Press-fit resonator, filter comprising same, and method for manufacturing filter

Abstract

The present invention relates to a press-fit resonator, a filter comprising same, and a method for manufacturing a filter, wherein the press-fit resonator is fixed to a resonance rod installation boss formed on the bottom surface of a cavity of a filter body in a press-fitting manner, and comprises an upper end bonding part to which a resonance disc panel is coupled, and a resonance rod body of which a lower end press-fit portion press-fitted onto the resonance rod installation boss has a tapered outer circumference. The press-fit resonator comprises a filter tuning cover which covers one open surface of the filter, wherein, when the press-fit resonator is bonded by solder cream applied after the press-fit resonator has been press-fitted onto the resonance rod installation boss, the filter tuning cover is also simultaneously bonded to the filter body by solder cream applied to the filter body, thus providing the advantages of minimizing the error range of frequency measurement and ensuring product quality.

Description

Pressure-type resonator, filter including same, and method for manufacturing filter

[0001] The present invention relates to a press-fitting resonator, a filter including the same, and a manufacturing method for the filter, and more particularly, to a press-fitting resonator capable of reducing an error in a resonator frequency and implementing unmanned automation of filter manufacturing, a filter including the same, and a manufacturing method for the filter.

[0002] Fig. 1 is a cross-sectional view showing the installation of a resonator rod according to a conventional technique and the measurement of the resonator rod frequency using a short pin.

[0003] In the prior art, as shown in Fig. 1, in order to fix a resonator (= resonator) (40) to a cavity (C) of a filter body (20) among the configurations of a filter housing (10), a hole is made in the center of a resonator disk panel (42), and a resonator (= resonator) (40) is screw-fastened to a resonator installation end (25) formed on the bottom surface of the cavity (C) of the filter body (20) through the hole using a fixing screw (43).

[0004] Here, the resonator (resonator) (40) is provided with a resonator body (41) and a resonator disk panel (42) provided on the upper end thereof, as shown in FIG. 1. In order to fasten the resonator body (41) to the resonator installation section (25) via the hollow portion of the resonator body (41) using the above-described fixing screw (43), the inner diameter of at least the central hole of the resonator disk panel (42) must be larger than the diameter of the head (not indicated in the drawing) of the fixing screw (43).

[0005] In this way, there is a problem that the larger the inner diameter of the central hole of the resonant disk panel (42), the smaller the amount of capacitance secured.

[0006] In addition, in order to measure the natural frequency of a specific resonator (resonator) (40), as shown in FIG. 1, all surrounding resonators (resonators) (40) (see (a) and (b) of FIG. 1) except for the resonator to be measured must be short-circuited. In order to install a tuning screw (not shown), a short pin (50A, 50B) must be deeply inserted through the center of the resonator body (41) through a screw installation hole (35) formed in the filter tuning cover (30).

[0007] Likewise, the diameter (H1) of the short pin (50A, 50B) here should be at least smaller than the inner diameter of the central hole of the resonant disk panel (42), and the maximum value can also be limited at least by the screw installation hole (35) of the filter tuning cover (30) and the hollow inner diameter (H2) of the resonant rod body (41).

[0008] However, as the length of the short pin (50A, 50B) for measuring the natural frequency increases, there is a problem that the error range in the frequency measurement of the resonant rod (40) to be measured increases, and as the error range of the frequency increases, there is a problem that signal loss of the entire filter (1) occurs.

[0009] In addition, the filter (1) according to the prior art can be assembled in one of the following two ways. First, referring to (a) of FIG. 1, 1) the resonant rod body (41) and the resonant disk panel (42) are welded, 2) the resonant rod (resonator) (40) is plated, 3) the resonant rod (resonator) (40) and the resonator installation end (25) are fastened and fixed using a fixing screw (43), 4) solder cream (34) is applied along the opened upper edge of the filter body (20) to combine the filter body (20) and the filter tuning cover (30), 5) the filter tuning cover (30) is heat-treated (welded) to be joined, and 6) the natural frequency can be measured using the above-described short pin (50B). The heat treatment here can be performed in both low-temperature and high-temperature atmospheres.

