Method for isolating transmission lines for RF power amplifiers and transmission structure

Abstract

The present invention discloses a method and structure for isolating transmission lines for RF power amplifiers, which includes the steps of: setting the distance between two adjacent transmission lines on a chip substrate to be greater than 2.5 times the width of the transmission lines, providing shield lines on the corresponding inner and outer sides of the transmission lines, covering the outer wall of the transmission line with a permalloy film, covering the outer wall of the permalloy film with an aluminum film, and providing a plurality of grooves on the outer wall of the aluminum film at intervals, each groove being recessed inward and having an inverted triangular structure. The present invention can enhance the degree of isolation between two adjacent transmission lines, enhance the degree of isolation between the transmission lines and the outside, and avoid the interference of parasitic capacitance, induced magnetic field, and external electromagnetic waves with the RF signal transmitted by the transmission line.

Description

[Technical field]

[0001] The present invention relates to the technical field of wireless communication, and in particular to an isolation method and transmission structure for a transmission line for an RF power amplifier. [Background technology]

[0002] Wireless communication is a long-distance transmission communication that transmits between multiple nodes without using conductors or cables, and can be used for radio receivers, radios, etc. In wireless communication, RF power amplifiers are one of the important devices, and their main role is to amplify RF signals, thereby improving the quality of communication.

[0003] However, when conventional RF power amplifiers are actually operated, the degree of isolation between the transmission lines on the chip substrate is poor, and interference is likely to occur between the transmission lines. In addition, external electromagnetic waves may also cause interference in the transmission lines, which may cause interference in the RF signals transmitted inside the transmission lines, and may further affect communication quality. Summary of the Invention [Problem to be solved by the invention]

[0004] An objective of the embodiments of the present invention is to provide a method and a transmission structure for isolating transmission lines for RF power amplifiers, so as to solve the problem that the isolation degree of the transmission lines for RF power amplifiers on the conventional chip substrate is poor, which affects the communication quality. [Means for solving the problem]

[0005] According to a first aspect, an embodiment of the present invention comprises: setting a distance between two adjacent transmission lines on a chip substrate to be greater than 2.5 times the width of the transmission lines, and providing shield lines on the corresponding inner and outer sides of the transmission lines; coating an outer wall of the transmission line with a permalloy coating; and coating an outer wall of the permalloy film with an aluminum film, and providing a plurality of spaced grooves in the outer wall of the aluminum film, the grooves being recessed inward and having an inverted triangular structure.

[0006] Preferably, the depths of the plurality of grooves are equal and smaller than the thickness of the aluminum coating, and the plurality of grooves are provided at equal intervals on the outer wall of the aluminum coating.

[0007] Preferably, the step of coating the outer wall of the transmission line with a permalloy coating specifically includes the steps of: measuring the length of the transmission line and determining that as the length of the permalloy film; measuring the circumference of the transmission line and determining the width of the permalloy film; cutting a portion of the permalloy film corresponding to the transmission line from a permalloy material based on a length and a width of the permalloy film; and a sub-step of uniformly applying an insulating adhesive to one side of the permalloy film, and coating and fixing the side of the permalloy film to which the insulating adhesive has been applied to an outer wall of the transmission line.

[0008] Preferably, the material of the insulating adhesive is 2025DSI, and the thickness of the permalloy film is 40 μm to 50 μm.

[0009] Preferably, after the step of covering and fixing the side of the permalloy coating on which the insulating adhesive is applied to the outer wall of the transmission line, The method further includes the step of placing the transmission line, with the permalloy coating coated and secured thereto, in a high temperature oven and heating the same to 150° C., and then removing the same.

[0010] Preferably, the step of coating the outer wall of the permalloy film with an aluminum film specifically includes the steps of: measuring the length of the transmission line and determining that as the length of the aluminum coating; a sub-step of measuring the circumference of the permalloy film and determining the circumference as the width of the aluminum film; a sub-step of cutting the aluminum film corresponding to the permalloy film from an aluminum material based on a length and a width of the aluminum film; and a sub-step of uniformly applying an insulating adhesive to one side of the aluminum film, and coating the side of the aluminum film to which the insulating adhesive is applied on the outer wall of the permalloy film.

