Filter for communication device

Abstract

The utility model relates to a filter for communication equipment, in particular to the filter for the communication equipment, which comprises a filter main body, at least one cavity serving as a predetermined space is formed inside the filter main body, and one side of the filter main body is opened; a filter tuning cover configured to cover one side of the opening of the filter body and formed with a plurality of screw mounting holes; a plurality of tuning screws which are fastened to the plurality of screw mounting holes, respectively, and which adjust the spacing distance from the tip of the resonator disposed inside the cavity; and a guide nut inserted into a screw mounting hole for the filter tuning cover to mount the tuning screw. Wherein the filter for a communication device forms at least one solder paste coating slot (hereinafter referred to as a "solder slot" for short) formed in any one of the plurality of tuning screws and the guide nut, and the solder paste coating slot (hereinafter referred to as a "solder slot") is formed in any one of the plurality of tuning screws and the guide nut. After the frequency is tuned by each of the plurality of tuning screws, a solder material for bonding the plurality of tuning screws to the screw mounting holes is inserted.

Description

Technical Field

[0001] The utility model relates to a filter for communication equipment, and more specifically, to a filter for communication equipment that minimizes the PIMD (Passive Intermodulation Distortion) phenomenon and can improve communication quality. Background Art

[0002] With the evolution of mobile communication technology, the data transmission speed has increased exponentially. In order to improve the receiving and transmitting sensitivity as the data transmission increases, there is a trend that the transmission power of the base station gradually increases.

[0003] The receiving and transmitting filter or duplexer, which is used as a necessary device to prevent interference between the receiving and transmitting terminals in the base station, is mainly realized by using a coaxial resonator made of a metal material with high power resistance to withstand high power.

[0004] In addition, the filter used in a mobile communication base station requires accurate and uniform frequency characteristics. Therefore, due to the mechanical tolerances generated during the manufacturing and assembly of each component, the characteristics become very sensitive. Therefore, a metal tuning screw is used to adjust the resonance frequency on the upper cover of the housing that constitutes the coaxial resonator, and thus the filtering characteristics required by the filter can be realized.

[0005] On the other hand, in a filter that is a passive component, intermodulation distortion signals may appear in the non-linear characteristics caused by incomplete metal contact, metal debris, dust, etc., which is called PIMD (Passive Intermodulation Distortion).

[0006] Figure 1 is an exploded perspective view showing a general passive component filter; Figure 2 is shown in Figure 1 a cross-sectional view of the tuning structure formed by the metal tuning screw in the structure of

[0007] As Figure 1 and Figure 2 shown, the existing passive component filter 1 has: a housing 2 with a cavity C formed inside; at least one resonator 3 disposed in the cavity C; a tuning cover 5 coupled to the open upper side of the housing 2; a tuning screw 7 penetrating and installed in a screw mounting hole 6 formed in the tuning cover 5; and a nut 8 for locking the tuning screw 7 in a position where the frequency adjustment is completed.

[0008] Recently, in order to further apply to a higher frequency band (several hundred MHz) based on the capacitance using the distance D between the resonator 3 and the tuning screw 7, there is a tendency to flexibly utilize the capacitance of the spaced space formed between the inner peripheral end of the screw mounting hole 6 formed in the tuning cover 5 and the outer peripheral surface of the tuning screw 7.

[0009] However, in Figure 1 andFigure 2 The actual situation of the shown frequency tuning structure is that, with respect to the direct friction of the screw assembly method of the tuning screw 7 formed on the outer peripheral surface of the tuning screw 7 against the screw mounting hole 6, from this point of view, discontinuous contact is generated, and gold-plated powder (fine metal powder) can be generated due to the friction between the tuning screw 7 and the screw mounting hole 6 during the frequency tuning process, and this metal powder is the main cause of PIMD occurrence.

[0010] In particular, for the filter for communication equipment, usually up to dozens of tuning screws 7 are used to adjust the frequency characteristics. From this point of view, there are the following problems: it is difficult to fundamentally eliminate the PIMD problem, or it is difficult to ensure that each product has the same characteristics, and products that are difficult to optimize through repair or rework are to be discarded.

[0011] In addition, the confirmation of PIMD performance can only be carried out after confirming all the performances of the product. Therefore, there is a problem of generating more time and cost compared to the repair of ordinary non-compliant products. SUMMARY OF THE UTILITY MODEL

[0012] (Problems to be solved)

[0013] The present utility model is proposed to solve the above technical problems, and the purpose is to provide a filter for communication equipment that can minimize the occurrence of PIMD.

[0014] At the same time, another object of the present utility model is to provide a filter for communication equipment as follows: a solder paste coating slot (welding slot) is formed, and the tuning screw that has completed frequency tuning (adjustment) can be easily fixed to the filter tuning cover by a welding method.

[0015] The problems of the present utility model are not limited to the problems mentioned above, and for other problems not mentioned, those skilled in the technical field to which the present utility model belongs can clearly understand from the following description.

