fourth wires are arranged on the third printed circuit board, and each of the fourth wires is electrically connected to the second wire end to end in sequence to form the second coil;

[0020] The first printed circuit board, the second printed circuit board and the third printed circuit board are all provided with through holes, and the transmission cables pass through the through holes.

[0021] In one embodiment, the first printed circuit board includes a first side surface (153) and a second side surface arranged opposite to each other;

[0022] A plurality of first wire grooves and a second wire groove are respectively provided on the first side surface and the second side surface and are spaced apart along the circumference of the through hole, and first wire holes penetrating to the second side surface are provided at both ends of the first wire groove, and second wire holes penetrating to the first side surface are provided at both ends of the second wire groove;

[0023] The first wire is arranged in the first wire slot, and two ends of the first wire pass through the first wire hole and are flush with the second side surface;

[0024] The second wire is arranged in the second wire slot, and two ends of the second wire pass through the second wire hole and are flush with the first side surface;

[0025] The extension directions of two adjacent first wire grooves intersect, the extension directions of two adjacent second wire grooves intersect, and the inclination directions of the first wire groove and the second wire groove are opposite.

[0026] In one embodiment, a plurality of third wire grooves are provided on the side of the second printed circuit board facing away from the first printed circuit board and are spaced apart along the axial direction of the through hole, and third wire holes are provided at both ends of the third wire groove and penetrate to the side of the second printed circuit board facing the first printed circuit board, and the extension directions of two adjacent third wire grooves intersect, and the third wire is provided in the third wire groove, and both ends of the third wire pass through the third wire holes and are flush with the other side of the second printed circuit board;

[0027] Two ends of the third wire are respectively electrically connected to ends of two adjacent first wires that are close to the third wire;

[0028] Wherein, the first wire groove and the third wire groove are inclined in opposite directions.

[0029] In one embodiment, a plurality of fourth wire grooves are provided on one side of the third printed circuit board and are spaced apart along the axial direction of the through hole, and fourth wire holes are provided at both ends of the fourth wire groove and pass through to the side of the third printed circuit board facing the first printed circuit board, and the extension directions of two adjacent fourth wire grooves intersect, and the fourth wire is provided in the fourth wire groove, and both ends of the fourth wire pass through the fourth wire holes and are flush with the other side of the third printed circuit board;

[0030] Two ends of the fourth wire are respectively electrically connected to ends of two adjacent second wires close to the fourth wire;

[0031] Wherein, the second wire groove and the fourth wire groove are inclined in opposite directions.

[0032] A method for suppressing interference signals of a transmission cable assembly,

[0033] The transmission cable assembly includes a transmission cable and a plurality of wave traps sleeved on the outer periphery of the transmission cable;

[0034] The wave trap is detachably connected to the transmission cable and comprises a first coil (110) and a second coil, wherein the first coil and the second coil are both constructed in a ring-shaped spiral and have opposite rotation directions;

[0035] The method comprises:

[0036] Connecting a tuning capacitor to the first coil or the second coil, and adjusting the tuning capacitor so that the first coil, the second coil, the tuning capacitor and the transmission cable form a resonant circuit, wherein the resonant circuit is used to suppress interference of external signals on a signal received by the RF coil during transmission; or,

[0037] The number of spiral turns of the first coil or the second coil is adjusted so that the first coil, the second coil and the transmission cable form a resonant circuit, and the resonant circuit is used to suppress interference of external signals on the radio frequency coil receiving signal in transmission.

[0038] In one embodiment, a plurality of the wave traps are arranged in series along the axis of the transmission cable, and an insulating member is arranged between two adjacent wave traps.

[0039] Transmission cable The beneficial effects of the present invention are:

[0040] The present invention provides a transmission cable assembly, wherein a wave trap is used to be connected to the transmission cable to suppress the common mode current on the transmission cable to reduce the influence on the local radio frequency (B1) field.

[0041] From the perspective of electromagnetic field, the first coil and the second coil are both constructed in a circular spiral shape and have opposite rotation directions. When a common-mode current is generated in the transmission cable, a magnetic field of the same direction distributed along the circumference of the transmission cable will be generated inside the first coil and the second coil. Since the rotation directions are opposite, the current directions on the first coil and the second coil are opposite, so the magnetic fields outside the first coil and the second coil cancel each other out, reducing the impact on the local radio frequency (B1) field, and the magnetic fields inside them are superimposed on each other, generating a current in the axial direction of the cable in the opposite direction to the common-mode current and canceling out the common-mode current. The first coil and the second coil are placed overlapping to form mutual inductance between the first coil and the second coil, thereby dividing the energy coupled from the transmission cable to the trap into two current paths, reducing the heat generated by the trap and making the trap smaller and lighter.

[0042] From the perspective of the circuit, the first coil and the second coil are arranged in a ring-shaped spiral structure, which can be regarded as an inductor, and connected in parallel with the tuning capacitor to form a parallel resonant circuit, generating high impedance. When the trap is set on the transmission cable, the high impedance is applied to the transmission cable through coupling, which can prevent the common mode current from passing through the transmission cable. By utilizing the mutual inductance between the first coil and the second coil, a part of the inductance value exists in the form of mutual inductance, which reduces the heat generation.

