Filter for communication device

Abstract

The present invention relates to a filter for a communication device, comprising: a filter body having at least one cavity formed therein; at least one resonator having a leading edge extended by a predetermined length from one side of the filter body to the other side corresponding to the bottom surface of the cavity; and a tunable bar coupled to each of a plurality of tuning holes formed in the filter body so as to be in communication with each of the cavities, and capable of adjusting the frequency by changing the shape of a portion corresponding to the thickness direction of the tuning holes, thereby providing the advantage of easy frequency tuning and modification without the application of a tuning screw method or additional structures, and reducing the manufacturing cost of the product.

Description

Technology Field

[0001] The present invention relates to a filter for a communication device, and more specifically, to a filter for a communication device that facilitates the automation of frequency tuning and can reduce the production cost of the product. Background Technology

[0002] For decades, tuning screws have been used to vary the frequency characteristics of filters for communication devices; however, the use of tuning screws presents difficulties in automated production. Consequently, numerous studies and results regarding methods to vary (tune) the frequency of filters without using tuning screws have been filed and disclosed as patents.

[0003] More specifically, conventional filters for communication devices adopt a method of setting a target frequency for the filter and lowering that frequency; specifically, the frequency is lowered by increasing the capacitance by reducing the distance (gap) between the resonator in the cavity and the filter tuning cover.

[0004] However, there are frequent cases where the frequency needs to be raised again for fine-tuning after the filter tuning cover made of a conductive material (metal) has been deformed, and in this case, it is very difficult to restore the deformed filter tuning cover to raise the frequency.

[0005] Although additional structures are sometimes used to solve these problems, such structures make it difficult to maintain the filter's frequency characteristics consistently under high or low temperatures, resulting in no successful cases of actual commercialization. The problem to be solved

[0007] The present invention has been devised to solve the above-mentioned technical problem, and aims to provide a filter for communication devices that facilitates the automated design of frequency tuning by applying a tunable bar that is easy to change the shape of to each of a plurality of cavities.

[0008] In addition, another objective of the present invention is to provide a filter for communication devices that can significantly reduce production costs by omitting a configuration such as a nut for fixing a conventional tuning screw.

[0009] In addition, another objective of the present invention is to provide a filter for a communication device with improved PIMD performance by ensuring there is no incomplete contact between the tuning hole and the tunable bar.

[0010] The problems of the present invention are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0011] A filter for a communication device according to one embodiment of the present invention comprises: a filter body having at least one cavity formed therein; at least one resonator having a leading edge that extends a predetermined length from one side of the filter body to the other side corresponding to the bottom surface of the cavity; and a tunable bar that is coupled to each of a plurality of tuning holes formed in the filter body so as to be in communication with each of the cavities, and which causes a shape deformation of the outer surface of a portion exposed inside the cavity, including a portion corresponding to a range in the thickness direction of the tuning holes, thereby enabling frequency adjustment.

[0012] Here, the tunable bar may include a joining flange that is engaged with the outer edge of the tuning hole of the filter tuning cover, a downward frequency adjustment part that extends from the joining flange through the tuning hole into the cavity of the filter body and includes a downward tuning surface arranged parallel to a resonant disk panel provided in the resonator, and an upward frequency adjustment part defined between the downward frequency adjustment part and the joining flange.

[0013] In addition, the downward frequency adjustment section and the upward frequency adjustment section are formed to have the same diameter and may be spaced apart and parallel to the inner end of the tuning hole.

[0014] In addition, the downward frequency adjustment part may be formed with a smaller diameter than the upward frequency adjustment part, and may be formed with a step difference relative to the upward frequency adjustment part.

[0015] In addition, the upward frequency adjustment unit may be formed such that its diameter gradually decreases as it extends toward the inside of the cavity.

[0016] In addition, the tuning hole corresponding to the position of the upward frequency adjustment part may include a tapered section formed such that the diameter gradually increases toward the cavity side.

[0017] In addition, a frequency measurement hole communicating with the cavity may be further formed at the center of the downward tuning surface.

[0018] In addition, frequency tuning modification through the upward frequency adjustment section of the tunable bar can be performed by a rotary compression jig that is introduced into the interior of the upward frequency adjustment section and rotates to shape the inner surface of the upward frequency adjustment section outward.