[0011] Preferably, the material of the insulating adhesive is 2025DSI, and the thickness of the aluminum film is 35 μm to 45 μm.

[0012] Preferably, after the step of coating the side of the aluminum coating, on which the insulating adhesive is applied, on the outer wall of the permalloy coating, the method further includes the step of placing the transmission line, which has been coated with the aluminum coating and fixed, in a high-temperature oven, heating it to 150° C., and then removing it.

[0013] Preferably, the depth of the groove is 20 μm to 25 μm, and the distance between two adjacent grooves is 0.5 mm to 0.8 mm.

[0014] Preferably, the shield wire is made of an insulating material, the width of the shield wire is 50 μm to 55 μm, and the length is equal to or greater than the length of the transmission line.

[0015] According to a second aspect, an embodiment of the present invention further provides a transmission structure of an RF power amplifier, comprising: a chip substrate; and at least two transmission lines provided on the chip substrate, wherein a distance between two adjacent transmission lines is greater than 2.5 times the width of the transmission lines; shielding lines are provided on corresponding inner and outer sides of the transmission lines; an outer wall of the transmission lines is coated with the permalloy film; an outer wall of the permalloy film is coated with an aluminum film; and a plurality of grooves, recessed inward and having an inverted triangular structure, are provided at intervals on the outer wall of the aluminum film.

[0016] Compared with the prior art, the method for separating transmission lines for RF power amplifiers of the present invention sets the distance between two adjacent transmission lines on a chip substrate to be greater than 2.5 times the width of the transmission lines, provides shield lines on both opposing sides of the transmission lines, then covers the outer wall of the transmission lines with a permalloy film, further covers the outer wall of the permalloy film with an aluminum film, and provides a plurality of inverted triangular grooves at intervals on the outer wall of the aluminum film. As a result, the predetermined distance between the two adjacent transmission lines and the configuration of the shield lines enhance the degree of separation between the two transmission lines, and reduce the effect of the parasitic capacitance between the transmission lines on the RF signal transmitted by the transmission lines. By covering with the permalloy film, it is possible to avoid the interference of the induced magnetic field existing between the two adjacent transmission lines with the RF signal transmitted inside the transmission lines, and further enhance the degree of separation between the two transmission lines. By covering with the permalloy film and providing the grooves, it is possible to avoid the interference of external electromagnetic waves with the RF signal transmitted inside the transmission lines, and enhance the degree of separation between the transmission lines and the outside.

[0017] In order to more clearly describe the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings necessary for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative labor. [Brief description of the drawings]

[0018] [Figure 1] 4 is a flowchart of a method for isolating a transmission line for an RF power amplifier according to an embodiment of the present invention. [Diagram 2] 4 is a flowchart of sub-steps of step S200 according to an embodiment of the present invention. [Diagram 3] 10 is a flowchart of sub-steps of step S300 according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram of a transmission structure of a first RF power amplifier according to an embodiment of the present invention. [Diagram 5] FIG. 4 is a schematic diagram of a transmission structure of a second RF power amplifier according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The technical solutions of the embodiments of the present invention are described below clearly and fully, but it is obvious that the described embodiments are only some of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present invention.

[0020] The embodiment of the present invention provides a method for isolating a transmission line 2 for an RF power amplifier, which includes steps S100 to S300, as shown in FIG. 1 and FIG.

[0021] S100: The distance between two adjacent transmission lines 2 on a chip substrate 1 is set to be greater than 2.5 times the width of the transmission lines 2, and shield lines 3 are provided on the inner and outer sides of the transmission lines 2 that correspond to each other.

[0022] Here, if the cross section of the transmission line 2 is rectangular, its width is the length of the long side of the rectangle, if the cross section of the transmission line 2 is circular, its width is the diameter of the circle, and if the cross section of the transmission line 2 has another shape, its width is the average number of the distances between the two closest points and the two furthest points.