[0043] In summary, the above-mentioned wave trap is connected to the transmission cable, and there is no direct electrical connection between the wave trap and the cable, which improves the maintainability, and because the wave trap is evenly distributed on the transmission cable, it improves the effect of suppressing the common mode current in the transmission cable. In addition, because the transmission cable does not need to be wound, the volume of the wave trap is no longer limited by the thickness of the transmission cable, and can be designed to be smaller and lighter. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of the structure of a closed annular spiral coil wave trap provided by an embodiment of the present invention after being inserted into a transmission cable;

[0045] Figure 2 A schematic structural diagram of a closed annular spiral coil wave trap provided by an embodiment of the present invention after being inserted into a transmission cable from another viewing angle;

[0046] Figure 3 A schematic diagram of the structure of a wave trap of a ring-shaped spiral coil with two ends disconnected provided by an embodiment of the present invention after being inserted into a transmission cable;

[0047] Figure 4 A schematic diagram of the structure of a ring-shaped spiral coil with two ends disconnected provided by an embodiment of the present invention;

[0048] Figure 5 A schematic structural diagram of a wave trap of a ring-shaped spiral coil with two ends disconnected provided by an embodiment of the present invention after being inserted into a transmission cable from another viewing angle;

[0049] Figure 6 A schematic diagram of a structure in which a wave trap of a ring-shaped spiral coil with two ends disconnected provided in an embodiment of the present invention is inserted into a transmission cable and a copper foil is arranged outside the wave trap;

[0050] Figure 7 A schematic structural diagram of a wave trap having a closed annular spiral coil and a support provided in one embodiment of the present invention;

[0051] Figure 8 A schematic diagram of the structure of a closed annular spiral coil provided in one embodiment of the present invention having a wave trap with a support after being inserted into a transmission cable;

[0052] Fig. 9 A schematic diagram of the structure of a wave trap having a ring-shaped spiral coil with two ends disconnected and a support provided by an embodiment of the present invention after being inserted into a transmission cable;

[0053] Fig.10 A schematic diagram of the structure of a first printed circuit board in a wave trap provided in an embodiment of the present invention;

[0054] Fig.11 A schematic structural diagram of a first printed circuit board in a wave trap provided by an embodiment of the present invention at a first side perspective;

[0055] Fig.12 A schematic structural diagram of a first printed circuit board in a wave trap provided by an embodiment of the present invention at a second side viewing angle;

[0056] Fig.13 A schematic diagram of the structure of a second printed circuit board in a wave trap provided in an embodiment of the present invention;

[0057] Fig.14 A schematic diagram of the structure of a third printed circuit board in a wave trap provided in an embodiment of the present invention;

[0058] Fig.15 A schematic diagram of the structure of a printed circuit board type wave trap provided by an embodiment of the present invention after being inserted into a transmission cable;

[0059] Fig.16 A schematic diagram of the structure of a closed annular spiral coil wave trap assembly provided by an embodiment of the present invention after being connected to a transmission cable;

[0060] Fig.17 A schematic diagram of the structure of a ring-shaped spiral coil type wave trap assembly with two ends disconnected provided by an embodiment of the present invention after being connected to a transmission cable;

[0061] Fig.18 A schematic diagram of the structure of a wave trap assembly having a closed annular spiral coil and a bracket connected to a transmission cable according to an embodiment of the present invention;

[0062] Fig.19 A schematic diagram of the structure of a wave trap assembly having a ring-shaped spiral coil with two ends disconnected and a bracket provided in one embodiment of the present invention after being connected to a transmission cable;

[0063] Fig. 20 A schematic diagram of the structure of a printed circuit board type wave trap assembly provided by an embodiment of the present invention after being connected to a transmission cable;

[0064] Fig.21 An equivalent circuit diagram of a wave trap 100 provided in one embodiment of the present invention;

[0065] Fig. 22An equivalent circuit diagram of another wave trap 100 provided by an embodiment of the present invention;

[0066] Fig.23 An equivalent circuit diagram of a plurality of wave traps provided on a transmission cable according to an embodiment of the present invention;

[0067] Fig.24 Another equivalent circuit diagram of a transmission cable provided with multiple wave traps according to an embodiment of the present invention.