[0019] In addition, frequency tuning modification through the upward frequency adjustment section of the above-mentioned tunable bar can be performed by an expanding compression jig that is introduced into the interior of the upward frequency adjustment section and then spreads outward toward two or more points of the upward frequency adjustment section, thereby deforming the shape of the inner surface of the frequency adjustment section outward.

[0020] Additionally, frequency adjustment within the cavity is achieved through deformation of the inner surface or downward tuning surface of the downward frequency adjustment unit, and modification of the frequency adjusted by the downward frequency adjustment unit can be achieved through deformation of the inner surface of the upward frequency adjustment unit.

[0021] Additionally, the tunable bar includes a joining flange that is press-fitted into the inner end of the tuning hole, and the joining flange may have a plurality of cutting portions formed in the circumferential direction so that a predetermined tension force is continuously provided to the inner end of the tuning hole after being press-fitted into the tuning hole.

[0022] In addition, the outer surface of the above-mentioned joining flange may be formed with knurling.

[0023] In addition, in the portion corresponding to the upward frequency adjustment part, at least two frequency adjustment protrusions may protrude to a predetermined depth from the inner center.

[0024] In addition, in the portion corresponding to the upward frequency adjustment section, a plurality of frequency adjustment slits may be formed at spaced intervals in the circumferential direction, which penetrate inward and outward and are formed long in the vertical direction.

[0025] Additionally, it further includes a gap connecting the upper end of the upward frequency adjustment section and the joining flange, and the gap may be formed to protrude further in the outer direction of the tuning hole.

[0026] In addition, the tuning hole may be formed in a filter tuning cover provided to cover the other side of the filter body that is open. Effects of the invention

[0028] According to a filter for a communication device according to one embodiment of the present invention, the effect of facilitating the automated design of frequency tuning can be achieved.

[0029] In addition, the present invention can achieve the effect of reducing product production costs by eliminating the nut for fixing conventional tuning screws.

[0030] In addition, since the present invention has a structure in which there is no incomplete contact between the filter tuning cover and the tunable bar, it is possible to achieve the effect of improving PIMD performance that degrades filter performance. Brief explanation of the drawing

[0031] FIG. 1 is a cross-sectional view showing a filter for a communication device according to one embodiment of the present invention, and FIGS. 2a to 2g are drawings showing the installation of a tunable bar according to the first to seventh embodiments of the present invention, and FIG. 3 is a cross-sectional view showing the downward adjustment (a) and upward adjustment (b) of frequency tuning using a tunable bar in the configuration of FIG. 1, and FIG. 4 is a cross-sectional view showing a modified example of the filter tuning cover in the configuration of FIG. 1, and Figure 5 is a cross-sectional view showing the up-tuning of frequency tuning using various up-tuning tools. Specific details for implementing the invention

[0032] Hereinafter, a filter for a communication device according to one embodiment of the present invention will be described in detail with reference to the attached drawings.

[0033] It should be noted that when assigning reference numerals to the components of each drawing, the same components are assigned the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted.

[0034] In describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are intended merely to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by such terms. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0036] FIG. 1 is a cross-sectional view showing a filter for a communication device according to one embodiment of the present invention.

[0037] A filter (1) for a communication device according to the present invention comprises, as referenced in FIG. 1, a filter body (10) having at least one cavity (C) formed inside, at least one resonator (30) having a leading edge extended by a predetermined length from one side of the filter body (10) corresponding to the bottom surface of the cavity (C) to the other side, and a tunable bar (100) coupled to a tuning hole (25) formed in the filter body (10) so as to be in communication with each of the at least one cavity (C), and capable of adjusting the frequency by causing a shape deformation of the outer surface of the portion exposed into the cavity (C) including a portion corresponding to the thickness direction of the tuning hole (25).

[0038] More specifically, although not shown in the drawing, a plurality of cavities (C) are provided inside the filter body (10), partitioned by a partition wall or window not shown, and a plurality of resonators (30) may be provided inside each cavity (C) to function by changing individual frequency characteristics.

[0039] The resonator (30) may include a resonant bar (31) having its tip extended toward the side where the filter tuning cover (20) is located, which is open from the bottom surface (bottom surface) of the cavity (C) of the filter body (10), and a resonant disc panel (32) provided at the tip of the resonant bar (31) and formed in the shape of a metal panel wider than the diameter of the resonant bar (31).