[0023] When setting, the distance between two adjacent transmission lines 2 on the chip substrate 1 is set, and then when mounting, they are mounted at a predetermined distance.

[0024] Specifically, the increment of the distance between two adjacent transmission lines 2 is set based on the manufacturing process of the factory of the chip substrate 1. Preferably, the distance between two adjacent transmission lines 2 is equal to three times the width (line width) of the transmission lines 2.

[0025] Specifically, the corresponding inner and outer sides of the transmission line 2 are based on the chip substrate 1 .

[0026] Specifically, shield lines 3 are provided on both the inner and outer sides of the respective transmission lines 2 of the RF power amplifier on the chip substrate 1, which correspond to each other.

[0027] Specifically, depending on the layout and spatial size of the chip substrate 1, the shield wire 3 may be provided on the outer wall of the transmission line 2, or may be provided at a position on the chip substrate 1 corresponding to the inside and outside of the transmission line 2.

[0028] Specifically, the shield wire 3 is made of an insulating material and has a length equal to or greater than that of the transmission line 2 .

[0029] Specifically, the width of the shield wire 3 is 50 μm to 55 μm. Of course, the width can be adjusted appropriately according to actual needs.

[0030] Here, if the cross-section of the shielded wire 3 is rectangular, its width is the length of the long side of the rectangle. If the cross-section of the shielded wire 3 is circular, its width is the diameter of the circle. If the cross-section of the shielded wire 3 has another shape, its width is the average number of the distances between the two nearest points and the two farthest points.

[0031] By setting the distance between two adjacent transmission lines 2 on a chip substrate 1 to be greater than 2.5 times the width of the transmission lines 2 and providing insulating shield lines 3 on the corresponding inner and outer sides of the transmission lines 2, the two adjacent transmission lines 2 are separated from each other, the degree of isolation between the two transmission lines 2 is enhanced, and the effect of the parasitic capacitance between the two transmission lines 2 on the RF signal transmitted by the transmission lines 2 is reduced.

[0032] S200: The outer wall of the transmission line 2 is coated with a permalloy film 4.

[0033] Specifically, in step S200, the outer wall of each of the transmission lines 2 is coated with the permalloy film 4, so that the outer wall of each of the transmission lines 2 is coated with the permalloy film 4.

[0034] Specifically, as shown in FIG. 2, step S200 includes the following steps: A sub-step S201 of measuring the length of the transmission line 2 and setting it as the length of the permalloy film 4; a sub-step S202 of measuring the circumference of the transmission line 2 and setting it as the width of the permalloy film 4; a sub-step S203 of cutting the permalloy film 4 corresponding to the transmission line 2 from a permalloy material based on the length and width of the permalloy film 4; and sub-step S204 of uniformly applying an insulating adhesive to one side of the permalloy film 4, and covering and fixing the side of the permalloy film 4 to which the insulating adhesive has been applied to the outer wall of the transmission line 2.

[0035] Here, steps S201 to S204 are steps for covering the outer wall of the single transmission line 2 with the permalloy coating 4.

[0036] The length and circumference of the transmission line 2 are measured by a measuring tool, or are directly obtained according to the parameters when manufacturing the chip substrate 1. When cutting, a corresponding cutting tool can be used for cutting.

[0037] Specifically, the material of the insulating adhesive is 2025DSI, and the thickness of the permalloy film 4 is 40 μm to 50 μm. Of course, insulating adhesives made of other materials may be selected according to actual needs, and the thickness may be adjusted appropriately.

[0038] Specifically, after step S204, the method further includes a step of heating the transmission line 2 covered and fixed with the permalloy film 4 in a high-temperature oven to 150° C. and then removing the same. Here, the method does not remove the transmission line 2 unless the insulating adhesive is completely melted and fully fused with the permalloy film 4 and the transmission line 2 after heating to 150° C. This can improve the stability and strength of the connection between the permalloy film 4 and the transmission line 2.

[0039] Specifically, the step of heating the chip substrate 1 in a high-temperature oven is performed after the outer wall of each of the transmission lines 2 is coated with the permalloy film 4 .

