Antenna radio frequency filter assembly

Abstract

This invention relates to an antenna radio frequency filter assembly. Specifically, the antenna radio frequency filter assembly of this invention includes: a plurality of bandpass filters (BPF); a filter board, stacked on the front of a motherboard, serving as a medium for combining the front of the motherboard with the bandpass filters; a low-pass filter (LPF), embossed or relief-printed on the front of the filter board; and an air layer forming sheet disposed between the filter board and the bandpass filters, for forming a predetermined air layer between the front of the filter board and the back of the bandpass filters. This provides the advantage that the overall performance of the filter product can be improved by minimizing the insertion loss of the filters.

Description

Technical Field

[0001] This invention relates to a radio frequency filter assembly for antennas, and more specifically, to a radio frequency (RF) filter assembly for antennas that reduces insertion loss and is easy to set up and assemble. Background Technology

[0002] To meet the increasing demand for wireless data communication following the commercialization of 4G (fourth generation) communication systems, research and development of improved 5G (fifth generation) or pre-5G communication systems are underway. For this reason, 5G or pre-5G communication systems are referred to as Beyond 4G Network communication systems or Post-LTE systems, representing the future of Long Term Evolution (LTE).

[0003] To achieve high data transmission rates, 5G communication systems consider using ultra-high frequency (mmWave) bands (e.g., 60 GHz band). To reduce path loss and increase propagation distance of radio waves in the mmWave band, technologies such as beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antennas are being researched in 5G communication systems.

[0004] In particular, array antenna technology involves the integration of multiple filters and antenna components—one of the antenna elements—on the front of a single-board motherboard. Furthermore, achieving resistance matching between multiple receive and transmit channels requires high physical precision. Recently, in the 5G communication system market, there has been a growing demand for ceramic waveguide filters (CWB filters) among various array antennas, facilitating both frequency filtering design and manufacturing. This necessitates a mass production technology to meet the demand for CWB filters.

[0005] Figure 1 This is a schematic diagram illustrating the stacked state of prior art antenna radio frequency filter assemblies.

[0006] like Figure 1As shown, in an example 1 of a prior art antenna RF filter assembly, on the front of the main board 10, multiple ceramic waveguide filters 20 (CWF), which are a type of band pass filter (BPF), are mounted on a fixed printed circuit board 5 (PCB) as a medium. Inside the fixed printed circuit board 5, a microstrip filter 30, which is a type of low pass filter (LPF), is integrally stacked.

[0007] However, Example 1 of the prior art antenna RF filter assembly constructed as described above has the following problem: since the microstrip filter 30 is located inside the fixed printed circuit board 5 formed of dielectric material (or ceramic material), excessive low-pass filter insertion loss will occur.

[0008] That is, with the microstrip filter 30 as the center, the dielectric material covers both sides, which correspond to the motherboard 10 side and the ceramic waveguide filter 20 side, which will eventually result in a large insertion loss of the microstrip filter 30. Summary of the Invention

[0009] Technical issues

[0010] The present invention addresses the technical problems described above and aims to provide an antenna radio frequency filter assembly that minimizes insertion loss.

[0011] Furthermore, another objective of the present invention is to provide an antenna radio frequency filter assembly that improves assemblability and productivity.

[0012] The purpose of this invention is not limited to the purposes mentioned above. Other purposes not mentioned can be clearly understood by those skilled in the art through the following description.

[0013] Technical solution

[0014] An antenna radio frequency filter assembly according to an embodiment of the present invention includes: a plurality of bandpass filters; a filter board, stacked on the front of a motherboard, serving as a medium for combining the front of the motherboard with the bandpass filters; a low-pass filter, on the front of the filter board, wherein capacitor lines acting as capacitors and inductor lines acting as inductors are printed in an intaglio or relief manner; and an air layer forming sheet, disposed between the filter board and the bandpass filters, for forming a predetermined air layer between the front of the filter board and the back of the bandpass filters.

[0015] The aforementioned bandpass filter may include a ceramic waveguide filter made of ceramic material.

[0016] Furthermore, the aforementioned filter board may contain either a dielectric material or an FR4 material.

[0017] Furthermore, the aforementioned air layer forming sheet can be made of metal or dielectric material.