[0040] Meanwhile, the other side facing the bottom surface (bottom) of the cavity (C) of the filter body (10) may be formed to be open, and a filter tuning cover (20) may be provided to cover the open other side of the filter body (10). However, the other side of the filter body (10) does not necessarily have to be formed to be open, and it is also possible to provide it to be shielded depending on the manufacturing method of the filter body (10).

[0041] Here, when configured to cover the other side of the filter body (10) that is open by the filter tuning cover (20), the tuning hole (25) may be formed in the filter tuning cover (20), and when the filter body (10) is formed such that the other side is shielded by itself, the tuning hole (25) may be formed to penetrate the shielded surface constituting the other side of the filter body (10). At this time, a plurality of the above-described tunable bars (100) may be installed in the tuning holes (25) formed at positions corresponding to each resonator (30) or individual cavity (C). Hereinafter, the description will be based on the premise that the plurality of tuning holes (25) are formed in the filter tuning cover (20) that is provided to cover the other side of the filter body (10).

[0042] Here, the plurality of tuning holes (25) are the parts where the plurality of tunable bars (100) are installed, and can be formed in the shape of circular holes that communicate with the outside of the filter body (10) or filter tuning cover (20) and the cavity (C).

[0043] The tunable bar (100) installed in the tuning hole (25) may have its outer surface spaced a predetermined distance from the inner end of the tuning hole (25). More specifically, the tuning hole (25) is formed to correspond to the thickness of the filter body (10) or the filter tuning cover (20), and may be spaced a predetermined distance from the inner end of the tuning hole (25) in a direction orthogonal to the thickness direction so as to form an inner capacitance between the outer surface of the tunable bar (100) and the length corresponding to the thickness of the tuning hole (25).

[0044] FIGS. 2a to 2g are drawings showing the installation of a tunable bar according to the first to seventh embodiments of the present invention. More specifically, (a) of FIGS. 2a to 2g is a cross-sectional view showing the installation of a tunable bar (100A to 100G) according to each embodiment in a tuning hole (25) of a filter body (10) or a filter tuning cover (20), (b) of FIGS. 2a to 2g is a front view of a tunable bar (100A to 100G) according to each embodiment, and (c) of FIGS. 2a to 2g is a bottom view of a tunable bar (100A to 100G) according to each embodiment.

[0045] A filter (1) for a communication device according to one embodiment of the present invention may include a tunable bar (100) according to a first to fourth embodiment, which includes a joining flange (110) that is engaged and joined to the outer edge of a tuning hole (25) of a filter body (10) or a filter tuning cover (20), as referenced in FIGS. 2a to 2d.

[0046] Additionally, the tunable bar (100A to 100D) according to the first to fourth embodiments may further include a downward frequency adjustment section (120D) that extends from the bonding flange (110) through the tuning hole (25) into the cavity (C) of the filter body (10) and includes a downward tuning surface (120B) arranged parallel to the resonant disk panel (32) of the resonator (30), and an upward frequency adjustment section (120U) defined between the downward frequency adjustment section (120D) and the bonding flange (110).

[0047] The joining flange (110) of the tunable bar (100A~100D) according to the first to fourth embodiments is bent orthogonally outward from the top of the upward frequency adjustment unit (120U) and performs the function of fixing the tunable bar (100) to the filter body (10) or filter tuning cover (20) corresponding to the peripheral edge end of the tuning hole (25) in various joining methods including soldering.

[0048] The filter (1) for a communication device according to the present invention can adjust the frequency upward or downward by modifying the shape of at least one of the up-frequency adjustment part (120U) and the down-frequency adjustment part (120D) of the tunable bar (100) and adjusting the capacitance, which is an electrical property, within the cavity (C).

[0049] The features of the tunable bars (100A to 100D) according to the first to fourth embodiments are described in detail below.

[0050] First, as referenced in FIG. 2a, the tunable bar (100A) according to the first embodiment is formed in a cylindrical shape with the same inner diameter for the remaining portion excluding the joint flange (110) portion, and the bottom portion received within the cavity (C) may be formed to be shielded to form a downward tuning surface (120B). Here, the downward frequency adjustment portion (120D) and the upward frequency adjustment portion (120U) may be defined as the portion closer to the cavity (C) based on an arbitrary dividing point (see horizontal dotted line) without physical distinction in their external shape, and the upward frequency adjustment portion (120U) may be defined as the portion between the joint flange (110).