[0010] Next, referring to (b) of FIG. 1, 1) the resonator body (41) and the resonator disk panel (42) are welded, 2) the resonator (resonator) (40) is plated, 3) soldering of the resonator (resonator) (40) to the resonator mounting end (25) is applied to the upper end of the resonator mounting end (25), 4) soldering is performed using a high-temperature heat treatment bonding method, 5) the natural frequency of the resonator (resonator) (4) is measured using the short pin (50A) described above, 6) soldering of the filter body (20) and the filter tuning cover (30) is performed by applying solder cream (34) along the opened upper edge of the filter body (20), and 7) bonding is performed using a low-temperature heat treatment. The heat treatment temperature at this time is required to be low, and if it is high, there is a risk that the solder joint of the resonator rod (resonator) (40) and the resonator installation part (25) may melt.

[0011] The method of assembling and manufacturing a filter (1) according to the prior art, as shown in (a) of Fig. 1, has a problem in that in the case of fixing the filter body (20) and the resonator (resonator) (40) using a fixing screw (43), the method of coupling the filter tuning cover (30) to the filter body (20) is two-fold and must be fixed in a separate manner.

[0012]

[0013] The present invention has been devised to solve the above-mentioned technical problem, and its purpose is to provide a press-type resonator, a filter including the same, and a method for manufacturing the filter, which can minimize the angle tuning process to be performed later by reducing the error in measuring the natural frequency of the resonator.

[0014] In addition, another object of the present invention is to provide a press-fit type resonator, which is easy to manufacture and assemble by simply fixing the resonator to the resonator installation boss by force-fitting (or press-fitting) using a lower press-fit portion, and then simultaneously soldering the filter body together with the filter tuning cover, and a filter including the same, and a method for manufacturing the filter.

[0015] In addition, another object of the present invention is to provide a press-fit resonator, a filter including the same, and a method for manufacturing the filter, which can secure a high Q value for the same volume by minimizing the reduced area of ​​the resonant disk panel and securing the maximum capacitance capacity since the short pin does not need to pass through the center of the resonant disk panel when measuring the natural frequency of the resonator.

[0016] In addition, the present invention provides a press-fit resonator, a filter including the same, and a method for manufacturing the filter, which can reduce the size of the resonant disk panel reflectively compared to a conventional one by simply forming a minimum gas discharge hole at the center of the resonant disk panel for the discharge of gas generated during welding, thereby making the volume of the entire product compact.

[0017] In addition, another object of the present invention is to provide a press-fit resonator, a filter including the same, and a method for manufacturing the filter, which can minimize the insertion length of a short pin used in measuring the natural frequency of a resonator within a cavity, thereby minimizing the error range and thereby stabilizing quality.

[0018] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

[0019]

[0020] A press-fit resonator according to one embodiment of the present invention comprises a resonator body having an empty interior and fixed to a bottom surface within a cavity of a filter body having one side opened, and a resonant disk panel having a gas exhaust hole formed therein and communicating with the interior of the resonator body and fixed to an upper end of the resonator body, wherein a lower press-fit portion is integrally provided at a lower end of the resonator body, in which at least one tension slit is formed so that a predetermined tension is applied toward the inner circumferential surface of the resonator installation boss formed on the bottom surface of the cavity when the resonator installation boss is press-fitted to the inner circumferential surface of the resonator installation boss.

[0021] Here, the lower press-in portion can be formed to be separated from the resonant rod body.

[0022] In addition, the lower press-in portion and the resonant rod body are separated by a step line, and the outer diameter of the lower press-in portion can be formed to be smaller than the outer diameter of the resonant rod body.

[0023] Additionally, the outer diameter of the lower press-fit portion may be formed to gradually decrease from the step line to the lower end.

[0024] In addition, the at least one tension slit formed in the lower press-fit portion may be formed in a shape in which a predetermined length is cut in the longitudinal direction of the resonant rod body from the lower end.

[0025] Additionally, the at least one tension slit may be formed to be cut from the step line to the bottom.