[0068] Reference numerals:

[0069] The wave trap 100; the first coil 110; the second coil 120; the tuning capacitor 130; the bracket 140; the avoidance hole 141; the first printed circuit board 150; the first wire 151; the second wire 152; the first side 153; the first wire groove 1531; the first wire hole 1532; the second side 154; the second wire groove 1541; the second wire hole 1542; the second printed circuit board 160; the third wire groove 161; the third wire hole 1611; the third printed circuit board 170; the fourth wire groove 171; the fourth wire hole 1711; the transmission cable 200; the insulating member 300; the shielding cover 400. DETAILED DESCRIPTION

[0070] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0071] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0072] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0073] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0075] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0076] See also Figures 1 to 15An embodiment of the present invention provides a transmission cable assembly, which includes a transmission cable and a trap. The transmission cable is used to realize the transmission of a signal received by a radio frequency coil, and the transmission cable can be a DC transmission cable or an AC transmission cable. The trap is detachably connected to the transmission cable, and includes a first coil 110 and a second coil 120. The first coil 110 is constructed in a ring-shaped spiral shape, and the first coil 110 is sleeved on the transmission cable 200; the second coil 120 is also constructed in a ring-shaped spiral shape, and the second coil 120 is sleeved on the transmission cable 200; wherein the first coil 110 and the second coil 120 have opposite rotation directions, and the first coil 110, the second coil 120 and at least part of the transmission cable can form a resonant circuit, and the resonant circuit is used to suppress the interference of external signals on the signal received by the radio frequency coil in transmission, for example, suppressing the common mode current of the transmission cable 200 in the electromagnetic field.

[0077] The transmission cable assembly provided by the present technical solution is explained by taking the transmission cable assembly as a radio frequency cable assembly as an example, wherein the trap 100 is used to be connected to the transmission cable 200 to suppress the common mode current on the transmission cable 200, so as to reduce the influence on the local radio frequency (B1) field. The first coil 110 and the second coil 120 are arranged in a ring-shaped spiral structure, which can be regarded as an inductor, and connected in parallel with the tuning capacitor to form a parallel resonant circuit to generate high impedance. When the trap is set on the transmission cable 200, the high impedance is applied to the transmission cable 200 through coupling, which can hinder the common mode current from passing through the transmission cable. Among them, a resonant circuit can be formed in at least a part of the first coil 110, the second coil 120 and the transmission cable to suppress the common mode current.

[0078] The rotation directions of the first coil 110 and the second coil 120 are set to be opposite, so that when a common-mode current is generated in the transmission cable 200, magnetic fields of the same direction distributed along the circumference of the transmission cable 200 are generated inside the first coil 110 and the second coil 120. Since the rotation directions are opposite, the current directions of the first coil 110 and the second coil 120 are opposite, so the magnetic fields outside the first coil 110 and the second coil 120 cancel each other, reducing the impact on the local radio frequency (B1) field, and the magnetic fields inside them are superimposed on each other, generating a current in the axial direction of the cable in the opposite direction to the common-mode current, which cancels out the common-mode current.

[0079] The first coil 110 and the second coil 120 are placed overlappingly, so that mutual inductance is formed between the first coil 110 and the second coil 120, so that the energy coupled from the transmission cable 200 to the wave trap 100 is divided into two current paths, reducing the heat generated by the transmission cable of the wave trap 100, and making the wave trap 100 smaller and lighter. Therefore, by using the above transmission cable assembly, the effect of suppressing the common mode current in the transmission cable 200 is improved, and the wave trap 100 is made smaller and lighter.

[0080] It is understandable that the inner diameter of the rings formed by the first coil 110 and the second coil 120 can be set according to the diameter of the transmission cable 200. Figure 1 , Figure 2 As shown, when the tuning capacitor 130 is used, the first coil 110 and the second coil 120 respectively form a closed coil with the tuning capacitor 130. The number of the tuning capacitors 130 on the first coil 110 and the second coil 120 can be one, two, three or even more.

[0081] When the tuning capacitor 130 is used, the equivalent circuit of the trap is as follows: Fig.21 As shown, the tuning capacitor C1 on the first coil 110 is connected in parallel with the equivalent inductance L1 in the first coil 110 and the inductance L3 formed by the equivalent coupling mutual inductance between the first coil 110 and the second coil 120; the tuning capacitor C2 in the second coil 120 is connected in parallel with the equivalent inductance L2 in the second coil 120 and the inductance L4 formed by the equivalent coupling mutual inductance between the first coil 110 and the second coil 120. Since the first coil 110 and the second coil 120 intersect, distributed capacitance C3 and distributed capacitance C4 are generated at the intersection. The coupling between the first coil 110 and the transmission cable is represented by the mutual inductance M1 formed by the inductance L1 in the first coil 110 and the inductance L in the transmission cable, the coupling between the second coil 120 and the transmission cable is represented by the mutual inductance M2 formed by the inductance L2 in the second coil 120 and the inductance L in the transmission cable, and the mutual inductance between the two coils is represented by M3 formed by the inductance L3 in the first coil 110 and the inductance L4 in the second coil 120.

[0082] like Figures 3 to 5 As shown, in one embodiment, when no additional tuning capacitor is used and only the distributed capacitance formed between the devices is used, the first coil 110 and the second coil 120 are composed of two annular spiral coils of the same size and opposite rotation directions, wherein the ends of the annular spiral coils are disconnected and do not form a closed loop, and the distributed capacitance between the annular spiral coils is used to form parallel resonance. The annular spiral coils using this structural form, while taking into account the above-mentioned structural characteristics, make the volume no longer constrained by the volume of the tuning capacitor 130, can be further reduced, and greatly reduce the production cost.