[0051] Since the inner diameter of the remaining parts excluding the joint flange (110) is the same, the downward frequency adjustment part (120D) and the upward frequency adjustment part (120U) may have the same diameter. Here, in the tunable bar (100A) according to the first embodiment, the joint flange (110) is caught on the outside of the tuning hole (25), so the outer diameter of the joint flange (110) is formed larger than the tuning hole (25), and the outer diameters of the downward frequency adjustment part (120D) and the upward frequency adjustment part (120U) may be formed smaller than the inner diameter of the tuning hole (25).

[0052] Additionally, as referenced in FIG. 2b, the tunable bar (100B) according to the second embodiment may be formed such that the joining flange (110), the up-frequency adjustment section (120U), and the down-frequency adjustment section (120D) are externally distinguishable. More specifically, the joining flange (110) and the up-frequency adjustment section (120U) are distinguished by having different inner diameters or diameters, as in the tunable bar (100A) according to the first embodiment described above, and the diameters of the up-frequency adjustment section (120U) and the down-frequency adjustment section (120D) may also be formed with different steps to be externally distinguishable. Here, the diameter of the down-frequency adjustment section (120D) may be formed to be relatively smaller than the diameter of the up-frequency adjustment section (120U). Therefore, in the tunable bar (100B) according to the second embodiment, the outer diameter of the joining flange (110) is formed to be larger than the tuning hole (25), and the outer diameter of the upward frequency adjustment part (120U) is formed to be smaller than the inner diameter of the tuning hole (25), but larger than the outer diameter of the downward frequency adjustment part (120D).

[0053] In addition, as referenced in FIG. 2c, the tunable bar (100C) according to the third embodiment is formed such that the external shape of the joining flange (110), the upward frequency adjustment part (120U), and the downward frequency adjustment part (120D) are distinct, and the downward frequency adjustment part (120D) can also be formed such that the external shape is distinct by forming a stepped shape with a different diameter by means of a stepped part. More specifically, the joining flange (110) and the upward frequency adjustment part (120U) are formed to have different inner diameters or diameters, as in the tunable bar (100A, 100B) according to the first and second embodiments described above, and the diameters of the upward frequency adjustment part (120U) and the downward frequency adjustment part (120D) are also formed to be different from each other and thus externally distinguishable, and the downward frequency adjustment part (120D) can also be formed to have different diameters within a predetermined upper and lower range and thus externally distinguishable.

[0054] And, as referenced in FIG. 2d, the tunable bar (100D) according to the fourth embodiment may be provided in a cone shape such that the diameter gradually decreases as the upward frequency adjustment section (120U) moves toward the downward frequency adjustment section (120D) which is equipped with a cavity (C). Here, the tunable bar (100D) according to the fourth embodiment is formed such that the diameter continuously decreases from the top of the upward frequency adjustment section (120U) to the bottom of the downward frequency adjustment section (120D). Although the upward frequency adjustment section (120U) and the downward frequency adjustment section (120D) are not externally distinguished, the upper side may be defined as the upward frequency adjustment section (120U) based on an arbitrary line in an upper and lower range that is approximately greater than the thickness of the filter body (10) or the filter tuning cover (20), and the lower side may be defined as the downward frequency adjustment section (120D) based on an arbitrary line.

[0055] Typically, metal filters are designed to be positioned higher than the target frequency, and the frequency is adjusted by lowering the resonant frequency of the filter using a tuning screw or the like. However, in the case of the communication device filter of the present invention, when a frequency tuning designer (hereinafter abbreviated as "designer") uses a tuning tool (not shown) to expand and deform the inner surface (inner side) of the downward frequency adjustment part (120D) outward, the area is widened accordingly, the capacitance is changed, and the frequency is lowered. If necessary, the frequency may also be lowered by reducing the distance from the resonant disk panel (32) of the resonator (30) by pressing (or striking) the downward tuning surface (120B), which corresponds to the horizontal plane of the downward frequency adjustment part (120D), using a tuning tool (not shown).