[0016] (Means for solving the problems)

[0017] A filter for a communication device according to an embodiment of the present invention includes: a filter body having at least one cavity formed therein as a predetermined space and open at one side; a filter tuning cover configured to cover the open side of the filter body and formed with a plurality of screw mounting holes; a plurality of tuning screws respectively fastened to the plurality of screw mounting holes and adjusting the distance from the front end of a resonator disposed inside the cavity; and a guide nut interposed between the tuning screws and mounted to the screw mounting holes for the filter tuning cover; wherein, the filter for the communication device forms at least one solder paste coating slot (hereinafter, simply referred to as "welding slot"), the welding slot is formed in any one of the plurality of tuning screws and the guide nut, and after tuning the frequencies respectively by the plurality of tuning screws, a solder material for welding and bonding the plurality of tuning screws to the screw mounting holes is inserted.

[0018] Herein, the welding slot is formed in the guide nut and can be formed to remove at least a part of the female thread of the nut that fastens to the male thread formed on the outer circumferential surface of the tuning screw.

[0019] In addition, the welding slot is formed in the guide nut and can be formed to remove a part of the end portion in contact with the filter tuning cover in the radial direction.

[0020] In addition, the screw mounting hole includes a mounting boss protruding a predetermined length in the outer direction of the filter tuning cover; a female thread of the boss can be formed on the inner circumferential surface of the mounting boss, and the female thread of the boss fastens to the male thread formed on the outer circumferential surface of the tuning screw.

[0021] In addition, the female thread of the mounting boss of the filter tuning cover can be made by a burring tap method.

[0022] In addition, the guide nut includes: a boss receiving portion configured to surround the mounting boss of the screw mounting hole; and a screw fastening portion having a female thread of the nut formed on the inner circumferential surface for fastening the tuning screw; the welding slot can be formed to remove the female thread of the screw fastening portion in the fastening direction of the tuning screw.

[0023] In addition, the guide nut includes: a boss receiving portion configured to surround the mounting boss of the screw mounting hole; a screw fastening portion having a female thread of the nut formed on the inner circumferential surface for fastening the tuning screw; the welding slot can be formed to cut a part of the guide nut including the boss receiving portion and the screw fastening portion to expose the tuning screw from the outer end to the inner side.

[0024] In addition, the outer peripheral surface of the mounting boss includes an inner tapered portion, and the inner tapered portion has a diameter that gradually decreases toward the outer end; the inner peripheral surface of the boss receiving portion of the guide nut may include an outer tapered portion, and the outer tapered portion is formed to have an inclination angle corresponding to the inner tapered portion of the mounting boss.

[0025] In addition, in the outer side surface or the inner side surface of the filter tuning cover corresponding to the end portion of the boss receiving portion of the guide nut, an upper tuning groove portion or a lower tuning groove portion can be formed by cutting with a thickness smaller than that of the filter tuning cover.

[0026] In addition, the welding slot is formed in the tuning screw and can be formed to remove at least a part of the male thread formed on the outer peripheral surface of the tuning screw.

[0027] In addition, the welding slot can be formed in a straight line in the tightening direction with respect to the screw mounting hole.

[0028] In addition, an additional space step portion can be formed at least at one of the upper end portion and the lower end portion of the guide nut, and the additional space step portion is formed by step cutting to include a part of the welding slot.

[0029] In addition, after the tuning screw and the filter tuning cover are welded and fixed through the welding slot, frequency readjustment can be performed according to the rotation direction of the guide nut.

[0030] In addition, an upper tuning groove portion is further formed on the outer side surface of the filter tuning cover, and the upper tuning groove portion is formed such that the maximum radius is smaller than the distance from the center of the screw mounting hole to the outer side surface of the guide nut; in the upper tuning groove portion, a step portion can be further formed at the peripheral portion of the screw mounting hole with a depth smaller than that of the upper tuning groove portion.

[0031] In addition, when the materials of the filter main body and the filter tuning cover are aluminum or aluminum alloy, the material of the guide nut is composed of a material having a higher high-frequency reactivity than the materials of the filter main body and the filter tuning cover made of aluminum or aluminum alloy.

[0032] In addition, the screw mounting hole includes a mounting boss, and the mounting boss is formed such that the inner side frame end protrudes into the cavity interior by a flanging and tapping method; a female thread of the boss can be formed on the inner peripheral surface of the mounting boss to fasten the male thread formed on the outer peripheral surface of the tuning screw.

[0033] (Effects of the utility model)

[0034] The filter for a communication device according to an embodiment of the present utility model can achieve the following various effects.

[0035] First, the gap between the screw mounting hole and the tuning screw is completely filled by welding, fundamentally eliminating the incomplete contact between the tuning screw and the screw mounting hole of the filter tuning cover, and thus having the effect of fundamentally eliminating the occurrence of PIMD.

[0036] Second, welding fixation using a solder material is performed through a welding slot integrated with the guide nut or the tuning screw. Thus, the tuning screw will not become loose, so there is no need for strong torque locking. Instead, the filter tuning cover can be made of thin material, thus having the effects of reducing the product weight and saving the manufacturing cost.

[0037] Third, the tuning screw is fixed by welding, eliminating the need for coating with separate screw-fixing epoxy resin, etc., and thus having the effect of saving the manufacturing cost of the product.

[0038] Fourth, the guide nut is made of a metal or heat-resistant plastic that is difficult to weld, such as SUS (stainless steel), etc. From this perspective, the tuning screw can be removed (separated) even after the tuning screw is welded and fixed to the filter tuning cover. Therefore, it has the effect of being reusable after welding and fixation.