[0018] Furthermore, the aforementioned low-pass filter may include a microstrip line filter, which is made of a conductive material and is integrally exposed on the front of the aforementioned filter board.

[0019] Furthermore, from the input position of the power supply signal to the output position, the microstrip line filter can be printed and formed on the front of the filter board according to a specified pattern shape. A low-pass filter circuit receiving part can be formed by cutting the air layer sheet to receive the specified pattern shape of the microstrip line filter.

[0020] Furthermore, an input port and an output port for inputting and outputting power supply signals can be respectively separated and connected on the back side of the aforementioned bandpass filter. A bandpass filter port receiving portion can be formed by cutting the aforementioned air layer forming sheet to receive the positions corresponding to the input port and output port of the aforementioned bandpass filter respectively.

[0021] Furthermore, the aforementioned air layer forming sheet may include: a partition body for separating the bandpass filter from the front of the filter board by a predetermined distance; and an input port support and an output port support, which are disposed inside the partition body and separated from the partition body, such that the portions corresponding to the input ports and output ports for inputting and outputting power signals to the bandpass filter are separated from the filter board.

[0022] Furthermore, the aforementioned partition body, the aforementioned input port support, and the aforementioned output port support can each separate the aforementioned plurality of bandpass filters at the same height.

[0023] Furthermore, the aforementioned partition body may include: a support plate portion, which is attached to the back of the bandpass filter in a surface-to-surface manner; and an edge support end, which is bent toward the front of the filter plate at the edge end of the support plate portion.

[0024] Furthermore, the aforementioned edge support end can be formed into a shape with concave and convex portions repeatedly formed along the edge end.

[0025] Furthermore, in the aforementioned microstrip line filter, the capacitor line on one side that acts as a capacitor, the capacitor line on the other side that is arranged side by side and separated from the capacitor line on the one side, and the inductor line that connects the capacitor line on the one side and the capacitor line on the other side can be repeatedly formed within a specified range, and part or all of the inductor line can be separated from the front of the filter board.

[0026] Furthermore, the filter board may be formed with a hole or slot-shaped separation cut for separating all or part of the inductor lines.

[0027] The effects of the invention

[0028] According to an embodiment of the present invention, the antenna radio frequency filter assembly can minimize the insertion loss of the microstrip line filter, thereby improving the performance of the filter.

[0029] Furthermore, the antenna radio frequency filter assembly according to an embodiment of the present invention has the effect of improving assemblability and productivity. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the stacked state of prior art antenna radio frequency filter assemblies.

[0031] Figure 2a as well as Figure 2b This is a perspective view of an antenna radio frequency filter assembly according to an embodiment of the present invention.

[0032] Figure 3 for Figure 2a An exploded 3D diagram.

[0033] Figure 4 To show Figure 3 A 3D view of the radio frequency filter in the structure shown.

[0034] Figure 5 To show that Figure 2a The diagram shows a perspective view of the filter board with the microstrip line filter in the structure, where one side is combined with the air layer to form a sheet.

[0035] Figure 6 To show Figure 2a A three-dimensional view of the air layer forming a sheet in the structure shown.

[0036] Figure 7 To show Figure 2a The diagram shows a three-dimensional view of a filter board with a microstrip line filter.

[0037] Figure 8 To show Figure 2a The diagram shows a top view of a filter board in which a microstrip line filter is installed.

[0038] Figure 9 For along Figure 8 The sectional view taken by line AA in the figure belongs to the sectional view of the filter board showing different embodiments.

[0039] Figure 10 For along Figure 2a The sectional view taken by the BB line.

[0040] Figure 11 A scatter plot is provided to illustrate the radio frequency characteristics of the bandpass filter in the structure of an antenna radio frequency filter assembly according to an embodiment of the present invention.

[0041] Figure 12 A scatter plot is provided to illustrate the radio frequency characteristics of a low-pass filter in the structure of an antenna radio frequency filter assembly according to an embodiment of the present invention.

[0042] Figure 13 To illustrate the merger Figure 11 as well as Figure 12 The scatter plot of the RF characteristics of the results.

[0043] Explanation of reference numerals in the attached figures

[0044] 100: Antenna RF filter assembly; 105: Filter board

[0045] 110: Motherboard; 120: Ceramic waveguide filter

[0046] 121: Filter body 122: Resonator column

[0047] 123: Modulation cover 124: Cutting plate

[0048] 125: Filter cover; 130: Microstrip line filter

[0049] 131a: Input port location; 131b: Output port location

[0050] 133: Pattern shape part; 135a: Capacitor line on one side.