[0056] In the aforementioned frequency down-adjustment process, if the frequency is adjusted downward more than the target frequency, the designer can finely adjust the frequency upward by applying an external force outward to the inner surface (inner side) corresponding to the up-frequency adjustment part (120U) using a tuning tool. When the inner surface (inner side) corresponding to the up-frequency adjustment part (120U) is deformed, the distance (gap) between the inner surface (inner side) corresponding to the up-frequency adjustment part (120U) and the filter tuning cover decreases, the capacitance changes, and the frequency is raised accordingly.

[0057] Meanwhile, as referenced in (a) of FIG. 2a, the joint flange (110) portion of the configuration of the tunable bar (100) may be joined in various ways including soldering after being seated on the periphery portion of the tuning hole (25) of the filter body (10) or filter tuning cover (20).

[0058] At this time, a plurality of welded portions (115), each partially cut into an arc shape, are formed in the joint flange (110) at a distance from each other in the circumferential direction, and by applying solder material to the welded portions (115), the tunable bar (100) can be firmly fixed to the filter tuning cover (20) (see FIG. 2a).

[0059] Meanwhile, a filter (1) for a communication device according to one embodiment of the present invention may further include a tunable bar (100E) according to a fifth embodiment, comprising a bonding flange (110) that is engaged and bonded to the outer edge of a tuning hole (25) of a filter body (10) or a filter tuning cover (20) as referenced in FIG. 2e, a downward frequency adjustment part (120D) that extends into a cavity (C) of the filter body (10) and includes a downward tuning surface (120B) arranged parallel to a resonant disk panel (32) of a resonator (30), an upward frequency adjustment part (120U) defined as the upper part of the downward frequency adjustment part (120D), and a spacing part (111) connecting the upper part of the upward frequency adjustment part (120U) and the bonding flange (110).

[0060] Here, as referenced in FIG. 2e, the tunable bar (100E) according to the fifth embodiment may be formed such that the spacing space between the inner end forming the tuning hole (25) and the filter body (10) or filter tuning cover (20) is further extended to the outside of the filter body (10) or filter tuning cover (20) by the spacing portion (111) described above, so that the area forming the internal capacitance described above can be further increased and maximized.

[0061] More specifically, in the tunable bar (100E) according to the fifth embodiment, assuming that the joining flange (110) is formed by bending it parallel to the outer surface of the filter body (10) or filter tuning cover (20) corresponding to the outer edge end of the tuning hole (25), the gap (111) that performs an internal capacitance function by connecting the joining flange (110) and the end of the up frequency adjustment part (120U) can be formed to protrude further outward than the outer surface of the filter body (10) or filter tuning cover (20) by extending a predetermined length outwardly parallel to the inner circumference end of the tuning hole (25) from at least the top of the up frequency adjustment part (120U).

[0062] At this time, the tunable bar (100E) according to the fifth embodiment, although not shown in the drawing, can be soldered together using a solder material applied between the outer end of the joining flange (110) and the outer surface of the filter body (10) or the filter tuning cover (20), similar to the tunable bars (100A to 100D) according to the first to fourth embodiments.

[0063] Meanwhile, the tunable bar (100E) according to the fifth embodiment is formed on the downward tuning surface (120B) corresponding to the downward frequency adjustment section (120D), and a frequency measurement hole (120h) formed to communicate with the cavity (c) so that measurement by a frequency meter (not shown) between the resonator (30) and the tunable bar can be formed in the form of a boss hole or a through hole.

[0064] Such a frequency measurement hole (120h) is preferably formed in the center portion of the downward tuning surface (120B), and can be formed in the same way not only in the tunable bars (100A~100D) according to the first to fourth embodiments described above, but also in the tunable bars (100F, 100G) according to the sixth and seventh embodiments described later.

[0065] A filter (1) for a communication device according to one embodiment of the present invention may further include a tunable bar (100F, 100G) according to a sixth and seventh embodiment, comprising a bonding flange (110') that is press-fitted into the inner end of a tuning hole (25) of a filter body (10) or a filter tuning cover (20) as referenced in FIG. 2f and FIG. 2g, a downward frequency adjustment part (120D) that extends into a cavity (C) of the filter body (10) and includes a downward tuning surface (120B) arranged parallel to a resonant disk panel (32) of a resonator (30), an upward frequency adjustment part (120U) defined as the upper part of the downward frequency adjustment part (120D), and a spacing part (111) connecting the upper end of the upward frequency adjustment part (120U) and the bonding flange (110').