[0039] Fifth, usually, after frequency tuning, the tuning screw is fixed to the filter tuning cover by welding. In this way, frequency readjustment cannot be performed. However, different from this prior art, it has the effect of being able to additionally readjust the frequency of the filter even after the tuning screw is welded and fixed to the filter tuning cover or when the frequency characteristics change during the manufacturing process. Description of the Drawings

[0040] Figure 1 is an exploded perspective view showing a general passive component filter;

[0041] Figure 2 is showing Figure 1 a sectional view of a tuning structure using a metal tuning screw in the structure of

[0042] Figure 3 is a sectional view showing a filter for a communication device according to an embodiment of the present utility model;

[0043] Figure 4a is showing Figure 3 a partially enlarged view of the mounting form of the tuning screw in the structure of

[0044] Figure 4b is Figure 4a an exploded perspective view of

[0045] Figure 5 is showing Figure 3Cross-sectional views (a), plan views (b), and bottom views (c) of various implementations of the welding slot in the structure;

[0046] Figure 6 show Figure 5 Cross-sectional views (a) and plan views (b) showing the welding pattern of the welding slot according to the third implementation in the structure;

[0047] Figure 7 show Figure 3 Cross-sectional views (a), plan views (b), cross-sectional views (a), plan views (b), and side views (c) of another implementation of the welding slot in the structure and of the tuning screw;

[0048] Figure 8 show Figure 3 Plan views and cross-sectional views of another implementation of the welding slot in the structure;

[0049] Figure 9 Cross-sectional views (a) and plan views (b) of a filter for a communication device according to another embodiment of the present invention, and cross-sectional views (a), plan views (b), and bottom views (c) of a partial structure (guide nut);

[0050] Figure 10 Cross-sectional view showing the locking process of the guide nut of a filter for a communication device according to another embodiment of the present invention;

[0051] Figure 11 Cross-sectional view showing the fine tuning after the tuning screw of a filter for a communication device according to an embodiment of the present invention is fixed;

[0052] Figure 12 show Figure 3 Cross-sectional views and plan views of various embodiments of the groove portion of the filter tuning cover in the structure;

[0053] Figure 13 Cross-sectional views and plan views showing a modified example of the groove portion of the filter tuning cover in the case where a guide nut without a separately provided boss receiving portion is applied;

[0054] Figure 14 apply Figure 3 Plan views and cross-sectional views of another modified example of the mounting boss in the structure;

[0055] (Explanation of reference numerals)

[0056] C: Cavity 10: Filter housing

[0057] 20: Filter body 30: Filter tuning cover

[0058] 31: Tuning screw 31-1: Male thread

[0059] 32: Guide nut 32-1: Female thread of nut

[0060] 32a: Boss receiving portion 32a-2: Outer tapered portion

[0061] 32b: Screw fastening portion 35: Screw mounting hole

[0062] 35a: Mounting boss 35-1: Female thread of boss

[0063] 35-2: Inner tapered portion 37a: Upper tuning slot portion

[0064] 37b: Lower tuning slot portion 40: Resonator

[0065] 41: Resonant body 42: Resonator disk panel

[0066] 50: Welding slot 51a to 51e: Welding slots

[0067] 55: Solder material (solder paste) Detailed implementation mode

[0068] Hereinafter, a filter for a communication device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0069] When assigning reference numerals to the components in each drawing, for the same components, it should be noted that even if they are shown in different drawings, they should preferably have the same reference numerals. In addition, when describing the embodiments of the present invention, if it is determined that the specific description of related well-known structures or functions hinders the understanding of the embodiments of the present invention, the specific description will be omitted.

[0070] When describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. Such terms are only used to distinguish one component from other components and shall not limit the nature or order of the components by the terms. In addition, unless otherwise defined, all terms used herein including technical or scientific terms have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having the same meaning as in the relevant technical articles, and unless clearly defined in this application, they should not be interpreted in an ideal or overly formal sense.

[0071] Figure 3 is a cross-sectional view showing a filter for a communication device according to an embodiment of the present invention; Figure 4a shows Figure 3 a partially enlarged view of the installation form of the tuning screw in the structure of

[0072] The filter 1 for a communication device according to the present utility model relates to a technical feature of minimizing fine metal powder generated during the process of adjusting (tuning) the frequency using a tuning screw 31 described later, and further minimizing the occurrence of PIMD, and can be implemented by various embodiments and implementation examples as follows.

[0073] First, referring to Figures 3 to 4b , the filter 1 for a communication device according to the present utility model may include a filter housing 10 in which at least one cavity C having a predetermined space is formed inside.

[0074] The filter housing 10 may include: a filter main body 20, which is generally open at the upper part in the drawing and is formed in a shape opening one side of the cavity C; a filter tuning cover 30, which is coupled to close the opening side of the filter main body 20 and is formed with a plurality of screw mounting holes 35 for mounting a plurality of tuning screws 31 described later.

[0075] Generally, each resonator 40 described later disposed in the cavity C is tuned in frequency by one tuning screw 31. From this point of view, it is preferably designed such that the number of tuning screws 31 is the same as the number of resonators 40.

[0076] Here, the outer surface of the filter housing 10 and the inner surfaces of the filter main body 20 and the filter tuning cover 30 forming the cavity C may be configured in a form of being entirely coated with a film made of a predetermined metal material.

[0077] At this time, the metal material constituting the film may be aluminum (or aluminum alloy), and the materials of the filter main body 20 and the filter tuning cover 30 in the case where the film is not formed are also preferably aluminum (or aluminum alloy) materials.