[0083] Specifically, when the first coil and the second coil are set in a form in which the ends of the coils are disconnected, the equivalent circuit diagram formed is as follows: Fig. 22 As shown, the difference between this structure and the closed coil is that there is no need to set the tuning capacitor 130 on the first coil 110 and the second coil 120, and the distributed capacitance C3 and distributed capacitance C4 generated by the crossing of the two coils are used to form parallel resonance with the inductances L1 and L3 in the first coil and the inductances L2 and L4 in the second coil 120.

[0084] like Figure 6 As shown, further, in order to reduce the influence of the magnetic field leaked from the spiral coil on the radio frequency field, a shielding cover 400 can be set outside the wave trap 100, thereby further reducing the influence on the local radio frequency (B1) field. The shielding cover 400 can be wrapped with copper foil outside the spiral coil.

[0085] like Figures 7 to 9 As shown, in one embodiment, the wave trap 100 further includes a bracket 140, the bracket 140 is provided with an avoidance hole 141 penetrating the bracket 140, the transmission cable 200 can pass through the avoidance hole 141, the first coil 110 and the second coil 120 are wound on the bracket 140, and the extension direction of the first coil 110 and the second coil 120 is along the circumferential axis of the bracket 140. The first coil 110 and the second coil 120 are wound on the bracket 140 to support the first coil 110 and the second coil 120 through the bracket 140, so that the first coil 110 and the second coil 120 can remain in place, thereby ensuring the stability of the first coil 110 and the second coil 120 being sleeved on the transmission cable 200.

[0086] It is understandable that the support 140 is configured as an annular structure, and the first coil 110 and the second coil 120 are respectively spirally wound on the outer surface of the support 140 along the circumferential axis of the support 140, so that the first coil 110 and the second coil 120 form an annular spiral coil. The first coil 110 and the second coil 120 can be a closed annular spiral coil (such as Figure 8 As shown), it can also be a ring spiral coil with both ends disconnected (as shown Fig. 9 shown).

[0087] Specifically, the outer circumferential surface of the bracket 140 is configured with a first limiting groove and a second limiting groove (not shown in the drawings), the first limiting groove and the second limiting groove extend spirally along the circumferential axis of the bracket 140, the first limiting groove and the second limiting groove have opposite rotation directions, the first coil 110 is arranged in the first limiting groove, and the second coil 120 is arranged in the second limiting groove. By arranging the first limiting groove and the second limiting groove on the bracket 140, and arranging the first coil 110 and the second coil 120 in the first limiting groove and the second limiting groove respectively, the first coil 110 and the second coil 120 are limited. And the first limiting groove and the second limiting groove guide the first coil 110 and the second coil 120 when they are respectively wound on the bracket 140, so that the winding is more convenient.

[0088] It can be understood that the groove shape of the first limiting groove and the second limiting groove can be a square groove or a U-shaped groove.

[0089] In one embodiment, the groove depth of the first limiting groove is greater than the diameter of the first coil 110, and the groove depth of the second limiting groove is greater than the diameter of the second coil 120. The groove depths of the first limiting groove and the second limiting groove are set to be greater than the diameters of the first coil 110 and the second coil 120, so that when the first coil 110 and the second coil 120 are set in the first limiting groove and the second limiting groove, the first coil 110 and the second coil 120 will not be exposed in the first limiting groove and the second limiting groove. In this way, when the bracket 140 is sleeved on the transmission cable 200, the first coil 110 and the second coil 120 will not contact the transmission cable 200, thereby preventing the first coil 110, the second coil 120 and the transmission cable 200 from short-circuiting, thereby ensuring the reliability of the wave trap 100.

[0090] like Figures 10 to 15 As shown, in one embodiment, the wave trap 100 further includes a first printed circuit board 150, a second printed circuit board 160 and a third printed circuit board 170, the first printed circuit board 150 is provided with a plurality of first wires 151 and a plurality of second wires 152, and the first wires 151 and the second wires 152 have opposite rotation directions; the second printed circuit board 160 is arranged on one side of the first printed circuit board 150, and a plurality of third wires are arranged on the second printed circuit board 160, and each third wire is electrically connected to the first wire 151 in sequence end to end to form a first coil 110; the third printed circuit board 170 is arranged on the other side of the first printed circuit board 150, and a plurality of fourth wires are arranged on the third printed circuit board 170, and each fourth wire is electrically connected to the second wire 152 in sequence end to end to form a second coil 120; the first printed circuit board 150, the second printed circuit board 160 and the third printed circuit board 170 are all provided with through holes, and the transmission cable 200 passes through the through holes.

[0091] The second printed circuit board 160 and the third printed circuit board 170 are respectively arranged on both sides of the first printed circuit board 150, and the first wire 151 and the second wire 152 with opposite rotation directions are arranged on the first printed circuit board 150, and the third wire on the second printed circuit board 160 and the first wire 151 are connected end to end in sequence to form the first coil 110; the fourth wire on the third printed circuit board 170 and the second wire 152 are connected end to end in sequence to form the second coil 120. Such an arrangement is conducive to making the wave trap 100 smaller in size, lighter in weight, simpler in manufacturing, and lower in cost, and is conducive to making the first coil 110 and the second coil 120 independent of each other and not affecting each other, thereby improving the effect of suppressing the common mode current in the transmission cable 200.

