TWI478434B - Three - dimensional filter and its making method - Google Patents

Description

Three-dimensional filter and manufacturing method thereof

The present invention relates to filters, and more particularly to a stereoscopic filter and a method of fabricating the same.

In order to improve the quality of wireless communication, the received high-frequency signal is usually processed by a bandpass filter, which not only filters out unnecessary interference signals, but also enables high-frequency signals to have good reception quality. The high-efficiency band-pass filter is the main factor determining the communication quality, that is, the filter with high selectivity and low insertion loss; among them, high selectivity means the sideband ( The side band) has a very good suppression ability, which can reduce the guard band between adjacent channels, making the frequency use more efficient, and the key to the quality factor (Q) of the filter, and the insertion loss. It means the degree of attenuation of the signal through the filtering process, the loss of the conductor caused by the surface impedance of the conductor itself, the dielectric loss caused by the dielectric material around the conductor, and the radiation loss of the signal electromagnetic wave in space. The attenuation is low, and the insertion loss is low. The device can obtain a better high frequency receive gain for the signal.

For high-Q mechanical filters (such as comb filters), multi-level stereo resonators are made of metal with a specific thickness, so that the low surface impedance of the metal itself and the surrounding air medium can be utilized. The low dielectric loss quality factor (Quality factor), the signal filtering process to obtain good side wave suppression and low insertion loss; but the all-metal filter requires a lot of metal material to match the complex mold. The multi-stage resonator is formed, so that in addition to the high cost, the thickness is too thick and the volume is quite large, and the application of the integrated circuit module has no need to occupy a considerable circuit. space.

In order to reduce the manufacturing cost and reduce the volume, a microstrip filter made of copper foil on a printed circuit board, such as an inter-digital filter, An edge coupled micro-strip filter and a hairpin filter, but the thickness of the metal resonator of the filter made of the planar metal is too thin. The signal transmission process is caused by the high surface resistance of the conductor, and the signal transmission is affected by the dielectric loss of the printed circuit board, which makes it difficult for the filter itself to obtain a high Q value, which may cause the filter to have poor side-wave suppression capability. And the insertion loss is improved.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide a three-dimensional filter having an appropriate thickness and low manufacturing cost, and capable of increasing its own Q value.

A second object of the present invention is to provide a stereoscopic filter that can reduce dielectric loss.

In order to achieve the above object, the three-dimensional filter of the present invention comprises an insulating plate and two metal layers respectively disposed on the top and bottom surfaces of the insulating plate and electrically connected to each other through a plurality of through holes of the insulating plate. Conductively conducting, and forming a plurality of resonators on the two sides of the insulating plate and a frame surrounding the resonators, and adjacent two of the resonators and each of the resonators and the frame Forming a first resonant cavity and a second resonant cavity respectively, and the frame has two openings on at least one side of the insulating plate, and the outermost two of the resonant bodies respectively extend from the two openings to an input end And an output end for signal input and output.

Thereby, the three-dimensional filter of the present invention is relatively easy to manufacture and can increase its own Q value without requiring too much thickness, thereby obtaining higher side wave suppression capability and lower insertion loss; further, in order to reduce the insulation The dielectric loss between the adjacent two resonators may be hollow, and the resonant cavity between the resonator and the frame may also be hollow.

In a three-dimensional filter according to an embodiment of the present invention, the resonators are arranged in an array and have two adjacent first resonators and two adjacent second resonators, one of the first resonators. Forming two second resonant cavities between the second resonating body and the bezel; and the input end portion and the output end portion are formed by another of the first resonating body and the other second The resonators extend toward the two openings, respectively.

Preferably, the first resonant cavity between the two first resonant bodies and the two second resonant bodies is hollowed out, and one of the second resonant cavity between the resonant body and the frame has a partial insulating plate .

In another preferred embodiment, the first resonant cavity formed between the two first resonant bodies and the two second resonant bodies has a portion of the insulating plate, and the second resonance between the resonant body and the frame The cavity is hollow.

In another preferred embodiment, the input end portion and the output end portion are respectively extended from the two openings in opposite directions toward the two openings.

In a three-dimensional filter according to an embodiment of the present invention, the resonators are arranged in parallel with each other and perpendicular to opposite sides of the frame, and the resonant system and one side of the frame are electrically connected. Connecting and forming a second resonant cavity respectively by a predetermined distance from the other side of the bezel.

Preferably, the two openings are simultaneously provided on one side of the frame.

In another preferred embodiment, the two opposite sides of the frame are parallel to the resonators and are respectively provided with the two openings.

In another preferred embodiment, the input end portion and the output end portion are respectively extended from the two openings in opposite directions toward the two openings.