[0066] Here, as referenced in FIG. 2f and FIG. 2g, the tunable bar (100F, 100G) according to the 6th and 7th embodiments may be defined as an embodiment in which the joining flange (110') is bent and formed parallel to the upward frequency adjustment part (120U), and the outer surface is joined to the inner end of the tuning hole (25) formed in the filter body (10) or filter tuning cover (20).

[0067] In the case of the tunable bars (100A to 100E) according to the first to sixth embodiments referenced in FIGS. 2a to 2e, the joining flange (110) is formed in a circular shape larger than the tuning hole (25), so it may be difficult to accurately match and fix the center of the tunable bars (100A to 100E) with the center of the resonant disk panel (32). On the other hand, in the case of the tunable bars (100F, 100G) according to the sixth and seventh embodiments, the design is modified so that the direct joining flange (110') is fitted into the inner circumference of the tuning hole (25), and thus the center of the tunable bars (100F, 100G) can be fixed to match the center of the resonant disk panel (32) within the cavity (C) solely through the fitting operation itself.

[0068] At this time, the joint flange (110') may further have a plurality of cutting portions (112) formed at a distance from each other in the circumferential direction, which are cut downwards so that a predetermined tension force is continuously provided to the inner end of the tuning hole (25) after being forcibly fitted into the tuning hole (25) of the filter body (10) or the filter tuning cover (20).

[0069] In addition, at least two frequency adjustment protrusions (125P) protruding to a predetermined depth from the inner center may be further formed in the portion corresponding to the upward frequency adjustment section (120U). Referring to FIGS. 2f and 2g, the tunable bar (100F, 100G) according to the 6th and 7th embodiments is illustrated and described as having four frequency adjustment protrusions (125P) spaced 90 degrees apart in the circumferential direction, but is not necessarily limited thereto, and may be adopted in a suitable number that is advantageous for the external shape deformation of the tunable bar (100F, 100G).

[0070] The designer can increase the frequency by using a tuning tool to push the frequency adjustment projection (125P) formed to protrude inward inward inward, thereby deforming the shape.

[0071] Meanwhile, as referenced in FIG. 2g, the tunable bar (100G) according to the 7th embodiment is formed such that the joining flange (110') is press-fitted into the inner end of the tuning hole (25), just like the tunable bar (100F) according to the 6th embodiment described above, and the outer surface of the joining flange (110') in contact with the inner end of the tuning hole (25) is formed with knurling to further enhance the adhesion and fixing force (refer to reference numeral '110'-1' in FIG. 2g).

[0072] Here, in the part corresponding to the upward frequency adjustment section (120U), multiple frequency adjustment slits (125s) are formed at spaced intervals in the circumferential direction, penetrating inward and outward and extending in the vertical direction, and the designer can adjust the frequency upward by deforming the outer shape using a tuning tool (not shown) that is caught through the frequency adjustment slits (125s).

[0073] At this time, the tunable bar (100F) according to the 6th embodiment and the tunable bar (100G) according to the 7th embodiment can be soldered together using a solder material applied between the gap portion (111) and the outer edge of the tuning hole (25) of the filter tuning cover (20), although this is not shown in the drawing.

[0074] FIG. 3 is a cross-sectional view showing downward adjustment (a) and upward adjustment (b) of frequency tuning using a tunable bar in the configuration of FIG. 1, FIG. 4 is a cross-sectional view showing a modified example of a filter tuning cover in the configuration of FIG. 1, and FIG. 5 is a cross-sectional view showing the upward adjustment of frequency tuning using various upward adjustment tools.

[0075] The frequency tuning design and frequency correction process after tuning using the down-frequency adjustment unit (120D) and up-frequency adjustment unit (120U) of the tunable bar (100) implemented in various embodiments as described above will be explained with reference to the attached drawings (particularly FIG. 3). FIG. 3 illustrates the frequency tuning design and frequency correction process after tuning based on the tunable bar (100D) according to the fourth embodiment, but the same principle can be applied to tunable bars (100) according to other embodiments.

[0076] As referenced in FIG. 3(a), the frequency tuning operation of a specific cavity (C) is performed by changing the capacitance through downward shape deformation (if necessary) of the inner surface (inner side) and / or the downward tuning surface (120B) of the downward frequency adjustment section (120D) using a predetermined tuning tool (not shown) to lower the frequency.