[0092] like Fig.10 , Fig.11 and Fig.12 As shown, further, the first printed circuit board 150 includes a first side surface 153 and a second side surface 154 that are arranged opposite to each other; a plurality of first wire grooves 1531 and a second wire groove 1541 that are spaced apart along the circumference of the through hole are respectively provided on the first side surface 153 and the second side surface 154, and a first wire hole 1532 that passes through to the second side surface 154 is provided at both ends of the first wire groove 1531, and a second wire hole 1542 that passes through to the first side surface 153 is provided at both ends of the second wire groove 1541; the first conductor 1 51 is arranged in the first wire groove 1531, and the two ends of the first wire 151 pass through the first wire hole 1532 and are flush with the second side surface 154; the second wire 152 is arranged in the second wire groove 1541, and the two ends of the second wire 152 pass through the second wire hole 1542 and are flush with the first side surface 153; wherein, the extension directions of the two adjacent first wire grooves 1531 intersect with each other, and the extension directions of the two adjacent second wire grooves 1541 intersect with each other, and the inclination directions of the first wire groove 1531 and the second wire groove 1541 are opposite.

[0093] A plurality of first wire grooves 1531 and second wire grooves 1541 are respectively provided on the first side surface 153 and the second side surface 154 of the first printed circuit board 150 so as to accommodate the first wire 151 and the second wire 152, thereby facilitating the positioning of the first wire 151 and the second wire 152. First wire holes 1532 penetrating the first printed circuit board 150 are provided at both ends of the first wire groove 1531 so as to facilitate the two ends of the first wire 151 to pass through the first wire hole 1532 to the second side surface, thereby facilitating the electrical connection between the two ends of the first wire 151 and the ends of two different third wires. Accordingly, second wire holes 1542 penetrating the first printed circuit board 150 are provided at both ends of the second wire groove 1541 so as to facilitate the electrical connection between the two ends of the second wire 152 and the ends of two different fourth wires.

[0094] There is no limitation on the structural form of the first wire slot 1531 and the second wire slot, which may be a square slot, a U-shaped slot, etc. The extension directions of the two adjacent first wire slots 1531 are set to intersect, so that the first wire 151 disposed in the first wire slot 1531 is connected to the third wire on the second printed circuit board 160 to form a spiral-shaped coil. Correspondingly, the extension directions of the two adjacent second wire slots 1541 are set to intersect, so that the second wire 152 disposed in the second wire slot 1541 is connected to the fourth wire on the third printed circuit board 170 to form a spiral-shaped coil. The inclination directions of the first wire slot 1531 and the second wire slot 1541 are set to be opposite, so as to realize that the rotation directions of the first coil 110 and the second coil 120 are opposite.

[0095] It can be understood that the first printed circuit board 150 is an annular sheet structure, and the first wire holes 1532 provided at both ends of the first wire groove 1531 and the second wire holes provided at both ends of the second wire groove are respectively provided at positions adjacent to the inner side wall and the outer side wall of the first printed circuit board 150, so as to fix the ends of the first wire 151 and the second wire 152. Further, the groove depth of the first wire groove 1531 and the second wire groove is greater than the diameter of the first wire 151 and the second wire 152, so that the first wire 151 and the second wire 152 are not exposed from the first wire groove 1531 and the second wire groove 1541, so that the second printed circuit board 160 and the third printed circuit board 170 can be attached to the first side surface 153 and the second side surface 154 of the first printed circuit board 150, thereby making the structure of the wave trap 100 more compact and smaller in size.

[0096] In one embodiment, a plurality of third wire grooves 161 are provided on the side of the second printed circuit board 160 facing away from the first printed circuit board 150 and are distributed at intervals along the axial direction of the through hole. Third wire holes 1611 are provided at both ends of the third wire groove 161 and penetrate to the side of the second printed circuit board 160 facing the first printed circuit board 150. The extension directions of two adjacent third wire grooves 161 intersect. The third wire is arranged in the third wire groove 161. The two ends of the third wire pass through the third wire hole 1611 and are flush with the other side of the second printed circuit board 160. The two ends of the third wire are respectively electrically connected to the ends of the two adjacent first wires 151 close to the third wire. The inclination directions of the first wire groove 1531 and the third wire groove 161 are opposite.

[0097] Through the above structure, the third wire is positioned through the third wire slot 161, and the two ends of the third wire are electrically connected to different first wires 151 to form the first coil 110. The first wire slot 1531 and the third wire slot 161 are inclined in opposite directions, so that the first wire 151 and the third wire are connected to form a spiral-shaped first coil 110.