[0040] Since the permalloy coating 4 is a material with high magnetic permeability, by adding the permalloy coating 4 to the outer wall of the transmission line 2, when an RF signal passes through the two transmission lines 2 and an induced magnetic field is present, the magnetic field generated by the induced magnetic field moves along the outer surface layer of the permalloy coating 4, and no induced current is formed inside the transmission line 2. As a result, there is no interference with the RF signal transmitted inside the transmission line 2, and the degree of separation between the two transmission lines 2 is improved.

[0041] S300: The outer wall of the permalloy film 4 is covered with an aluminum film 5, and a plurality of grooves 51 are provided at intervals on the outer wall of the aluminum film 5, each groove being recessed inward and having an inverted triangular structure.

[0042] Specifically, in the step S300, the outer wall of each of the transmission lines 2 is covered with the permalloy film 4 after the insulating adhesive in the step S200 has cooled and solidified.

[0043] Specifically, in the step 300 , the outer wall of each of the permalloy films 4 is coated with the aluminum film 5 , so that the aluminum film 5 is coated on each of the transmission lines 2 .

[0044] Specifically, as shown in FIG. 3, step 300 includes the following steps: A sub-step S301 of measuring the length of the transmission line 2 and setting the measured length as the length of the aluminum film 5; a sub-step S302 of measuring the perimeter of the permalloy film 4 and setting it as the width of the aluminum film 5; a sub-step S303 of cutting the aluminum film 5 corresponding to the permalloy film 4 from an aluminum material based on the length and width of the aluminum film 5; and sub-step S304 of uniformly applying an insulating adhesive to one side of the aluminum film 5 and covering the side of the aluminum film 5 to which the insulating adhesive is applied on the outer wall of the permalloy film 4.

[0045] Here, steps 301 to 304 are steps for covering the outer wall of the single permalloy film 4 with the aluminum film 5.

[0046] The length of the transmission line 2 has already been measured in step S201, so it can be obtained without measuring here, and the circumference of the permalloy coating 4 is the width of the permalloy coating 4, which has already been measured in step S202, so it can be obtained without measuring here.

[0047] Specifically, the material of the insulating adhesive is 2025DSI, and the thickness of the aluminum film 5 is 35 μm to 45 μm. Of course, insulating adhesives made of other materials may be selected according to actual needs, and the thickness may be adjusted appropriately.

[0048] Specifically, after step S304, the method further includes a step of placing the transmission line 2, which is covered and fixed with the aluminum film 5, in a high-temperature oven, heating it to 150° C., and then removing it. Here, the method does not remove the transmission line 2 unless the insulating adhesive is completely melted and fully fused with the permalloy film 4 and the aluminum film 5 after heating it to 150° C. This can improve the stability and strength of the connection between the permalloy film 4 and the aluminum film 5.

[0049] Specifically, the step of heating the chip substrate 1 in a high-temperature oven is performed after the outer walls of the permalloy films 4 are covered with the aluminum films 5 .

[0050] Specifically, the grooves 51 are provided after the aluminum film 5 is cut in step S303, and the step S304 is performed after the grooves 51 are provided.

[0051] Specifically, the depths of the plurality of grooves 51 are equal and smaller than the thickness of the aluminum coating 5 , and the plurality of grooves 51 are provided on the outer wall of the aluminum coating 5 at equal intervals.

[0052] Specifically, the depth of the groove 51 is 20 μm to 25 μm, and the distance between two adjacent grooves 51 is 0.5 mm to 0.8 mm.

[0053] The outer wall of the permalloy coating 4 is covered with the aluminum coating 5, and a plurality of grooves 51 are provided on the outer surface of the aluminum coating 5, each groove being recessed inward and having an inverted triangular structure. This makes it possible for the aluminum coating 5 to separate external electromagnetic waves. Furthermore, when external electromagnetic waves enter the groove 51 having an inverted triangular structure, the two slopes of the groove 51 having an inverted triangular structure reflect the electromagnetic waves, causing the electromagnetic waves at the two slopes to cancel each other out, thereby preventing the external electromagnetic waves from interfering with the RF signal transmitted inside the transmission line 2, and thereby improving the degree of separation between the transmission line 2 and the outside.