[0077] At this time, the distance (D1) between the lower surface of the tunable bar (100D) and the resonant disc panel (32) may be a preset value representing the frequency characteristics required by the designer. An operator or automatic tuning device performing frequency adjustment may apply an external force to the inner surface (inner side) and / or the downward tuning surface (120B) of the downward frequency adjustment unit (120D) until the value D1 described above is reached, thereby causing a shape deformation to reach the value D1, and may store the result value when the desired value is reached.

[0078] However, if the shape is deformed downward more than the D1 value, the frequency tuning correction process must be performed, and the operator or automatic tuning device performing the frequency correction can apply an external force to the inner surface of the upward frequency adjustment part (120U) to form a tuning correction point (120P2) so as to reach the D1 value again as referenced in FIG. 3 (b), and deform the shape until it reaches the D2 value, while simultaneously strengthening the capacitance with the filter tuning cover (20) to weaken the capacitance corresponding to the D1 value, thereby moving the frequency upward as a result.

[0079] However, the frequency correction process does not necessarily have to be performed only through an external force on the upward frequency adjustment unit (120) described above. When the frequency correction process described above is performed, a correction point (120P1) is formed in the part corresponding to the downward frequency adjustment unit (120D), and an upward shape deformation can be caused.

[0080] Meanwhile, for the installation of the tunable bar (100D), the tuning hole (25) formed in the filter body (10) or filter tuning cover (20) may include a tapered section (27) formed such that the diameter gradually increases towards the inside of the cavity (C), as referenced in FIG. 4.

[0081] By ensuring a sufficient distance from the outer surface of the upward frequency adjustment section (120U) of the tunable bar (100D) through the tapered section (27), it has the advantage of being able to easily utilize the internal capacitance.

[0082] In addition, frequency tuning modification through the upward frequency adjustment unit (120U) of the above-described tunable bar (100D) can be performed using a rotary compression jig (200-1) or an extended compression jig (200-2), as referenced in FIG. 5 (a) and (b).

[0083] More specifically, as referenced in FIG. 5(a), frequency tuning correction through the upward frequency adjustment section (120U) of the tunable bar (100D) can be performed by slightly raising the lower surface of the tunable bar (100D) while causing an external deformation such as a correction point (120P2) as the jig tip (210) that applies external force to the inner surface corresponding to the upward frequency adjustment section (120U) is rotated.

[0084] Additionally, as referenced in FIG. 5(b), frequency tuning modification through the upward frequency adjustment section (120U) of the tunable bar (100D) can be performed by slightly raising the bottom surface of the tunable bar (100D) while causing external deformation such as the modification point (120P2) on both sides, using an expansion compression jig (200-2) which is configured such that the compression tips (220), which are introduced into the interior of the upward frequency adjustment section (120U) and then separated from each other, spread out toward two or more points of the upward frequency adjustment section (120U).

[0085] In one embodiment of the present invention, the tunable bar (100D) is preferably made of a metal material that is easy to plastically deform, such as aluminum or copper, so that the shape of the upward frequency adjustment part (120U) can be easily deformed as described above.

[0086] A filter (1) for a communication device according to one embodiment of the present invention can completely eliminate the incomplete contact phenomenon between the filter tuning cover (20) and the tunable bar (100D), thereby improving the PIMD problem that degrades the performance of the filter, and also provides the advantage of reducing the production (manufacturing) cost of the product because a separate tuning screw (not shown) or additional structure (e.g., a fixing nut for fixing the tuning screw) is not required.

[0088] For the above, a filter for a communication device according to one embodiment of the present invention has been described in detail with reference to the attached drawings. However, the embodiments of the present invention are not necessarily limited to the above-described embodiment, and it is obvious that various modifications and implementations within an equivalent scope are possible by those skilled in the art to which the present invention belongs. Therefore, the true scope of the rights of the present invention shall be determined by the claims set forth below. Explanation of the symbols

[0090] 1: Filter for communication devices 10: Filter body 20; Filter tuning cover 25: Tuning hole 27: Taper stage 30: Resonator 31: Resonance bar 32: Resonance disk panel 100: Tunable bar 110,110': Connecting flange 111: Separation section 112: Cutting section 115: Welding part 120: Frequency adjustment part 120D: Down-frequency adjuster 120U: Up-frequency adjuster 120B: Downward tuning surface 120h: Frequency measurement hole 125P: Frequency adjustment protrusion 125s: Frequency adjustment slit