[0051] 135b: Capacitor wire on the other side; 135c: Inductor wire.

[0052] 137: Welding groove; 140: Air layer forming sheet

[0053] 141, 142: Separating part body 141: Support plate part

[0054] 142: Edge support end; 143: Input port support and output port support.

[0055] 145: Bandpass filter port housing 149: Low-pass filter loop housing

[0056] 150: Signal line cut-off section S: Imitation Detailed Implementation

[0057] Hereinafter, an embodiment of the antenna radio frequency filter assembly of the present invention will be described in detail with reference to the accompanying drawings.

[0058] In assigning reference numerals to structural elements in the various figures, the same reference numerals are assigned to the same structural elements as much as possible, even if they appear in different figures. Furthermore, in describing embodiments of the present invention, if it is determined that a detailed description of a related well-known structure or function may hinder the understanding of the embodiments of the present invention, its detailed description is omitted.

[0059] In describing the structural elements of the embodiments of the present invention, terms such as "first," "second," "A," "B," "(a)," and "(b)" may be used. These terms are only used to distinguish a structural element from other structural elements, and the nature, sequence, or order of the corresponding structural elements is not limited by their terminology. Furthermore, unless otherwise defined, the meanings of all terms used in the specification, including technical or scientific terms, are the same as those commonly understood by one of ordinary skill in the art to which this invention pertains. Multiple terms whose commonly used meanings are the same as those defined in dictionaries should be interpreted as having the same meaning as the related art in the context, and should not be interpreted in an idealized or overly formalized sense unless explicitly defined in this application.

[0060] Figure 2a as well as Figure 2b To illustrate a perspective view of an antenna radio frequency filter assembly according to an embodiment of the present invention, Figure 3 for Figure 2a Decomposed 3D diagram, Figure 4 To show Figure 3 A 3D view of the radio frequency filter in the structure shown.

[0061] As in 2a to Figure 4 As shown, an antenna radio frequency filter assembly 100 according to an embodiment of the present invention includes a main board 110, radio frequency filters 120 and 130, and an air layer forming sheet 140.

[0062] The motherboard 110 is a single-board printed circuit board (PCB). Multiple RF filters 120, 130 or a portion of multiple electrical components (not shown) synchronized with them can be mounted on one side, and multiple electrical components (not shown) consisting of multiple power supply related components can be mounted on the other side to perform calibration power supply control to the multiple RF filters 120, 130.

[0063] In one embodiment of the invention, for ease of explanation, the other side of the motherboard 110, which is composed of a single-board printed circuit board, is shown ( Figure 2aThe above figure in the figure shows the formation of a single air layer forming sheet 140, but this does not mean that the following configuration is excluded: the air layer forming sheet 140 is formed in an inherent shape at all or part of the configuration positions of the plurality of radio frequency filters 120, 130, and is stacked in multiple positions relative to the entire surface of the motherboard 110.

[0064] The radio frequency filters 120 and 130 may include multiple bandpass filters 120 and low-pass filters 130.

[0065] The bandpass filter 120 can be configured as a ceramic waveguide filter made of ceramic material, and the low-pass filter 130 can be configured as a microstrip line filter.

[0066] like Figure 3 As shown, a plurality of ceramic waveguide filters (hereinafter referred to as "120") composed of a type of bandpass filter may each include: a filter body 121, made of ceramic material; and four or more resonant blocks disposed on the filter body 121. Each resonant block is provided with a corresponding resonator post 122, and each resonator post 122 filters the frequency signal through adjacent coupling with adjacent resonator posts 122 or by skipping at least one cross-coupling.

[0067] The resonant blocks 11, 12, 13, 14, 15, and 16 formed on the filter body 121 do not need to be completely physically separated. It is sufficient that they can be distinguished by changing the signal transmission path width through the partition set on the filter body 121.

[0068] For example, such as Figure 4 As shown, six resonator pillars 122a, 122b, 122c, 122d, 122e, and 122f are provided in the filter body 121. If an electrical signal is input through an input port hole (not shown in the following description), the signal is applied through the first resonator pillar 122a closest to the input port hole, and filtering is performed sequentially through the second resonator pillar 122b, the third resonator pillar 122c, the fourth resonator pillar 122d, the fifth resonator pillar 122e, and the sixth resonator pillar 122f. The signal is then output through an output port hole (not shown).