In another preferred embodiment, each of the first resonant cavities has a hollow shape, and the second resonant cavity formed between the end of each of the resonant bodies and the opposite sides of the bezel has a portion of the insulating plate. More preferably, the other two opposite sides of the frame are parallel to the resonators and form a hollow second cavity between the two outermost resonators.

In a three-dimensional filter according to an embodiment of the present invention, the input end portion and the output end portion are located on the same side of the frame, and the other side of the frame extends continuously along the periphery of the insulating plate.

In a three-dimensional filter according to an embodiment of the present invention, the insulating plate is made of glass fiber or ceramic material, and each of the metal layers and the through holes are made of the same conductive material.

Preferably, the insulating plate is made of a multi-layer fiberglass board, and each of the metal layers and the through holes are made of a material of copper or copper alloy.

It is still another object of the present invention to provide a method of manufacturing the aforementioned three-dimensional filter which can save manufacturing costs.

In order to achieve the above object, the manufacturing method of the three-dimensional filter of the present invention first provides an insulating plate, and then a metal layer is respectively disposed on the top and bottom surfaces of an insulating plate, and then a part of the metal layer is removed to form each metal layer. a plurality of resonant patterns and a border pattern surrounding the resonant patterns, and the resonant patterns of the two metal layers are the same, and any one or two of the border patterns have two openings, and the two resonant patterns adjacent to the two openings respectively Extending an input end portion and an output end portion toward the two openings, and then forming a plurality of perforations through the insulating plate for each of the resonant pattern and the frame pattern by mechanical processing, and finally forming a conductive layer on the holes of the perforated holes The plurality of through holes are formed such that the resonant patterns and their corresponding through holes form a resonant body, and each of the frame patterns and their corresponding through holes form a frame surrounding one of the resonators.

Thereby, the present invention produces the three-dimensional filter by a method of manufacturing a printed circuit board, which can effectively reduce the manufacturing cost.

In a method for fabricating a three-dimensional filter according to an embodiment of the present invention, wherein in step c), the resonant patterns are arranged in an array and have two adjacent first resonant bodies and two adjacent seconds. The resonant body, the input end portion and the output end portion are respectively extended from the two adjacent first resonant body and the second resonant body toward the two openings.

Preferably, in step d) or after step e), a portion of the insulating plate is removed, such that the two first resonant bodies and the two second resonant bodies are hollowed out, and each of the first resonant bodies A partial insulating plate is retained between the frame and each of the second resonator body and the frame.

Another preferred embodiment, wherein in step d) or after step e), part of the insulating plate is removed, so that a partial insulating plate is left between the two first resonant bodies and the two second resonant bodies, and each A side of one side of the first resonator and the frame and a side of each of the second resonators are hollowed out between the frame.

In a method for fabricating a three-dimensional filter according to an embodiment of the present invention, wherein in step c), the resonant patterns are parallel to each other, in step d) or after step e), and then mechanically processed. Part of the insulating plate is removed, so that adjacent two of the resonators are hollowed out.

Preferably, the portion of the insulating plate removed in step d) or after step e) is such that the outermost two of the resonators have a hollow shape between one side and the frame.

In the method for fabricating a three-dimensional filter according to an embodiment of the present invention, in the step c), the resonant patterns are parallel to each other, and the extending directions of the input end and the output end are parallel or perpendicular at the same time. Equal resonance pattern.

In the method for fabricating a three-dimensional filter according to an embodiment of the present invention, in the step c), the two openings are located on the same frame pattern, and the other frame pattern continuously extends along the periphery of the insulating plate. .

For a detailed description of the structure, features, and advantages of the present invention, several preferred embodiments are illustrated and described in conjunction with the following drawings.

Referring to the first embodiment, a three-dimensional filter 10 according to a first embodiment of the present invention includes an insulating plate 20 and two metal layers 30. The insulating plate 20 may be made of single or multiple layers of fiberglass or The ceramic material, in which the multi-layer fiberglass board is the best embodiment, each metal layer 30 is made of a conductive material and the material of copper or copper alloy is the best embodiment.