Claims

Claim 1 A filter body having at least one cavity formed therein; at least one resonator positioned such that its leading edge extends a predetermined length from one side of the filter body's bottom surface corresponding to the bottom surface of the cavity to the other side; and a tunable bar coupled to each of a plurality of tuning holes formed in the filter body so as to be in communication with each of the cavities, and capable of adjusting the frequency by causing a shape deformation of the outer surface of a portion exposed into the cavity, including a portion corresponding to a range in the thickness direction of the tuning holes; wherein the tunable bar comprises: a joining flange press-fitted to the inner circumference of the tuning hole; a downward frequency adjustment part extending from the joining flange through the tuning hole into the cavity of the filter body and including a downward tuning surface arranged parallel to a resonant disk panel provided in the resonator; and an upward frequency adjustment part defined between the downward frequency adjustment part and the joining flange. A filter for a communication device comprising, wherein frequency adjustment within the cavity is achieved through deformation of the inner surface or downward tuning surface of the downward frequency adjustment unit, and modification of the frequency adjusted by the downward frequency adjustment unit is achieved through deformation of the inner surface of the upward frequency adjustment unit in the outward direction. Claim 2 A filter for a communication device according to claim 1, wherein the joining flange is formed by bending parallel to the upward frequency adjustment part and the outer surface is joined to the inner circumference of the tuning hole. Claim 3 A filter for a communication device according to claim 2, wherein the down-frequency adjustment unit and the up-frequency adjustment unit are formed to have the same diameter and are spaced apart parallel to the inner end of the tuning hole. Claim 4 A filter for a communication device according to claim 2, wherein the down-frequency adjustment part is formed with a smaller diameter than the up-frequency adjustment part and is formed with a step difference relative to the up-frequency adjustment part. Claim 5 In claim 2, the up-frequency adjustment portion is a filter for a communication device formed such that its diameter gradually decreases as it extends toward the inside of the cavity. Claim 6 A filter for a communication device according to claim 2, wherein the tuning hole corresponding to the position of the up-frequency adjustment part is formed such that its diameter gradually increases toward the cavity side. Claim 7 A filter for a communication device according to claim 2, wherein a frequency measurement hole communicating with the cavity is further formed at the center of the downward tuning surface. Claim 8 A filter for a communication device according to claim 2, wherein frequency tuning modification through the up-frequency adjustment unit of the tunable bar is performed by a rotary compression jig that is introduced into the interior of the up-frequency adjustment unit and rotates to shape-deform the inner surface of the up-frequency adjustment unit outward. Claim 9 A filter for a communication device according to claim 2, wherein frequency tuning modification through the up-frequency adjustment section of the tunable bar is performed by an expansion compression jig that is introduced into the interior of the up-frequency adjustment section and then spreads outward toward two or more points of the up-frequency adjustment section, thereby deforming the shape of the inner surface of the frequency adjustment section outward. Claim 10 delete Claim 11 A filter for a communication device according to claim 1, wherein the joining flange has a plurality of circumferentially cut sections formed therein so that a predetermined tension force is continuously provided to the inner end of the tuning hole after being press-fitted into the tuning hole. Claim 12 A filter for a communication device according to claim 11, wherein the outer surface of the joining flange is formed by knurling. Claim 13 A filter for a communication device according to claim 2, wherein the portion corresponding to the up-frequency adjustment part has at least two frequency adjustment protrusions protruding to a predetermined depth from the inner center. Claim 14 A filter for a communication device according to claim 2, wherein in the portion corresponding to the upward frequency adjustment part, a plurality of frequency adjustment slits are formed circumferentially spaced apart, penetrating inwardly and outwardly and formed by cutting long in the vertical direction. Claim 15 A filter for a communication device according to claim 2, further comprising a spacing portion connecting the upper end of the upward frequency adjustment portion and the joining flange; wherein the spacing portion is formed to protrude further in the direction outward of the tuning hole. Claim 16 A filter for a communication device according to claim 2 or claim 11, wherein the tuning hole is formed in a filter tuning cover provided to cover the other side of the filter body that is open.

Images