[0069] Specifically, the first resonant block 11 and the second resonant block 12 are divided by setting a first partition 127a between the first resonator column 122a and the second resonator column 122b; the second resonant block 12 and the third resonant block 13 are divided by setting a second partition 127b between the second resonator column 122b and the third resonator column 122c; the third resonant block 13 and the fourth resonant block 14 are divided by setting a portion of the third partition 127c between the third resonator column 122c and the fourth resonator column 122d; the fourth resonant block 14 and the fifth resonant block 15 are divided by setting a fourth partition 127d between the fourth resonator column 122d and the fifth resonator column 122e; and the fifth resonant block 15 and the sixth resonant block 16 are divided by setting the remaining portion of the third partition 127c between the fifth resonator column 122e and the sixth resonator column 122f. In particular, the third partition 127c serves to physically divide the three resonant blocks (the first resonant block 11, the third resonant block 13, and the sixth resonant block 16) simultaneously by being positioned between the first resonator column 122a, the third resonator column 122c, and the sixth resonator column 122f.

[0070] The first partition 127a, the second partition 127b, the third partition 127c, and the fourth partition 127d described above can all be formed to a predetermined size that runs through the filter body 121 in the vertical direction.

[0071] The filter body 121 is coated with a metal film, which can block the flow of electrical signals from the inside and outside, except for the power supply signal input port and output port described later.

[0072] As described above, in order to perform filtering based on the adjacent coupling or cross coupling of electrical signals flowing through input ports or output ports (not shown), at least four resonant blocks are preferably provided on the filter body 121. In one embodiment of the present invention, six resonant blocks are provided as an example.

[0073] That is, in the antenna radio frequency filter assembly 100 of one embodiment of the present invention, the ceramic waveguide filter 120 is provided with six resonant blocks 11, 12, 13, 14, 15, and 16 in a filter body 121. The resonator pillars 122a, 122b, 122c, 122d, 122e, and 122f of each resonant block 11, 12, 13, 14, 15, and 16 can be arranged in a form filled and fixed by a dielectric material having a specified capacitance. Air is also a type of dielectric material. When air is used as the dielectric material constituting the resonator pillars 122a, 122b, 122c, 122d, 122e, and 122f, no separate filling and fixing steps are required. The six resonator pillars 122a, 122b, 122c, 122d, 122e, and 122f can be formed in a hollow form by removing a portion of the dielectric material from the filter body 121.

[0074] Among them, such as Figure 4 As shown, a portion of the inner surfaces of the resonator pillars 122a, 122b, 122c, 122d, 122e, and 122f, and a portion of one side of the filter body 121 corresponding to the upper edge portions of the resonator pillars 122a, 122b, 122c, 122d, 122e, and 122f, can be coated with conductive material to form a coating portion 126a, 126b, 126c, 126d, 126e, and 126f. A portion of the coating portion 126a, 126b, 126c, 126d, 126e, and 126f may further include a coating extension end 126f-1 extending closer to the corresponding resonator pillar 126d, so as to easily achieve cross-coupling between portions of the resonator pillars 122a, 122b, 122c, 122d, 122e, and 122f.

[0075] In one embodiment of the present invention, on one side of the filter body 121, a coating extension end 126f-1 can be formed extending from the coating portion 126f formed on the sixth resonator post 122f toward the coating portion 126d of the fourth resonator post 122d in a close manner, so as to form a cross-coupling between the fourth resonator post 122d and the sixth resonator post 122f that skips a fifth resonator post 122e, and cross-coupling can be easily achieved.

[0076] Moreover, referencing Figure 4An arc-shaped portion 128, without any coating layer, can be provided around each of the coated portions 126a, 126b, 126c, 126d, 126e, and 126f. The arc-shaped portion 128 can perform a grounding function to insulate the portion coated on the outer surface of the filter body 121 from the coated portions 126a, 126b, 126c, 126d, 126e, and 126f of the resonator pillars 122a, 122b, 122c, 122d, 122e, and 122f.