[0098] It can be understood that the depth of the third wire groove 161 is greater than the diameter of the third wire, so that the third wire is not exposed in the third wire groove 161. The two ends of the first wire 151 and the third wire are electrically connected by welding. The third wire holes 1611 located at the two ends of the third wire groove 161 correspond to the positions of the first wire holes 1532 on the two first wire grooves 1531 adjacent to the third wire groove 161, so that the end of the third wire arranged in the third wire hole 1611 can be connected with the end of the first wire 151 arranged in the first pipeline hole, thereby facilitating welding. In one embodiment, the third wire hole 1611 is arranged between the inner side wall and the outer side wall of the second printed circuit board 160; in another embodiment, the third wire hole 1611 can be set as a notch that is recessed from the inner side wall of the second printed circuit board 160 to the outer side wall, or a notch that is recessed from the outer side wall of the second printed circuit board 160 to the inner side wall. The latter method allows the end of the third wire to be exposed to the second printed circuit board 160, thereby facilitating welding.

[0099] In one embodiment, a plurality of fourth wire grooves 171 are provided on the side of the third printed circuit board 170 facing away from the first printed circuit board 150 and are distributed at intervals along the axial direction of the through hole. Fourth wire holes 1711 are provided at both ends of the fourth wire groove 171 and penetrate to the side of the third printed circuit board 170 facing the first printed circuit board 150. The extension directions of two adjacent fourth wire grooves 171 intersect. The fourth wire is arranged in the fourth wire groove 171. The two ends of the fourth wire pass through the fourth wire hole 1711 and are flush with the other side of the third printed circuit board 170. The two ends of the fourth wire are respectively electrically connected to the ends of the two adjacent second wires 152 close to the fourth wire. The inclination directions of the second wire groove and the fourth wire groove 171 are opposite.

[0100] Through the above structure, the fourth wire is positioned through the fourth wire slot 171, and the two ends of the fourth wire are electrically connected to different second wires 152 to form the second coil 120. The second wire slot and the fourth wire slot 171 are inclined in opposite directions, so that the second wire 152 and the fourth wire are connected to form a spiral-like second coil 120.

[0101] It can be understood that the groove depth of the fourth wire groove 171 is greater than the diameter of the fourth wire, so that the fourth wire is not exposed in the fourth wire groove 171. The two ends of the second wire 152 and the fourth wire are electrically connected by welding. The fourth wire holes 1711 located at the two ends of the fourth wire groove 171 correspond to the positions of the second wire holes on the two second wire grooves adjacent to the fourth wire groove 171, so that the end of the fourth wire arranged in the fourth wire hole 1711 can be connected with the end of the second wire 152 arranged in the second pipeline hole, thereby facilitating welding. In one embodiment, the fourth wire hole 1711 is arranged between the inner side wall and the outer side wall of the third printed circuit board 170; in another embodiment, the fourth wire hole 1711 can be set as a notch that is recessed from the inner side wall of the third printed circuit board 170 to the outer side wall, or a notch that is recessed from the outer side wall of the third printed circuit board 170 to the inner side wall. The latter method is adopted, so that the end of the fourth wire can be exposed to the third printed circuit board 170, thereby facilitating welding.

[0102] An embodiment of the present invention further provides a method for suppressing interference signals of a transmission cable assembly.

[0103] The transmission cable assembly includes a transmission cable and a plurality of wave traps 100 sleeved on the outer periphery of the transmission cable;

[0104] The wave trap 100 is detachable and has no electrical connection with the transmission cable 200. The wave trap 100 includes a first coil 110 and a second coil 120. The first coil 110 and the second coil 120 are both constructed in a ring-shaped spiral and have opposite rotation directions.

[0105] Interference signal suppression methods include:

[0106] Connecting a tuning capacitor to the first coil 110 or the second coil 120, and adjusting the tuning capacitor 130 so that the first coil 110, the second coil 120, the tuning capacitor and the transmission cable form a resonant circuit, which is used to suppress interference of external signals on the RF coil receiving signal in transmission;

[0107] Alternatively, the number of spiral turns of the first coil 110 or the second coil 120 is adjusted so that the first coil 110, the second coil 120 and the transmission cable form a resonant circuit, which is used to suppress the interference of external signals on the RF coil receiving signal in transmission. In one embodiment, when the tuning capacitor 130 uses a lumped capacitor, the tuning capacitor 130 is connected to the first coil 110 and the second coil 120 to form a closed loop, and the capacitance value of the tuning capacitor 130 is adjusted to cause the transmission cable to resonate, which is used to suppress common mode current.

[0108] In one embodiment, when the tuning loop uses only distributed capacitance, the number of spiral turns of the first coil 110 or the second coil 120 is adjusted so that the distributed capacitance between the first coil 110, the second coil 120 and the metal conductors of the transmission cable forms resonance, and the resonant loop is used to suppress common mode current.