[0054] In the above embodiment, after steps S100 to S300 are completed, the transmission line 2 is attached to the chip substrate 1. In this case, the outermost aluminum film 5 of the transmission line 2 is attached to the chip substrate 1 by a method such as adhesion or welding.

[0055] Also, if it is necessary to provide the shield wire 3 on the chip substrate 1, the step S100 can be performed after the steps S200 and S300 are completed. In such a case, first, the outer wall of the permalloy film 4 is coated with the aluminum film 5, and then the transmission line 2 is coated with the permalloy film 4.

[0056] Of course, according to actual needs, after completing step S100, as shown in FIG. 5, first, attach the transmission line 2 and the shield line 3 to the chip substrate 1, then measure the length of the transmission line 2, and set it as the length of the permalloy film 4 and the aluminum film 5, then measure the perimeter of the part of the transmission line 2 that does not contact the chip substrate 1, and set it as the width of the permalloy film 4, cut and cover the permalloy film 4, then measure the perimeter of the part of the permalloy film 4 that does not contact the chip substrate 1, and set it as the width of the aluminum film 5, cut and cover the aluminum film 5, and thus the separation method is completed. In this case, on the outer wall of the transmission line 2, only the part that does not contact the chip substrate 1 is covered with the permalloy film 4 and the aluminum film 5 in this order. Here, the transmission line 2 is attached to the chip substrate 1 by a method such as adhesion or welding.

[0057] Compared with the prior art, the method for isolating transmission lines 2 for RF power amplifiers of the present invention increases the distance between two adjacent transmission lines 2, provides shield lines 3 on both opposing sides of the transmission lines 2, then covers the outer wall of the transmission lines 2 with a permalloy film 4, further covers the outer wall of the permalloy film 4 with an aluminum film 5, and provides a plurality of inverted triangular grooves 51 at intervals on the outer wall of the aluminum film 5. In this way, the increase in the distance between the two adjacent transmission lines 2 and the configuration of the shield lines 3 enhance the degree of isolation between the two transmission lines 2, and reduce the effect of the parasitic capacitance between the transmission lines 2 on the RF signal transmitted by the transmission lines 2. By covering the transmission lines with the permalloy film 4, it is possible to avoid the interference of the induced magnetic field existing between the two adjacent transmission lines 2 with the RF signal transmitted inside the transmission lines 2, and further enhance the degree of isolation between the two transmission lines 2. By covering with the aluminum film 5 and providing the grooves 51, it is possible to prevent external electromagnetic waves from interfering with the RF signal transmitted inside the transmission line 2, and to enhance the degree of isolation between the transmission line 2 and the outside.

[0058] The present invention further provides another embodiment, which is a transmission structure of an RF power amplifier, as shown in FIG. 4 or FIG. 5, including a chip substrate 1 and at least two transmission lines 2 provided on the chip substrate 1, the distance between two adjacent transmission lines 2 is greater than 2.5 times the width of the transmission lines 2, shielding lines 3 are provided on the corresponding inner and outer sides of the transmission lines 2, a permalloy film 4 is coated on the outer wall of the transmission line 2, an aluminum film 5 is coated on the outer wall of the permalloy film 4, and a plurality of grooves 51 recessed inward and having an inverted triangular structure are provided at intervals on the outer wall of the aluminum film 5.

[0059] Preferably, the distance between two adjacent transmission lines 2 is greater than three times the width of the transmission lines 2 .

[0060] The shield wire 3, the permalloy coating 4, the aluminum coating 5 and the groove 51 in the aluminum coating 5 in this embodiment are all provided by the above-mentioned method for separating the transmission line for an RF power amplifier 2. Therefore, the transmission structure of the RF power amplifier in this embodiment can also achieve the technical effects achieved by the method for separating the transmission line for an RF power amplifier 2 in the above-mentioned embodiment.