[0077] On the other hand, although not shown, an input port hole (not shown) and an output port hole (not shown) can be formed on the other side of the ceramic waveguide filter 120. The input port hole is used to connect to the input port of one of the six resonator pillars 122 for an input electrical signal, and the output port hole is used to connect to the output port of one of the six resonator pillars 122 for an output electrical signal. Input ports and output ports can be provided in the input port hole and output port hole, using the input port support portion and output port support portion 143 in the structure of the air layer forming sheet 140 (described later) as a medium to connect to the motherboard 110 side.

[0078] Moreover, such as Figure 3 As shown, the ceramic waveguide filter 120 may further include: a modulation cover 123 disposed on one side of the opening of each resonator post 122, configured to perform frequency modulation by means of a etch or modulation screw; and a filter cover 125, which is combined to cover one side of the filter body 121 including the modulation cover 123.

[0079] When the frequency modulation method is etched, the etched plate 124 can be integrally formed on the modulation cover 123. The etched plate 124 is spaced apart and positioned corresponding to the resonator post 122. The spacing between the resonator post 122 and the bottom surface can be finely adjusted by etching with an etching tool (not shown), thereby performing frequency modulation.

[0080] On the other hand, such as Figure 3 As shown, a microstrip line filter, which is a type of low-pass filter 130, can be formed in the form of being printed on the front of the filter board 105, or it can be inserted and injection molded with its front exposed to the side of the band-pass filter 120 stacked in front.

[0081] The filter board 105 may be made of either a dielectric material or FR4 material. When the filter board 105 is made of a dielectric material, the structural design of the filter board 105 may be modified to reduce the insertion loss of the microstrip line filter printed in front of it as a low-pass filter 130, as will be described later. Specific details related to this will be explained in detail later.

[0082] When using the bandpass filter 120 to completely end the filtering of a specific frequency band, there is no need to set up a separate low-pass filter 130. However, in one embodiment of the present invention, since the bandpass filter 120 is a ceramic waveguide filter 120, it may produce a distortion phenomenon on one side of both ends of the passband due to the characteristics of the ceramic material. Therefore, a low-pass filter 130 can be added to eliminate the distortion phenomenon.

[0083] Among them, with Figure 1 Compared to existing technologies, the low-pass filter 130 used as a microstrip line filter adopts a form in which the front part of the fixed printed circuit board made of dielectric material (or ceramic material) is removed, thereby minimizing the insertion loss caused by contact with the dielectric material (or ceramic material).

[0084] However, the ceramic waveguide filter 120, which is one of the bandpass filters 120 stacked in front of the microstrip line filter 130 as the low-pass filter 130, is also made of ceramic material. Therefore, in order to minimize the insertion loss of the microstrip line filter 130 as the low-pass filter 130 caused by the use of ceramic material in the bandpass filter 120, the antenna RF filter assembly 100 of an embodiment of the present invention may further include an air layer forming sheet 140.

[0085] like Figures 2a to 4 As shown, the air layer forming sheet 140 can be disposed between the filter plate 105 and the plurality of ceramic waveguide filters 120 to separate the ceramic waveguide filters 120 from the front of the filter plate 105.

[0086] The air layer forming sheet 140 described above can be made entirely of metal or dielectric material. The metal material may include one of steel, stainless steel (SUS), and pure copper (Cu).

[0087] Figure 5 To show that Figure 2a The diagram shows a perspective view of the filter board with the microstrip line filter integrated with the air layer in the structure shown. Figure 6 To show Figure 2a The diagram shows a three-dimensional view of the air layer forming a sheet in the structure shown. Figure 7 To show Figure 2a The diagram shows a three-dimensional view of a filter board with a microstrip line filter. Figure 8 To show Figure 2a The diagram shows a top view of a filter board in which a microstrip line filter is installed. Figure 9 For along Figure 8The sectional view taken by line AA in the figure.

[0088] Reference Figure 3 and Figure 5 The air layer forming sheet 140 may include: spacer bodies 141 and 142, the shapes of which correspond to the outer shape of the filter plate 105, for separating the bandpass filter 120 from the front of the filter plate 105 by a predetermined distance; and input port support and output port support 143, which are disposed inside the spacer bodies 141 and 142 and spaced apart from the spacer bodies 141 and 142 along the same surface direction, such that the portions corresponding to the input ports and output ports for inputting and outputting power signals to the plurality of ceramic waveguide filters 120 are separated from each filter plate 105. The input port support and output port support 143 are formed in a pair corresponding to the input port holes and output port holes respectively formed on the ceramic waveguide filters 120.