The two metal layers 30 are respectively disposed on the top and bottom surfaces of the insulating plate 20, and each of the metal layers 30 has a complex resonant pattern 38 and a border pattern 39 surrounding the resonant pattern 38, and the corresponding two metal layers 30 The resonant pattern 38 is electrically connected to each other through a plurality of through holes 31 extending through the insulating plate 20, and forms a resonant body 32 with the through holes 31. The frame patterns 39 of the two metal layers 30 are mutually connected via the plurality of through holes 31. Electrically conductive, and forming a frame 33 with the through holes 31. In this embodiment, the resonators 32 are arranged parallel to each other and perpendicular to the two long sides of the frame 33 and the two short sides of the parallel frame 33, so that a first space is formed between the adjacent two resonators 32. The resonant cavity 34 is electrically connected to one of the long sides of the frame 33 and spaced apart from the other long side of the frame 33 by a predetermined distance to form a second resonant cavity 35; The frame pattern 39 of the bottom surface of the board 20 continuously extends along the periphery of the insulating board 20. As shown in the second figure, one of the long sides of the border pattern 39 on the top surface of the insulating board 20 has two openings 332 at the same time. The outer two resonators 32 respectively extend from the two openings 332 to an input end portion 36 and an output end portion 37 for inputting and outputting signals.

Thereby, after the high frequency signal is input from the input end portion 36, the second resonant cavity 35 formed by the frame 33 can be matched via the coupling resonance between the resonators 32 to obtain the optimum signal gain and side. The wave suppresses the bandwidth to filter out unnecessary signals and finally outputs it from the output terminal 37. Since the three-dimensional filter 10 provided by the present invention utilizes the arrangement of the resonant patterns 38 on both sides of the single insulating plate 20 and the through holes 31, it can have a high Q value equivalent to that provided by a conventional mechanical filter. The resonator body 32 is relatively easy to manufacture and can increase its own Q value without requiring too much thickness, thereby achieving high side wave suppression capability and low insertion loss, and high-frequency signals with good communication quality.

It should be noted that the design of the two openings 332 mainly considers the structure of the front and rear stages of the filter 10, and is not necessarily disposed on the same side of the same side of the frame 33, and may also be disposed on the frame. The different sides of the same side of the 33, the input end and the output end are respectively extended from the outermost two of the resonators in opposite directions, for example, the two openings 332 are respectively disposed on the two long sides or On the two short sides, or if the front and rear circuits of the filter 10 are respectively connected to the circuit layer structures of different plane heights, the two openings may be respectively disposed on different sides of the frame 33.

The above is the structure of the first preferred embodiment of the present invention, and the manufacturing method of the present invention will be described below in conjunction with the first and seventh figures.

a): An insulating plate 20 made of a glass fiber material is provided.

b): A layer of copper or a copper alloy is provided as the metal layer 30 on both the top and bottom surfaces of the insulating plate 20.

c): removing a portion of the metal layer 30 such that each of the metal layers 30 forms a plurality of resonant patterns 38 and a border pattern 39 surrounding the resonant patterns 38, and the resonant patterns 38 of the two metal layers 30 are the same, one of which The bezel pattern 39 has the two openings 332, the input end 36, and the output end 37.

d): a plurality of perforations penetrating through the insulating plate 20 are formed on each of the resonant patterns 38 and the frame patterns 39 by mechanical processing.

e) forming a plurality of conductive vias 31 on the walls of the perforations, such that the resonant patterns 38 and their corresponding through holes 31 form a resonator body 32, and each of the frame patterns 39 and their corresponding through holes 31 The frame 33 is formed, thus completing the fabrication of the stereoscopic filter 10 of the present invention.

In order to reduce the dielectric loss generated by the insulating plate 20 and increase the overall Q value, a portion of the insulating plate 20 may be mechanically removed after the step d) or the step e) to allow the adjacent two resonators 32 to be separated. The first resonant cavity 34 is formed in a hollow shape, and a partial insulating plate 20 is left between the end of each resonant body 32 and the frame 33 to maintain the second resonant cavity 35 in a non-hollow shape, as shown in the third and fourth figures. In addition, a second cavity 35 having a hollow shape is formed between the short side of the frame 31 and the outermost two resonators 32, respectively.

Referring to FIG. 5 again, a three-dimensional filter 40 according to a second preferred embodiment of the present invention also includes an insulating plate 50 and a two-metal layer 60. The difference from the above embodiment lies in the three-dimensional filter. 40 is a multi-stage coupled resonance form having electrical coupling, magnetic coupling, and electromagnetic coupling. Taking a multi-stage serial C-shaped transmission line structure as an example, that is, a four-string multi-stage coupling filter as exemplified in the embodiment, The four resonators formed by the two metal layers 60 are arranged in an array, and are divided into two first resonators 61a, 61a' and two second resonators 61b, 61b', between the first resonators 61a and 61a'. A first resonant cavity 63, a first resonant body 61a and a second resonant cavity 63 are formed between each of the second resonant bodies 61b and 61b' and between the adjacent first resonant body 61a or 61a' and the second resonant body 61b or 61b'. A second resonant cavity 64 is formed between the second resonant body 61b and the frame 62, and the second resonant cavity 64 is formed between the first resonant body 61a' and the second resonant body 61b' and the frame 62. In the electric loss consideration, the two first resonating bodies 61a, 61a' and the second second harmonic are made Each of the first resonant cavities 63 between the bodies 61b and 61b' is hollowed out, and the first resonant body 61a' and the bezel 62 are formed between the second resonating body 61b' and the bezel 62. A second resonant cavity 64 is hollowed out as shown in the fifth figure. Further, the input end portion 65 and the output end portion 66 are extended from the adjacent first and second resonators 61a and 61b in opposite directions toward the two openings 67. Therefore, when the signal is input from the input end portion 65, the resonant bodies 61a to 61b are excited by multi-level electrical and magnetic coupling to achieve the purpose of filtering the signal.