[0078] On the other hand, the filter 1 for a communication device according to the present utility model may further include a plurality of resonators 40, and the plurality of resonators 40 are fixed to the bottom surface of the cavity C formed by the filter main body 20 of the filter housing 10 and are arranged such that the front ends extend toward the opening side of the cavity C.

[0079] Each of the plurality of resonators 40 may include a resonator main body 41 and a resonator disc panel 42. The resonator disc panel 42 is configured in a panel shape having a diameter larger than that of the resonator main body 41 and is integrally combined or separately manufactured and combined at the front end adjacent to the filter tuning cover 30.

[0080] Here, as Figures 3 to 4bAs shown, the filter 1 for a communication device according to the present utility model further includes a plurality of tuning screws 31. The plurality of tuning screws 31 are configured to be movable in the up-and-down direction at least inside the cavity C, so that the upper and lower ends can be located at positions spaced above the resonator disc panel 42 in the drawing.

[0081] The plurality of tuning screws 31 are made of a metal material as a conductive material. By adjusting the distance from the upper surface of the resonator disc panel 42 in the cavity C, the resonant frequency characteristics desired by the designer can be generated.

[0082] On the other hand, the plurality of tuning screws 31 are installed by a screw assembly method for each of the plurality of screw mounting holes 35. As the tuning screws 31 rotate in one direction and the other direction, the height of the lower end can be adjusted in the drawing to adjust the resonant frequency characteristic value in the cavity C.

[0083] In particular, the tuning screw 31 can be directly thread-assembled into the screw mounting hole 35. However, as Figures 3 to 4b shown, of course, it can be installed in the screw mounting hole 35 of the filter tuning cover 30 through a guide nut 32.

[0084] Here, the filter 1 for a communication device according to the present utility model can form a solder paste coating slot (hereinafter, simply referred to as "welding slot"). The welding slot is formed in any one of the plurality of tuning screws 31 and the guide nut 32. After the frequencies are respectively tuned by the plurality of tuning screws 31, a solder material is inserted to weld and bond the plurality of tuning screws 31 to the screw mounting holes 35.

[0085] The welding slot 50 not only serves as a part for providing the coating of the solder paste, which is one of the welding materials (solder materials), but also serves to weld and fix the tuning screw 31 and the filter tuning cover 30 when the solder paste is melted by exposure to high temperature.

[0086] As described above, the welding slot 50 as described above can be formed integrally with the guide nut 32 or can be formed integrally with the tuning screw 31. Hereinafter, according to the implementation example, the welding slot 50 formed in the guide nut 32 is defined as the nut-side welding slots 51a, 51b, 51c, and the welding slot 50 formed in the tuning screw 31 is defined as the screw-side welding slot 52 for description.

[0087] Figure 5 It shows Figure 3 cross-sectional view (a), plan view (b) and bottom view (c) of various implementation examples of the welding slot in the structure of; Figure 6 It shows Figure 5 cross-sectional view (a) and plan view (b) of the welding form of the welding slot according to the third implementation example in the structure of; Figure 7Shows Figure 3 A sectional view (a), a plan view (b) of another implementation example of the welding slot in the structure shown, and a sectional view (a), a plan view (b) and a side view (c) of the tuning screw.

[0088] First, the case where the nut-side welding slots 51a, 51b, 51c are integrally formed with the guide nut 32 will be described as follows.

[0089] As Figure 5 And Figure 6 Shown, the guide nut 32 is formed to have an outer side surface with various horizontal cross-sections such as a substantially hexagonal or quadrilateral shape, and is formed to have a hollow penetrating the middle part in the up-down direction. On the inner peripheral surface corresponding to this hollow, a female nut thread 32-1 can be machined to fasten the male thread 31-1 formed on the outer peripheral surface of the tuning screw 31.

[0090] The guide nut 32 as described above can be made of metal or heat-resistant plastic. When made of a metal material, gold plating treatments such as nickel plating or chromium plating can be performed to prevent it from being welded and fixed together when welded and fixed to the tuning screw 31 and the filter tuning cover 30 described later.

[0091] However, when welding and fixing the tuning screw 31 using the welding slot 50 of the guide nut 32, it is impossible to rule out the method of melting the solder material 55 by a high-frequency heater (not shown). Therefore, in this case, the material of the guide nut 32 can be a metal with high high-frequency reactivity (for example, a metal such as carbon steel or STS430, which is a material for a magnet vertically attached to less than 500G).

[0092] At this time, the material of the solder material 55 usually uses low-melting-point low-temperature lead. When the same low-temperature lead is used as the welding material for the filter tuning cover 30 with respect to the filter body 20, the high-frequency reactivity of the filter body 20 and the filter tuning cover 30 made of aluminum (or aluminum alloy) material is relatively lower than that of the guide nut 32.

[0093] Therefore, assuming that the filter body 20 and the filter tuning cover 30 are heated to 100°C at the same frequency output, the solder material (low-temperature lead) 55 in the welding slot 50 welded and joined by the guide nut 32 with high high-frequency reactivity can be easily raised above the melting point, thus preventing the solder material (low-temperature lead) for welding and joining the filter body 20 and the filter tuning cover 30 made of aluminum material with relatively low high-frequency reactivity from melting excessively, and further preventing the problem of RF characteristics changing in advance.