[0089] The partition bodies 141 and 142, and the input port support and output port support 143 can be spaced apart from the front of the filter plate 105 at the same height. This will be explained in more detail later.

[0090] like Figure 6 As shown, the separation body 141, 142 may include: a support plate 141, which is attached to the back of a plurality of ceramic waveguide filters serving as a bandpass filter 120 in a surface-contact manner; and an edge support end 142, which is bent toward the front of the filter plate 105 at the edge end of the support plate 141.

[0091] The edge support end 142 is formed along the outer edge end of the support plate portion 141, and can be bent toward the back side of the support plate portion 141 and extended toward the front of the filter plate 105 by a predetermined length.

[0092] As described above, the edge support end 142 is formed with a concave-convex shape, consisting of recesses 142a and protrusions 142b, repeatedly formed along the outer edge of the support plate portion 141. This is not only to minimize the welding area of ​​the filter plate 105 by cutting through the recesses 142a of the edge support end 142, but also to facilitate welding by inserting the protruding portions 142b of the edge support end 142 into the welding holes formed in the filter plate 105, thereby forming a predetermined air layer from the front of the filter plate 105 to the back of the ceramic waveguide filter 120.

[0093] In this way, by utilizing the edge support ends 142 of the separating bodies 141, 142, the ceramic waveguide filter 120 is separated from the front of the filter plate 105 by a predetermined distance, thereby forming an air layer, and the ceramic waveguide filter 120 is uniformly supported relative to the front of the filter plate 105.

[0094] On the other hand, the input port support portion and the output port support portion 143 may be formed into a shape in which openings or protrusions are repeatedly formed along the opposite direction to the edge support end 142 of the separation portion body 141, 142.

[0095] Preferably, the edge support ends 142 of the partition bodies 141 and 142, and the ends of the input port support and output port support 143, are at the same height from one side of the support plate 141. This is to ensure that the multiple ceramic waveguide filters 120 stacked in front of the support plate 141 are at a uniform height by separating the support plate 141 of the partition bodies 141 and 142 from the filter plate 105 by the same distance.

[0096] Multiple welding grooves 137 can be formed in the filter plate 105 for inserting or positioning the protrusions 142b of the edge support ends 142 of the partition body 141, 142 respectively. Welding can be achieved only when solder paste is applied to the ends of the edge support ends 142 of the partition body 141, 142 that are inserted and fixed to the multiple welding grooves 137.

[0097] The solder paste, which is used to bond the front surfaces of the partition bodies 141 and 142 and the filter plate 105 by welding, is not applied to all areas of the front surface of the filter plate 105. Instead, it is applied only to a portion corresponding to the protrusions of the edge support ends 142 in the structure of the partition bodies 141 and 142, as described above. This is because it minimizes the welding area compared to applying solder paste to all areas of the filter plate 105.

[0098] On the other hand, such as Figures 3 to 6 As shown, in order to provide a pair of input port support parts and output port support parts 143 on the same surface, bandpass filter port receiving parts 145 cut in a circular shape can be provided on the separating parts bodies 141 and 142 respectively.

[0099] Among them, such as Figure 5 and Figure 7As shown, for the microstrip line filter 130 which is provided as a low-pass filter on the filter board 105, in the bandpass filter port receiving portion 145, the same position as the input port hole portion of the ceramic waveguide filter 120 is configured as input port position 131a, and the position extending from the input port position 131a in a predetermined pattern shape and independent of the output port hole portion of the ceramic waveguide filter 120 is configured as output port position 131b.

[0100] The input port of the ceramic waveguide filter 120, which serves as the bandpass filter, and the input port 131a of the microstrip line filter 130, which serves as the low-pass filter, are located in the same bandpass filter port receiving portion 145. Although not shown, the input port terminal of the motherboard 110 is used as a medium to allow communication with the input port 131a of the microstrip line filter 130 without creating a short circuit, and to receive the power supply signal. In this case, a short circuit with the outside can be prevented by either the input port support portion or the output port support portion 143.