On the other hand, the manufacturing method of the embodiment is substantially the same as that of the above embodiment, and details are not described herein again. The difference between the two is only that after step d) or step e), part of the insulating plate 50 can be removed by machining to be vertical. The insulating plate 50 extending in the extending direction of the two openings 67 serves to fix the resonators 61a to 61b so that the first resonant cavities 63 perpendicular to the extending direction of the two openings 67 are hollowed out and adjacent to the two openings 67. The second resonant cavity 64 is hollowed out. It should be additionally noted that the hollowed-out configuration of each of the first resonant cavity 63 and each of the second resonant cavities may be changed, and the insulating plate 50 parallel to the extending direction of the two openings 67 may be modified as the fixed resonant body. 61a to 61b, for example, each of the first resonant cavities 63 formed between the first resonant bodies 61a and 61a' and between the second resonant bodies 61b and 61b' is hollow and extends parallel to the two openings 67. Each of the second resonant cavities 64 in the direction is also hollow, as shown in the sixth figure.

In summary, the three-dimensional filter of the present invention is made of an insulating board and two metal layers by a printed circuit technology, which is not only easy to process but also has an appropriate thickness after the manufacturing is completed, so as to reduce manufacturing cost and increase Q value. For the purpose, the unnecessary portion of the insulating plate can be removed according to actual needs to reduce the dielectric loss, so that the three-dimensional filter of the present invention can obtain higher side wave suppression capability and lower insertion loss.

The constituent elements of the present invention disclosed in the foregoing embodiments are merely illustrative and are not intended to limit the scope of the present invention. The alternative or variations of other equivalent elements are also covered by the scope of the patent application.

"First Embodiment"

10. . . Stereoscopic filter

20. . . Insulation board

30. . . Metal layer

31. . . Through hole

32. . . Resonant body

33. . . frame

332. . . Opening

34. . . First cavity

35. . . Second cavity

36. . . Input end

37. . . Output end

38. . . Resonant pattern

39. . . Border pattern

"Second embodiment"

40. . . Stereoscopic filter

50. . . Insulation board

60. . . Metal layer

61a, 61a’. . . First resonator

61b, 61b’. . . Second resonator

62. . . frame

63. . . First cavity

64. . . Second cavity

65. . . Input end

66. . . Output end

67. . . Opening

The first figure is a plan top view of a first preferred embodiment of the present invention;

The second figure is a plan bottom view of the above first preferred embodiment;

The third figure is another plan top view of the first preferred embodiment of the present invention, mainly showing the state after removing a part of the insulating board;

The fourth figure is a cross-sectional view of the third figure taken along line 4-4;

Figure 5 is a plan top view of the second preferred embodiment and showing the state after removal of a portion of the insulating sheet;

Figure 6 is another plan top view of the second preferred embodiment of the present invention, and shows a top view of the state after removing a portion of the insulating sheet;

The seventh figure is a flow chart of the manufacturing method of the present invention.

10. . . Stereoscopic filter

20. . . Insulation board

30. . . Metal layer

31. . . Through hole

32. . . Resonant body

33. . . frame

332. . . Opening

34. . . First cavity

35. . . Second cavity

36. . . Input end

37. . . Output end

38. . . Resonant pattern

39. . . Border pattern

Claims (21)