[0094] For reference, as described later, the tuning screw 31 and the filter tuning cover 30 must be fixed by a soldering method using a solder material. From this point of view, different from the guide nut 32, it is required to be formed of a material that is easily solder-fixed or to be pre-fixed by gold plating for soldering.

[0095] Here, the nut-side welding slots 51a, 51b, 51c may include: the welding slot 51a of the first implementation example, as Figure 5 shown in (a) of, is formed in a groove shape that removes a part of the female nut thread 32-1 formed in the hollow part of the guide nut 32; the welding slot 51b of the second implementation example, as Figure 5 shown in (b) of, is formed in a slot shape that connects the outer side surface and the hollow of the guide nut 32; the welding slot 51c of the third implementation example, as Figure 5 shown in (c) of, is formed to remove a part of the end portion in contact with the filter tuning cover 30 in a radius portion.

[0096] On the other hand, as Figures 3 to 6 shown, the filter 100 for a communication device according to the present utility model may further include a screw mounting hole 35 formed in the filter tuning cover 30 to mount (or fasten) the tuning screw 31 to the filter tuning cover 30.

[0097] The screw mounting hole 35 is formed in a circular hole shape that communicates the outer space of the filter tuning cover 30 and the cavity C, and a female thread (the boss female thread 35-1 described later) may be formed at the inner peripheral end (the surface forming the thickness) for fastening to the male thread 31-1 formed on the outer peripheral surface of the tuning screw 31.

[0098] Here, the screw mounting hole 35 may also be formed in a simple hole shape, as Figure 4a and Figure 4b shown, as a boss shape, it may be configured to include a shape of a mounting boss 35a that protrudes a predetermined length in the outer side direction of the filter tuning cover 30.

[0099] The above-mentioned boss female thread 35-1 is machined on the inner peripheral surface of the mounting boss 35a, and the boss female thread 35-1 is made (machined) for the filter tuning cover 30 by a burring tap method.

[0100] When the screw mounting hole 35 is machined in the filter tuning cover 30 by the burring tap method as described above, it is easy to manufacture the boss female thread 35-1 at the inner peripheral end of the screw mounting hole 35 of the filter tuning cover 30 that is manufactured in a relatively thin thickness specification. Moreover, it reflexively provides a filter tuning cover 30 that can adopt a thinner thickness specification.

[0101] As described above, on the premise that the screw mounting hole 35 is configured in a boss shape, as Figure 3 and Figure 5 shown in the first and second implementation examples, the guiding nut 32 may include a boss receiving portion 32a and a screw fastening portion 32b. The boss receiving portion 32a is configured to surround the mounting boss 35a of the screw mounting hole 35, and a female nut thread 32-1 for fastening the male thread 31-1 of the tuning screw 31 is formed on the inner peripheral surface of the screw fastening portion 32b.

[0102] However, as Figure 5 shown in the third implementation example, when the guiding nut 32 is structured to fix the tuning screw 31 fastened to the screw mounting hole 35 having a simple hole shape without the mounting boss 35a formed, there is no need to separately provide the boss receiving portion 32a.

[0103] Here, as Figure 5 shown, the welding slot 51a of the first implementation example can be formed in a shape that removes the female nut thread 32-1 formed on the hollow inner peripheral surface of the screw fastening portion 32b except for the boss receiving portion 32a of the screw mounting hole 35 as Figures 3 to 4b shown.

[0104] In addition, as Figure 5 shown, the welding slot 51b of the second implementation example can be formed in a shape that removes the female nut thread 32-1 to include the boss receiving portion 32a of the screw mounting hole 35 as Figures 3 to 4b shown.

[0105] At this time, as described above, the difference in the welding slot 51b of the second implementation example is that it is formed in a slot shape that connects the outer side surface of the guiding nut 32 to the hollow.

[0106] However, the welding slot 51c of the third implementation example, in the case where the screw mounting hole 35 of the filter tuning cover 30 is formed with the female nut thread 32-1 without the boss receiving portion 32a, is formed to remove a part of the end portion of the guiding nut 32 in contact with the filter tuning cover 30 in the radial direction, and can be formed to cut a part of the guiding nut 32 to expose the tuning screw 31 from the outer side end to the inner side.

[0107] If the frequency adjustment is completed by the action of fastening the tuning screw 31 to the screw mounting hole 35, after applying the solder material (solder paste) 55 through the welding slots 51a to 51c of the above various implementation examples and maintaining for a predetermined time in a high-temperature environment (or, a predetermined high-frequency environment), the solder material 55 melts and the tuning screw 31 and the filter tuning cover 30 can be fixed to each other by welding.

[0108] At this time, asFigure 4a As shown, the solder material 55 applied through the welding slot 51a of the first embodiment and the welding slot 51b of the second embodiment, in the state of being applied to the front end of the mounting boss 35a of the screw mounting hole 35, melts in a high-temperature environment and simultaneously penetrates and fills the space between the female thread 35-1 formed on the inner circumferential surface of the mounting boss 35a and the male thread 31-1 of the tuning screw 31. Furthermore, the generation of fine metal powder, which is the deep-rooted cause of the PIMD problem, can be completely eliminated.

[0109] In addition, as Figure 6 shown, the solder material applied through the welding slot 51c of the third embodiment, in the state of being applied between the outer frame end of the screw mounting hole 35 and the tuning screw 31, melts in a high-temperature environment and can penetrate and fill the space between the female thread 35-1 and the male thread 31-1 of the tuning screw 31.