[0101] On the other hand, in the air layer forming sheet 140, a low-pass filter loop receiving portion 149 for accommodating a microstrip line filter serving as a low-pass filter 130 can be formed by cutting through the spacer body 141, 142. More specifically, the low-pass filter loop receiving portion 149 is formed to share the shape of the input position of the power supply signal in the structure of the microstrip line filter serving as the low-pass filter 130 with the above-mentioned bandpass filter port receiving portion 145, and is formed by cutting from the input port position 131a of the microstrip line filter serving as the low-pass filter 130 to the output port position serving as the output position.

[0102] Furthermore, in the air layer forming sheet 140, a signal line cutting portion 150 can be formed in the partition body 141, 142, starting from the bandpass filter port receiving portion 145 formed at a position corresponding to the output port hole in the structure of the ceramic waveguide filter 120, and extending to the end of the support plate portion 141. A signal line related to the output signal path can be housed inside the signal line cutting portion 150.

[0103] More in detail, such as Figure 7 As shown, the microstrip line filter 130, which is a low-pass filter, is made of a conductive material and may include an input port position 131a, an output port position 131b, and a patterned part 133 that connects the two in a non-cutting manner.

[0104] A portion of the pattern shape section 133 will function as a transmission line for transmitting signals from the input port position 131a to the output port position 131b. A portion of the pattern shape section 133 may form a repeating shape of capacitor lines 135a and 135b that function as capacitors and inductor line 135c that function as an inductor.

[0105] That is, in the microstrip line filter 130, a capacitor line 135a acting as a capacitor, a capacitor line 135b arranged side by side and spaced apart from the capacitor line 135a, and an inductor line 135c connecting the capacitor line 135a and the capacitor line 135b can be repeatedly formed within a predetermined range. The patterned portion 133 of the microstrip line filter 130, which serves as the low-pass filter, can be entirely housed inside the low-pass filter loop receiving portion 149 in the air layer forming sheet 140.

[0106] As mentioned above, the filter board 105 may be made of either a dielectric material or a ceramic material, which raises concerns about insertion loss in the microstrip line filter that serves as the low-pass filter 130.

[0107] To prevent the insertion loss as described above, such as Figure 9 As shown in portions (a) and (b), a spacer cutout 137 in the shape of a hole or slot can be formed in the filter plate 105 to separate all or part of the inductor line 135c from the front of the filter plate 105. Therefore, the insertion loss of the microstrip filter 130 caused by the material of the filter plate 105 can be minimized, thereby improving the overall performance of the filter product.

[0108] Figure 10 For along Figure 2a The sectional view taken by the BB line.

[0109] like Figure 10 As shown, in an antenna radio frequency filter assembly 100 according to an embodiment of the present invention, a filter board 105 can be stacked in front of the motherboard 110, and multiple radio frequency filters 100 can be installed in front of the filter board 105.

[0110] Among them, a microstrip line filter, which is a type of low-pass filter 130, among multiple radio frequency filters 100 can be printed on the front of the filter board 105 in an integral manner, and multiple ceramic waveguide filters, which are types of band-pass filters 120 among multiple radio frequency filters 100, are stacked and arranged with an air layer forming sheet 140 as a medium at a predetermined distance from the front of the filter board 105.

[0111] As described above, by forming an air layer 140, the microstrip line filter 130, which is integrally formed on the front of the filter plate 105, and the back of the ceramic waveguide filter 120, which is a bandpass filter, are separated from each other to form a predetermined air layer, thereby minimizing the insertion loss.

[0112] Figure 11 To illustrate the RF characteristics of the ceramic waveguide filter, Figure 12 To illustrate the RF characteristics of the microstrip line filter, Figure 13 To show and use Figure 11 Ceramic waveguide filters and Figure 12 A scatter plot of the radio frequency characteristics of the microstrip line filter in the state.

[0113] like Figure 11 As shown, when a ceramic waveguide filter is used as a bandpass filter 120, due to the characteristics of the ceramic material, there is a problem of spurious distortion S on the outer edge of the passband. To eliminate this spurious distortion S in the bandpass filter 120, the following method is employed... Figure 12 The low-pass filter 130 shown above has radio frequency characteristics.