[0061] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent transformation of the flow made by using the specification and drawings of the present invention, or direct or indirect application to other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A method for isolating a transmission line for an RF power amplifier, comprising the steps of: setting a distance between two adjacent transmission lines on a substrate to be greater than 2.5 times the width of the transmission lines, and providing shield lines on the corresponding inner sides of the transmission lines and on both outer sides of the transmission lines; coating an outer wall of the transmission line with a permalloy coating; and covering an outer wall of the permalloy film with an aluminum film, and providing a plurality of spaced grooves in the outer wall of the aluminum film, the grooves being recessed inward and having an inverted triangular structure.

2. 2. The method for isolating a transmission line for an RF power amplifier according to claim 1, wherein the depths of the plurality of grooves are equal and each is smaller than the thickness of the aluminum film, and the plurality of grooves are provided at equal intervals on the outer wall of the aluminum film.

3. Specifically, the step of coating the outer wall of the transmission line with a permalloy film includes the following steps: measuring the length of the transmission line and determining that as the length of the permalloy film; measuring the circumference of the transmission line and determining the width of the permalloy film; cutting a portion of the permalloy film corresponding to the transmission line from a permalloy material based on a length and a width of the permalloy film; 2. The method for separating a transmission line for an RF power amplifier according to claim 1, further comprising the sub-step of uniformly applying an insulating adhesive to one side of the permalloy film, and covering and fixing the side of the permalloy film to which the insulating adhesive is applied to an outer wall of the transmission line.

4. 4. The method for separating a transmission line for an RF power amplifier according to claim 3, wherein the material of the insulating adhesive is 2025DSI, and the thickness of the permalloy film is 40 μm to 50 μm.

5. After the step of covering and fixing the side of the permalloy coating on which the insulating adhesive is applied to the outer wall of the transmission line, 4. The method for separating a transmission line for an RF power amplifier according to claim 3, further comprising the step of heating the transmission line covered and fixed with the permalloy film in a high-temperature oven up to 150° C. and then removing the same.

6. Specifically, the step of coating the outer wall of the permalloy film with an aluminum film includes: measuring the length of the transmission line and setting it as the length of the aluminum coating; a sub-step of measuring the circumference of the permalloy film and determining the circumference as the width of the aluminum film; a sub-step of cutting the aluminum film corresponding to the permalloy film from an aluminum material based on a length and a width of the aluminum film; 2. The method for isolating a transmission line for an RF power amplifier according to claim 1, further comprising the sub-step of uniformly applying an insulating adhesive to one side of the aluminum film, and covering the side of the aluminum film to which the insulating adhesive is applied on an outer wall of the permalloy film.

7. 7. The method for separating a transmission line for an RF power amplifier according to claim 6, wherein the material of the insulating adhesive is 2025 DSI, and the thickness of the aluminum film is 35 μm to 45 μm.

8. After the step of coating the side of the aluminum film coated with the insulating adhesive onto the outer wall of the permalloy film, 7. The method of claim 6, further comprising the step of heating the transmission line, which is coated with the aluminum film and fixed, in a high-temperature oven up to 150° C. and then removing the transmission line.

9. 8. The method for isolating transmission lines for an RF power amplifier according to claim 7, wherein the depth of the groove is 20 μm to 25 μm, and the distance between two adjacent grooves is 0.5 mm to 0.8 mm.

10. 2. The method for separating a transmission line for an RF power amplifier according to claim 1, wherein the shielding wire is made of an insulating material, the width of the shielding wire is 50 μm to 55 μm, and the length of the shielding wire is equal to or longer than the length of the transmission line.

11. A transmission structure of an RF power amplifier, comprising: a substrate and at least two transmission lines provided on the substrate; a transmission structure for an RF power amplifier, characterized in that a distance between two adjacent transmission lines is greater than 2.5 times the width of the transmission lines, shielding wires are provided on the corresponding insides of the transmission lines and on both outsides of the transmission lines, an outer wall of the transmission lines is coated with a permalloy coating, an outer wall of the permalloy coating is coated with an aluminum coating, and a plurality of grooves recessed inwardly and having an inverted triangular structure are provided at intervals on the outer wall of the aluminum coating.

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