[0110] Figure 7 is a cross-sectional view (a), a plan view (b) of another embodiment of the welding slot in the structure of Figure 3 and a cross-sectional view (a), a plan view (b) and a side view (c) of the tuning screw; Figure 8 is a plan view and a cross-sectional view of another embodiment of the welding slot in the structure of Figure 3 shown.

[0111] Referring to Figures 3 to 6 the welding slots 51a to 51c of the various embodiments described are formed in the guide nut 32 of the embodiment.

[0112] Then, it is not necessary for the welding slot 50 to be only in the shape in the guide nut 32. Instead, as Figure 7 shown, it can also be formed in the tuning screw 31 or in the filter tuning cover 30.

[0113] More specifically, as Figure 7 shown, another embodiment of the welding slot 51d is formed in the tuning screw 31 and can be formed to remove at least a part of the male thread 31-1 formed on the outer circumferential surface of the tuning screw 31.

[0114] The welding slot 51d as described above can be formed to be linear in the tightening direction for tightening the tuning screw 31 against the screw mounting hole 35.

[0115] In addition, as Figure 8 shown, another embodiment of the welding slot 51e can be formed by cutting a part of the outer side surface of the filter tuning cover 30.

[0116] At this time, the cutting range of the soldering slot 51e in another implementation example is a part of the surface of the cutting guide nut 32 that contacts the filter tuning cover 30, and is cut at least more in the radial direction than the outer side surface of the guide nut 32, so that the solder material 55 can be easily inserted and coated.

[0117] Figure 9 FIG. (a) and FIG. (b) are cross-sectional views, FIG. (a) and FIG. (b) are plan views, and FIG. (c) is a bottom view showing a partial structure (guide nut) of a filter for a communication device according to another embodiment of the present invention; Figure 10 FIG. is a cross-sectional view showing the locking process of the guide nut of the filter for a communication device according to another embodiment of the present invention.

[0118] As Figure 9 and Figure 10 shown, for the filter 1 for a communication device according to another embodiment of the present invention, on the premise that the screw mounting hole 35 is formed to include a mounting boss 35a and the guide nut 32 also has a boss receiving portion 32a surrounding the mounting boss 35a, the outer peripheral surface of the mounting boss 35a includes an inner tapered portion 35-2, and the inner tapered portion 35-2 gradually reduces in diameter toward the outer end (i.e., the direction away from the outer side surface of the filter tuning cover 30). The inner peripheral surface of the boss receiving portion 32a of the guide nut 32 may include an outer tapered portion 32a-2, and the outer tapered portion 32a-2 is formed to have an inclination angle corresponding to the inner tapered portion 35-2 of the mounting boss 35a.

[0119] As Figure 10 shown, for the filter 1 for a communication device according to another embodiment of the present invention as described above, when the tuning screw 31 is locked to the mounting boss 35a by the guide nut 32 after adjusting the frequency by the tuning screw 31, the stronger the locking force of the guide nut 32 acts, the closer the outer tapered portion 32a-2 of the guide nut is to the inner tapered portion 35-2 of the mounting boss 35a, and thus the force pushing the mounting boss 35a toward the tuning screw 31 becomes greater. Therefore, the gap between the outer peripheral surface of the tuning screw 31 and the inner peripheral surface (boss female thread 35-1) of the mounting boss 35a is reduced.

[0120] As described above, for the filter 1 for a communication device according to the present invention, the screw mounting hole 35 is not a simple hole shape but includes a mounting boss 35a, so that a material with a relatively thin thickness of the filter tuning cover 30 can be used for manufacturing. Therefore, the weight of the product can be reduced, and an additional advantage of cost savings in manufacturing can be provided.

[0121] Figure 11It is a cross-sectional view showing fine tuning after the tuning screw of the filter for a communication device according to an embodiment of the present invention is fixed; Figure 12 It shows Figure 3 Cross-sectional views and plan views of various embodiments of the groove portion of the filter tuning cover in the structure of; Figure 13 It is a cross-sectional view and a plan view showing a modification example of the groove portion of the filter tuning cover in the case where a guide nut without a separately provided boss accommodating portion is applied; Figure 14 It is applicable Figure 3 Plan views and cross-sectional views of another modification example of the mounting boss in the structure of.

[0122] As Figure 11 shown, the filter 1 for a communication device according to an embodiment of the present invention is fixed after adjusting the frequency using the tuning screw 31, and the gap of the screw mounting hole 35 for the filter tuning cover 30 is completely filled with the solder material 55. In this way, it may be difficult to additionally perform fine frequency adjustment.

[0123] However, in the case of the filter 1 for a communication device according to an embodiment of the present invention, since the filter tuning cover 30 can be manufactured with a relatively thin material, after fixing the tuning screw 31 to the filter tuning cover 30, as Figure 11 shown, fine adjustment of the frequency can also be performed along the rotation direction of the tuning screw 31.

[0124] More specifically, after fixing the tuning screw 31 to the screw mounting hole 35 of the filter tuning cover 30 with the solder material 55 and then forcibly rotating the guide nut 32 to one side or the other, actually the tuning screw 31 does not rotate, but the force that slightly pulls up or pushes down the filter tuning cover 30 corresponding to the inner part of the boss accommodating portion 32a of the guide nut 32 by the rotational force provided by the user (designer) acts, and the tuning screw 31 can be moved up and down. Considerable frequency tuning can be performed within this fine movement range.