[0114] That is, such as Figure 12 As shown, spurious S-band will be generated around 5.3 GHz on the outer side of the passband, such as... Figure 13 As shown, if the suppression band of the microstrip line filter 130, which serves as the low-pass filter, is roughly designed to be around 5.3 GHz, the location where the spurious signal S initially occurs, then as... Figure 13 As shown, it is possible to design a suppression band outside the passband desired by the designer.

[0115] In particular, the antenna radio frequency filter assembly 100 of one embodiment of the present invention can minimize the insertion loss of the microstrip line filter 130 as a low-pass filter by forming an air layer sheet 140, thereby having the advantage of facilitating the design of the passband frequency of the desired frequency band.

[0116] The antenna radio frequency filter assembly of the present invention has been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the one described above, and various modifications and equivalent implementations can be made by those skilled in the art. Furthermore, the true scope of protection of the present invention should be defined according to the claims.

[0117] Industrial availability

[0118] The present invention provides an antenna radio frequency filter assembly that minimizes the insertion loss of the filter, improves assemblability and productivity.

Claims

1. An RF filter assembly for an antenna, characterized by, The antenna radio frequency filter assembly according to claim 1, wherein: a plurality of band pass filters are included; a filter board is laminated on the front surface of the main board to serve as a medium for combining the front surface of the main board with the band pass filters; a low pass filter includes a capacitor line serving as a capacitor on the front surface of the filter board and an inductor line serving as an inductor; the low pass filter performs filtering through adjacent coupling or cross-coupling of electrical signals flowing through the input port or the output port; and an air layer forming sheet is disposed between the filter board and the band pass filters to form a predetermined air layer between the front surface of the filter board and the back surface of the band pass filters. The low pass filter includes a microstrip line filter formed of a conductive material and exposed on the front surface of the filter board in an integrated manner, The microstrip line filter is printed on the front surface of the filter board in a predetermined pattern shape from the input position of the power signal to the output position, The air layer forming sheet is cut to form a low pass filter loop housing portion for housing the predetermined pattern shape of the microstrip line filter.

2. The RF filter assembly for antennas according to claim 1, characterized in that, The band pass filter includes a ceramic waveguide filter formed of a ceramic material.

3. The RF filter assembly for antennas according to claim 1, characterized in that, The filter board includes one of a dielectric material and an FR4 material.

4. The RF filter assembly for antennas according to claim 1, characterized in that, The air layer forming sheet is formed of a metal material or a dielectric.

5. The antenna radio frequency filter assembly according to claim 1, wherein: input ports and output ports for inputting and outputting power signals are respectively spaced apart on the back surface of the band pass filters, The air layer forming sheet is cut to form a band pass filter port housing portion for housing positions corresponding to the input ports and the output ports of the band pass filters, respectively.

6. The RF filter assembly for antennas according to claim 1, characterized in that, The air layer forming sheet includes: a separation body for separating the band pass filters from the front surface of the filter board by a predetermined distance; and input port support portions and output port support portions disposed inside the separation body to be spaced apart from the separation body so that portions corresponding to the input ports and the output ports for inputting and outputting power signals to the band pass filters are separated from the filter board.

7. The RF filter assembly for antennas according to claim 6, characterized in that, The separation body and the input port support portions and the output port support portions are respectively separated from the plurality of band pass filters at the same height.

8. The RF filter assembly for antennas according to claim 6, characterized in that, The separation body includes: a support plate portion attached to the back surface of the band pass filters in a surface contact manner; and edge support ends bent toward the front surface of the filter board at edge end portions of the support plate portion, respectively.

9. The RF filter assembly for antennas according to claim 8, characterized in that, The edge support ends are formed in a shape repeatedly having a recess and a protrusion along the edge end portions.

10. The antenna radio frequency filter assembly according to claim 1, wherein: in the microstrip line filter, one side capacitor line serving as the capacitor, another side capacitor line arranged side by side in a spaced-apart manner from the one side capacitor line, and the inductor line connecting the one side capacitor line and the another side capacitor line are repeatedly formed in a predetermined interval, a portion or all of the inductor line is separated from the front surface of the filter board.

11. The RF filter assembly for antennas according to claim 10, characterized in that, In the filter board described above, a partition cut portion in the shape of a hole or a groove is formed for partitioning all or a part of the inductor lines. In the filter board described above, a partition cut portion in the shape of a hole or a groove is formed for partitioning all or a part of the inductor lines.

Images