[0026] Additionally, the at least one tension slit may be formed in a plurality of positions spaced apart from each other in the circumferential direction of the lower press-fit portion.

[0027] In addition, the resonant rod body may be cylindrical, and the resonant disk panel may be provided in the form of a circular panel.

[0028] In addition, the inner diameter of the gas discharge hole formed in the resonant disk panel may be formed to be smaller than the outer diameter of a short pin inserted into the cavity when measuring the natural frequency of an adjacent resonator.

[0029] In addition, the upper portion of the resonant rod body may be integrally formed with an upper joint portion having a tapered cross-section in which the outer diameter gradually decreases toward the upper portion where it contacts the resonant disk panel.

[0030] Additionally, the upper joint and the lower surface of the resonant disk panel can be joined by a soldering-type welding joint.

[0031] In addition, the upper joint may be formed to have a tapered cross-sectional thickness that retains an amount of heat sufficient to prevent the resonant disk panel from being deformed by the welding heat provided when welding the contact surface of the resonant disk panel.

[0032] Additionally, the inner diameter of the upper joint may be the same as the inner diameter of the resonant rod body.

[0033] Additionally, the upper joint can be formed so that the outer diameter gradually decreases without a step up to the upper end.

[0034] According to one embodiment of the present invention, a filter includes a filter body having a cavity formed inside with an open upper portion and a resonant rod installation boss formed to protrude upward on a bottom surface of the cavity, a press-fit resonator fixed to the cavity of the filter body and having a lower portion press-fitted and fixed to an inner surface of the resonant rod installation boss, and a filter tuning cover provided to cover the opened upper portion of the filter body, wherein the press-fit resonator includes a resonant rod body having an empty interior and a resonant disk panel fixed to an upper portion of the resonant rod body and having a gas exhaust hole formed therein that communicates with the interior of the resonant rod body, and a lower press-fit portion integrally formed with at least one tension slit at a lower portion of the resonant rod body so that a predetermined tension is applied toward the inner surface of the resonant rod installation boss formed on the bottom surface of the cavity when the resonant rod is press-fitted against the inner surface of the resonant rod installation boss.

[0035] Here, the lower press-in portion is formed to be stepped and separated from the resonant rod body by a step line, and the outer diameter of the lower press-in portion may be formed to be smaller than the outer diameter of the resonant rod body so that the resonant rod body is hung on the upper end of the resonant rod installation boss at the step line.

[0036] In addition, the at least one tension slit formed in the lower press-fit portion is formed by cutting a predetermined length in the longitudinal direction of the resonant rod body from the lower end, and a plurality of tension slits are formed to be spaced apart from each other in the circumferential direction of the lower press-fit portion, and the outer surface of the lower press-fit portion between the tension slits can have a tension force in a form in which it is in close contact with the inner surface of the resonant rod installation boss.

[0037] In addition, the resonant rod body is cylindrical, the resonant disk panel is provided in the form of a circular panel, and the gas discharge hole formed in the resonant disk panel can be formed directly below the screw fixing hole formed in the filter tuning cover.

[0038] A method for manufacturing a filter according to one embodiment of the present invention includes a filter body preparation step of preparing a filter body having a plurality of resonator mounting bosses formed on the bottom surface of each of a plurality of cavities having one side opened, a resonator fixing step of press-fitting and installing a press-fit resonator into the inside of the resonator mounting bosses, a solder cream applying step of applying solder cream along the upper end of the resonator mounting boss and the upper end of the opened one side of the filter body, and a solder fixing step of placing a filter tuning cover on the opened one side of the filter body and then putting the filter body into an oven to simultaneously solder the press-fit resonator and the filter tuning cover.

[0039] Here, before the solder fixing step, a vacuuming step for vacuuming the cavity of the filter body may be further included.

[0040] In addition, before the resonator fixing step, a step of preparing the press-fit resonator may further include a resonator manufacturing step of manufacturing the resonator integrally by welding a resonant disk panel to the upper end of the resonator rod body.