[0109] Analyze its principle from the perspective of electromagnetic field:

[0110] The first coil 110 and the second coil 120 are both constructed in a ring spiral shape and have opposite rotation directions. When a common-mode current is generated in the transmission cable, magnetic fields in the same direction distributed along the circumference of the transmission cable 200 are generated inside the first coil 110 and the second coil 120. Since the rotation directions are opposite, the current directions on the wires are opposite. Therefore, the magnetic fields outside the first coil 110 and the second coil 120 cancel each other, reducing the impact on the local radio frequency (B1) field, and the magnetic fields inside them are superimposed on each other, generating a current in the opposite direction to the common-mode current in the axial direction of the cable, which cancels out the common-mode current.

[0111] Analyze its principle from the perspective of circuit:

[0112] The first coil and the second coil are arranged in a ring-shaped spiral structure, which can be regarded as an inductor, and connected in parallel with the tuning capacitor to form a parallel resonant circuit, generating high impedance. When the trap is set on the transmission cable, the high impedance is applied to the transmission cable through coupling, which can prevent the common mode current from passing through the transmission cable. By utilizing the mutual inductance between the first coil and the second coil, a part of the inductance value exists in the form of mutual inductance, which reduces the heat generation.

[0113] Two tuning methods:

[0114] like Figure 1 and Fig.21 As shown, by arranging tuning capacitors on the first coil and the second coil, the tuning capacitor C1 on the first coil is connected in parallel with the equivalent inductance L1 on the first coil and the equivalent coupling mutual inductance between the first coil 110 and the second coil 120; the tuning capacitor C2 on the second coil 120 is connected in parallel with the equivalent inductance L2 on the second coil and the inductance L4 formed by the equivalent coupling mutual inductance between the first coil 110 and the second coil 120; since the two coils are arranged in an overlapping manner, distributed capacitance C3 and distributed capacitance C4 are generated at the overlapping portion, and a parallel resonant circuit is formed by utilizing the distributed capacitance C3 and distributed capacitance C4 and the coupling mutual inductance formed in the first coil and the coupling mutual inductance formed in the second coil, thereby generating a high impedance to suppress the common mode current.

[0115] Or, if Figure 3 and Fig. 22 As shown, the number of spiral turns of the first coil 110 or the second coil 120 is adjusted, or the relative position of the disconnection point is changed, and the inductances L1 and L2 and the distributed capacitances C3 and C4 in the equivalent circuit are changed. The distributed capacitances C3 and C4 generated between the metal conductors of the first coil 110 and the second coil 120, the inductances L1 and L3 formed in the first coil, and the inductances L3 and L4 formed in the second coil form a parallel resonant circuit to generate high impedance to suppress common mode current.

[0116] When a plurality of wave traps 100 are arranged in series along the axis of the transmission cable, an equivalent circuit formed on the transmission cable assembly is as follows: Fig.23 and Fig.24 As shown, the electrical relationship between the traps is series connection.

[0117] like Figures 16 to 20 As shown, in one embodiment, a plurality of wave traps 100 are arranged in series along the axis of the transmission cable 200, and an insulating member 300 is arranged between two adjacent wave traps.

[0118] Specifically, the insulating member 300 is provided with a mounting hole, and an insulating member 300 is provided on both sides of each wave trap 100, and multiple wave traps 100 are arranged at intervals along the axis of the transmission cable 200. By providing multiple wave traps 100, multiple wave traps 100 are arranged at intervals along the axis direction of the transmission cable 200. In this way, the transmission cable assembly has good common-mode suppression capability, less heat generation, can be applied to different types of transmission cables 200, and can be completely disassembled and easily installed on any transmission cable 200 without affecting any coil parameters, which is convenient for manufacturing and debugging. The insulating member 300 is provided between two adjacent wave traps 100, and the two adjacent wave traps 100 can be isolated to prevent short circuits between the wave traps 100. Doing so can also disperse energy in multiple wave traps 100 to reduce the heat generation of a single wave trap 100, and even if individual wave traps 100 are damaged, it will not affect the suppression effect of common-mode current. The above structure has the advantages of reducing the heat generated by a single trap 100 and ensuring the suppression effect on the common mode current.

[0119] It can be understood that, in this embodiment, the wave trap 100 can be a wave trap 100 without a support 140, wherein the spiral coil can be (eg Fig.16 The closed toroidal coil shown in FIG. Fig.17 Of course, the wave trap 100 may also be a wave trap 100 provided with a bracket 140, and the spiral coil may be (as shown in FIG. Fig.18 The closed annular spiral coil shown in FIG. Fig.19 The wave trap 100 can also be a ring-shaped spiral coil with two ends disconnected. Fig. 20 1. A printed circuit board type trap 100 is shown.

[0120] The technical features of the above-described embodiments of the transmission cable common mode can be arbitrarily combined. In order to make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A transmission cable assembly, characterized in that: include: A transmission cable, used to transmit the signal received by the radio frequency coil; A wave trap, detachably connected to the transmission cable, comprising a first coil and a second coil; The first coil is constructed in a ring-shaped spiral shape, and the first coil is sleeved on the transmission cable; The second coil is also constructed in a ring-shaped spiral shape, and the second coil is sleeved on the transmission cable; The first coil and the second coil have opposite rotation directions, and the first coil, the second coil and at least part of the transmission cable can form a resonant circuit, which is used to suppress interference of external signals on the RF coil receiving signal in transmission.