[0125] On the other hand, in the case where the filter tuning cover 30 has a relatively thick thickness, as Figure 12 shown, not only can an upper tuning groove 37a be formed on the upper surface of the filter tuning cover 30 corresponding to the periphery of the screw mounting hole 35 to accommodate a lower part of the lower end of the boss accommodating portion 32a, but also a lower tuning groove portion 37b can be formed on the lower surface of the filter tuning cover 30 corresponding to the lower end of the boss accommodating portion 32a.

[0126] In the case where the above-described upper tuning groove portion 37a or lower tuning groove portion 37b is additionally formed on the upper surface or lower surface of the filter tuning cover 30, fine frequency tuning can be performed by the action of slightly deforming the corresponding groove portion (37a or 37b) by the rotational force transmitted to the tuning screw 31.

[0127] The above-described upper tuning groove portion 37a and lower tuning groove portion 37b are structures on the premise that the guide nut 32 has a separate boss accommodating portion 32a.

[0128] On the contrary, according to the reference Figure 13 The upper tuning groove portion 37c of the modified example is, in the case of a normal form in which the guide nut 32 is not provided with a separate boss accommodating portion, formed around the screw mounting hole 35 of the filter tuning cover 30, and can be formed with a maximum radius smaller than the distance from the center of the screw mounting hole 35 to the outer side surface of the guide nut 32.

[0129] In addition, the upper tuning groove portion 37c according to the modified example may further form a stepped portion 37c-1 at the peripheral portion of the screw mounting hole 35 to ensure a sufficient range for screwing and fastening with the male thread 31-1 of the tuning screw 31, with a depth smaller than that of the upper tuning groove portion 37c.

[0130] As described above, in the case where the stepped portion 37c-1 is additionally formed in the upper tuning groove portion 37c according to the modified example, a sufficient screwing and fastening range of the tuning screw 31 can be ensured. Therefore, if the guide nut 32 is rotated to one side or the other after fixing by the soldering method of applying a solder material through the soldering slot 50, the tuning screw 31 can be moved up or down, so that the advantage of being able to stably perform fine frequency readjustment can be achieved.

[0131] More specifically, referring to Figure 13 If a solder material 55 is applied through the soldering slot 50 of the guide nut 32 and then exposed for a predetermined time in a high-temperature environment (or a high-frequency environment), the molten solder material 55 infiltrates into the gap between the male thread 31-1 formed on the outer peripheral surface of the tuning screw 31 and the female thread 35-1 of the boss of the screw mounting hole 35 in a soldering manner, and at the same time, the tuning screw 31 is fixed to the filter tuning cover 30 through the curing action.

[0132] Then, for further adjustment of the frequency characteristics, if the designer rotates the guide nut 32 in place in one direction or the other, a part of the lower end face of the guide nut 32 supports the outer side surface of the filter tuning cover 30, and at the same time, the inner part of the lower end face of the guide nut 32, which is relatively thinner than the thickness of the filter tuning cover 30, or the part corresponding to the upper tuning groove part 37c of the modification example is deformed in shape so as to be pulled upward or pushed downward (toward the cavity C side) in the drawing along the rotation direction of the tuning screw 31.

[0133] Here, when the upper tuning groove part 37c of the modification example is deformed upward, the distance between the lower end of the tuning screw 31 and the upper end of the resonator 40 in the cavity C is slightly increased while performing frequency readjustment. On the contrary, when the upper tuning groove part 37c of the modification example is deformed downward, the distance between the lower end of the tuning screw 31 and the upper end of the resonator 40 in the cavity C can be slightly decreased while performing frequency readjustment.

[0134] On the other hand, as Figure 12 shown, in the filter 1 for a communication device according to an embodiment of the present invention, additional space step parts 32c-1 and 32c-2 may be formed at least at one of the upper end part and the lower end part of the guide nut 32 so as to cut a part including the welding slot 50 in a stepped shape.

[0135] The additional space step parts 32c-1 and 32c-2 serve to ensure an additional space for filling a sufficient amount of solder material 55 when applying the solder material through the welding slot 50.

[0136] However, the additional space step parts 32c-1 and 32c-2 do not necessarily have to be cut in a stepped shape, but may also be formed obliquely within a range where sufficient space can be ensured.

[0137] Meanwhile, as Figure 3 shown, in the filter 1 for a communication device according to an embodiment of the present invention, the mounting boss 35a protrudes outward from the outer side surface of the filter tuning cover 30, but the forming direction of the mounting boss 35a is not limited to this.

[0138] If, as in another modification example with reference to Figure 14 shown, the mounting boss 35a may be formed such that the inner border end of the screw mounting hole 35 of the filter tuning cover 30 protrudes inward into the cavity C by flanging and tapping.

[0139] The inner peripheral surface of the mounting boss 35a here may also be formed with an internal thread 35-1 of the boss to fasten the external thread 31-1 formed on the outer peripheral surface of the tuning screw 31.

[0140] The mounting boss 35a according to another modification example described above also compensates for the disadvantages of the filter tuning cover 30 with a relatively thin thickness. It is easy to form an internal female thread 35-1 of the boss inside the screw mounting hole 35, and a thinner filter tuning cover 30 can be adopted. Therefore, it has the advantage of significantly reducing the total weight of the product.