A three-dimensional filter includes: an insulating plate; and two metal layers respectively disposed on the top and bottom surfaces of the insulating plate and electrically electrically connected to each other through a plurality of through holes penetrating the insulating plate, the two metal layers And the through holes respectively form a plurality of resonators having the same pattern on the two sides of the insulating plate and a frame surrounding the resonators, and a first cavity is formed between the two adjacent resonators and each of the holes Forming a second resonant cavity between the at least one side of the resonant body and the frame, the frame has two openings on at least one side of the insulating plate, and the two outermost resonators respectively extend an input toward the two openings End and an output end. The stereoscopic filter of claim 1, wherein the resonators are arranged in an array and have two adjacent first resonators and two adjacent second resonators, wherein the first resonator and the resonator Forming two second resonant cavities between the frame and one of the second resonant body and the bezel; the input end portion and the output end portion are formed by another of the first resonant body and the other of the second resonant body Extending toward the two openings respectively. The three-dimensional filter according to claim 2, wherein the first resonant cavity between the two first resonant bodies and the two second resonant bodies is hollowed out, and one of the two between the resonant body and the frame is the second The cavity has a portion of the insulating plate. The three-dimensional filter according to claim 2, wherein the first resonant cavity formed between the two first resonant bodies and the two second resonant bodies has a portion of the insulating plate, and between the resonant body and the frame One of the second resonant cavities is hollowed out. The stereoscopic filter of claim 1, wherein the resonant bodies are arranged in parallel with each other and perpendicular to opposite sides of the frame, and each of the resonant systems is electrically connected to one side of the frame, and A second resonant cavity is formed by a predetermined distance from the other side of the bezel. The three-dimensional filter of claim 5, wherein the two sides of the frame are simultaneously provided with the two openings. The three-dimensional filter of claim 5, wherein two opposite sides of the frame are parallel to the resonators and are respectively provided with the two openings. The three-dimensional filter according to claim 2 or 5, wherein the input end portion and the output end portion are respectively extended from the two openings in opposite directions toward the two openings. The three-dimensional filter according to claim 5, wherein each of the first resonant cavities has a hollow shape, and the second resonant cavity formed between the end of each of the resonant bodies and the opposite sides of the bezel has a local portion. Insulation board. The stereoscopic filter of claim 9, wherein the other opposite sides of the frame are parallel to the resonators and form a hollow second cavity between the two outermost resonators. The stereoscopic filter of claim 1, wherein the input end and the output end are located on the same side of the frame, and the other side of the frame extends continuously along the periphery of the insulating plate. The three-dimensional filter according to claim 1, wherein the insulating plate is made of glass fiber or ceramic material, and each of the metal layers and the through holes are made of the same conductive material. The three-dimensional filter according to claim 12, wherein the insulating plate is made of a multi-layer fiberglass board, and each of the metal layers and the through holes are made of a material of copper or copper alloy. A method for fabricating a three-dimensional filter includes the steps of: a) providing an insulating plate; b) providing a metal layer on each of the top and bottom surfaces of the insulating plate; c) removing a portion of the metal layer for each of the metals The layer forms a plurality of resonant patterns and a border pattern surrounding the resonant patterns, and the resonant patterns of the two metal layers are the same, and any one or two of the border patterns have two openings, and the two adjacent to the two openings have the resonance Forming an input end and an output end respectively toward the two openings; d) forming a plurality of perforations through the insulating plate for each of the resonant pattern and the frame pattern by machining; and e) holes for the perforations A plurality of through holes are formed on the wall, so that the resonant patterns and the corresponding through holes form a resonant body, and each of the frame patterns and the corresponding through holes form a frame. The method of claim 14, wherein in step c), the resonant patterns are arranged in an array and have two adjacent first resonant bodies and two adjacent second resonant bodies, the input end and The output end portion is extended from the two adjacent first and second resonators toward the two openings. The manufacturing method of claim 15, wherein in step d) or after step e), a portion of the insulating plate is removed, such that the two first resonant bodies and the two second resonant bodies are hollowed out, and A partial insulating plate is retained between each of the first resonant body and the frame and between the second resonant body and the frame. The manufacturing method of claim 15, wherein in step d) or after step e), part of the insulating plate is removed, so that partial insulation is left between the two first resonant bodies and the two second resonant bodies. The board has a hollow shape between one side of each of the first resonators and the frame and between one side of each of the second resonators and the frame. The manufacturing method of claim 14, wherein in step c), the resonant patterns are juxtaposed in parallel with each other, and in step d) or after step e), a portion of the insulating sheets are removed by machining to make adjacent Second, the resonators are hollowed out. The manufacturing method of claim 18, wherein the portion of the insulating plate removed in step d) or after step e) further causes the outermost two of the resonators to have a hollow side between the side and the frame, respectively. . The manufacturing method of claim 14, wherein in step c), the resonant patterns are juxtaposed in parallel with each other, and the extending directions of the input end and the output end are parallel or perpendicular to the resonant patterns. The manufacturing method of claim 14, wherein in the step c), the two openings are located on the same frame pattern, and the other frame pattern continuously extends along the periphery of the insulating plate.