2. The transmission cable assembly according to claim 1, characterized in that The first coil and the second coil respectively form a coil loop, and the coil loops are respectively connected with tuning capacitors; Alternatively, the ends of the first coil and the second coil are disconnected.

3. The transmission cable assembly according to claim 1, characterized in that: The notch filter also includes: A bracket is provided with an avoidance hole which passes through the bracket, and the transmission cable can pass through the avoidance hole. The first coil and the second coil are wound on the outer peripheral surface of the bracket, and the extension direction of the first coil and the second coil is along the circumferential axis of the bracket.

4. The transmission cable assembly according to claim 3, characterized in that: A first limiting groove and a second limiting groove are configured on the outer circumferential surface of the bracket. The first limiting groove and the second limiting groove extend spirally along the circumferential axis of the bracket. The first limiting groove and the second limiting groove have opposite rotation directions.

5. The transmission cable assembly according to claim 1, characterized in that: The notch filter also includes: A first printed circuit board is provided with a plurality of first conductive wires and a plurality of second conductive wires, wherein the first conductive wires and the second conductive wires have opposite rotation directions; A second printed circuit board is disposed on one side of the first printed circuit board, and a plurality of third conductive wires are disposed on the second printed circuit board, and each of the third conductive wires is electrically connected to the first conductive wire end to end in sequence to form the first coil; A third printed circuit board is arranged on the other side of the first printed circuit board, and a plurality of fourth wires are arranged on the third printed circuit board, and each of the fourth wires is electrically connected to the second wire end to end in sequence to form the second coil; The first printed circuit board, the second printed circuit board and the third printed circuit board are all provided with through holes, and the transmission cables pass through the through holes.

6. The transmission cable assembly according to claim 5, characterized in that: The first printed circuit board comprises a first side surface and a second side surface which are arranged opposite to each other; A plurality of first wire grooves and a second wire groove are respectively provided on the first side surface and the second side surface and are spaced apart along the circumference of the through hole, and first wire holes penetrating to the second side surface are provided at both ends of the first wire groove, and second wire holes penetrating to the first side surface are provided at both ends of the second wire groove; The first wire is arranged in the first wire slot, and two ends of the first wire pass through the first wire hole and are flush with the second side surface; The second wire is arranged in the second wire slot, and two ends of the second wire pass through the second wire hole and are flush with the first side surface; The extension directions of two adjacent first wire grooves intersect, the extension directions of two adjacent second wire grooves intersect, and the inclination directions of the first wire groove and the second wire groove are opposite.

7. The transmission cable assembly according to claim 6, characterized in that: A plurality of third wire grooves are provided on one side of the second printed circuit board and are spaced apart along the axial direction of the through hole. Third wire holes are provided at both ends of the third wire groove and pass through to the other side of the second printed circuit board. The extension directions of two adjacent third wire grooves intersect. The third wire is provided in the third wire groove. Both ends of the third wire pass through the third wire holes and are flush with the other side of the second printed circuit board. Two ends of the third wire are respectively electrically connected to ends of two adjacent first wires that are close to the third wire; Wherein, the first wire groove and the third wire groove are inclined in opposite directions.

8. The transmission cable assembly according to claim 6, characterized in that: A plurality of fourth wire grooves are provided on one side of the third printed circuit board and are spaced apart along the axial direction of the through hole. Fourth wire holes are provided at both ends of the fourth wire groove and pass through to the other side of the third printed circuit board. The extension directions of two adjacent fourth wire grooves intersect. The fourth wire is provided in the fourth wire groove. Both ends of the fourth wire pass through the fourth wire holes and are flush with the other side of the third printed circuit board. Two ends of the fourth wire are respectively electrically connected to ends of two adjacent second wires close to the fourth wire; Wherein, the second wire groove and the fourth wire groove are inclined in opposite directions.

9. A method for suppressing interference signals of a transmission cable assembly, characterized in that: The transmission cable assembly includes a transmission cable and a plurality of wave traps sleeved on the outer periphery of the transmission cable; The wave trap is detachably connected to the transmission cable, and comprises a first coil and a second coil, wherein the first coil and the second coil are both constructed in a ring-shaped spiral and have opposite rotation directions; The method comprises: Connecting a tuning capacitor to the first coil or the second coil, and adjusting the tuning capacitor so that the first coil, the second coil, the tuning capacitor and the transmission cable form a resonant circuit, wherein the resonant circuit is used to suppress interference of external signals on a signal received by the RF coil during transmission; or, The number of spiral turns of the first coil or the second coil is adjusted so that the first coil, the second coil and the transmission cable form a resonant circuit, and the resonant circuit is used to suppress interference of external signals on the radio frequency coil receiving signal in transmission.

10. The interference signal suppression method of a transmission cable assembly according to claim 9, characterized in that: A plurality of wave traps are arranged in series along the axis of the transmission cable, and an insulating member is arranged between two adjacent wave traps.

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