[0141] As described above, the filter for a communication device according to an embodiment of the present invention has been described in detail with reference to the accompanying drawings. However, the embodiments of the present invention are not necessarily limited to the above-described embodiments, and can of course be variously modified and implemented within the equivalent scope by those having ordinary knowledge in the technical field to which the present invention pertains. Therefore, the true scope of the claims of the present invention should be determined by the scope of the claims.

Claims

1. A filter for a communication device, comprising: A filter body, having at least one cavity formed as a predetermined space therein and having an opening on one side; A filter tuning cover configured to cover the opening side of the filter body and having a plurality of screw mounting holes formed therein; A plurality of tuning screws respectively fastened to the plurality of screw mounting holes and adjusting the spacing distance from the front end of a resonator disposed inside the cavity; And A guide nut interposed for mounting the tuning screw to the screw mounting hole of the filter tuning cover; Wherein, the filter for the communication device forms at least one solder paste coating slot, the solder paste coating slot is formed in any one of the plurality of tuning screws and the guide nut, and after tuning the frequency respectively by the plurality of tuning screws, a solder material for welding and bonding the plurality of tuning screws to the screw mounting holes is inserted.

2. The filter for a communication device according to claim 1, wherein The solder paste coating slot is formed in the guide nut and is formed to remove at least a part of the female thread of the nut that fastens the male thread formed on the outer peripheral surface of the tuning screw.

3. The filter for a communication device according to claim 1, wherein The solder paste coating slot is formed in the guide nut and is formed to remove a part of the end portion contacting the filter tuning cover in the radial direction.

4. The filter for a communication device according to claim 1, wherein The screw mounting hole includes a mounting boss protruding a predetermined length in the outer direction of the filter tuning cover; A female thread of the boss is formed on the inner peripheral surface of the mounting boss, and the female thread of the boss fastens the male thread formed on the outer peripheral surface of the tuning screw.

5. The filter for a communication device according to claim 4, wherein The female thread of the mounting boss of the filter tuning cover is made by a flanging tapping method.

6. The filter for a communication device according to claim 4, wherein The guide nut includes: A boss accommodating portion configured to surround the mounting boss of the screw mounting hole; and A screw fastening portion having a female thread of the nut for fastening the tuning screw formed on the inner peripheral surface; The solder paste coating slot is formed to remove the female thread of the screw fastening portion in the fastening direction of the tuning screw.

7. The filter for a communication device according to claim 4, wherein The guide nut includes: A boss accommodating portion configured to surround the mounting boss of the screw mounting hole; and A screw fastening portion having a female thread of the nut for fastening the tuning screw formed on the inner peripheral surface; Wherein, the solder paste coating slot is formed to cut a part of the guide nut including the boss accommodating portion and the screw fastening portion to expose the tuning screw from the outer end to the inner side.

8. The filter for a communication device according to claim 6 or 7, wherein The outer peripheral surface of the mounting boss includes an inner tapered portion, and the inner tapered portion gradually reduces in diameter toward the outer end; The inner peripheral surface of the boss receiving portion of the guide nut includes an outer tapered portion, and the outer tapered portion is formed to have an inclination angle corresponding to the inner tapered portion of the mounting boss.

9. The filter for a communication device according to claim 6 or 7, wherein In the outer side surface or the inner side surface of the filter tuning cover corresponding to the end portion of the boss receiving portion of the guide nut, an upper tuning groove portion or a lower tuning groove portion is formed by cutting with a thickness smaller than that of the filter tuning cover.

10. The filter for a communication device according to claim 1, wherein The solder paste coating slot is formed in the tuning screw and is formed to remove at least a part of the male thread formed on the outer peripheral surface of the tuning screw.

11. The filter for a communication device according to claim 10, wherein The solder paste coating slot is formed linearly in the tightening direction with respect to the screw mounting hole.

12. The filter for a communication device according to claim 1, wherein An additional space step portion is further formed at at least one of the upper end portion and the lower end portion of the guide nut, and the additional space step portion is formed by step cutting to include a part of the solder paste coating slot.

13. The filter for a communication device according to claim 1, wherein After the tuning screw and the filter tuning cover are welded and fixed through the solder paste coating slot, frequency readjustment can be performed according to the rotation direction of the guide nut.

14. The filter for a communication device according to claim 1, wherein An upper tuning groove portion is further formed on the outer side surface of the filter tuning cover, and the upper tuning groove portion is formed such that the maximum radius is smaller than the distance from the center of the screw mounting hole to the outer side surface of the guide nut; In the upper tuning groove portion, a step portion is further formed at the peripheral portion of the screw mounting hole with a depth smaller than that of the upper tuning groove portion.

15. The filter for a communication device according to claim 1, wherein When the materials of the filter main body and the filter tuning cover are aluminum or aluminum alloy, The material of the guide nut is composed of a material having a higher high-frequency reactivity than the materials of the filter main body and the filter tuning cover made of aluminum or aluminum alloy.

16. The filter for a communication device according to claim 1, wherein The screw mounting hole includes a mounting boss, and the mounting boss is formed such that the inner side frame end protrudes into the cavity by a flanging and tapping method; A boss female thread is formed on the inner peripheral surface of the mounting boss to fasten the male thread formed on the outer peripheral surface of the tuning screw.

Images