[0041] In addition, the resonator manufacturing step may include a process of forming an upper joint portion welded to the resonant disk panel at the upper end of the resonant rod body, and a lower press-fit portion press-fitted to the resonant rod installation boss at the lower end of the resonant rod body.

[0042] In addition, after the solder fixing step, the method further includes a natural frequency measuring step of measuring the natural frequency of an adjacent resonator, and the resonator manufacturing step includes a step of forming a gas exhaust hole in the resonant disk panel that communicates with the inside of the resonant rod body, wherein the gas exhaust hole can be formed to have a smaller outer diameter than a short pin inserted into the cavity in the natural frequency measuring step.

[0043] In addition, the above-described natural frequency measurement step may be a step performed after covering and short-circuiting the gas discharge hole formed in the resonance disk panel of the resonator adjacent to the resonator whose natural frequency is to be measured using the short pin.

[0044]

[0045] According to an embodiment of the present invention, a press-type resonator and a filter including the same can achieve the following various effects.

[0046] First, it has the effect of minimizing the angle tuning process that will be performed later by reducing the error in measuring the natural frequency of the resonator.

[0047] Second, the resonator is simply fixed to the resonator mounting boss by force-fitting (or press-fitting) using the lower press-fit portion, and then the filter tuning cover and the filter body are soldered together at the same time, which has the effect of making manufacturing and assembly easy.

[0048] Third, since the short pin does not need to pass through the center of the resonant disk panel when measuring the natural frequency of the resonator, the reduced area of ​​the resonant disk panel is minimized, thereby securing the maximum capacitance capacity and thus securing a high Q value compared to the same volume.

[0049] Fourth, the size of the resonant disk panel can be reduced compared to conventional ones, which has the effect of making the volume of the entire product compact.

[0050] Fifth, it has the effect of minimizing the error range and stabilizing quality by minimizing the insertion length of the short pin used in measuring the natural frequency of the resonator within the cavity.

[0051]

[0052] Figure 1 is a cross-sectional view showing the installation of a resonator rod according to the prior art and the measurement of the resonator rod frequency using a short pin.

[0053] FIG. 2 is a perspective view of an external appearance of a press-fit resonator and a filter including the same according to one embodiment of the present invention.

[0054] Figures 3a and 3b are exploded perspective views of the filter tuning cover of the configuration of Figure 2,

[0055] Figure 4 is a cutaway perspective view of Figure 2,

[0056] FIG. 5 is a cross-sectional view showing the installation inside the filter of a press-fit resonator according to one embodiment of the present invention and the frequency measurement using a short pin.

[0057] FIG. 6a and FIG. 6b are downward perspective views and upward perspective views showing a press-fit resonator according to one embodiment of the present invention,

[0058] Figures 7a and 7b are exploded perspective views of Figures 6a and 6b,

[0059] Fig. 8 is a cross-sectional view of a press-fit resonator according to one embodiment of the present invention;

[0060] Fig. 9 is a cross-sectional view showing the joint appearance of the resonance rod installation boss of the press-fit resonator according to one embodiment of the present invention.

[0061] Figure 10 is a partially enlarged view of the “a” and “b” parts of Figure 9,

[0062] Figures 11a and 11b are actual product photos of parts “a” and “b” of Figure 9, respectively.

[0063] Figure 12 is a block diagram showing a method for manufacturing a filter according to one embodiment of the present invention.

[0064] Figure 13 is a table showing the simulation results and actual product test results compared to customer requirements by Tx band.

[0065] Figures 14a and 14b are graphs showing the simulation results based on the Tx and Rx sections and the frequency characteristics of the actual product.

[0066] Figure 15a is a graph showing the Tx and Rx section frequency characteristics when the actual product application area is 25℃.

[0067] Figure 15b is a graph showing the Tx and Rx section frequency characteristics when the actual product application area is 90℃.

[0068] Figure 15c is a graph showing a frequency characteristic that overlaps the results of Figures 15a and 15b.

[0069]

[0070] <Explanation of symbols>

[0071] 100: Filter 110: Filter housing

[0072] 120: Filter body 125: Resonator rod installation boss

[0073] 125a: Solder application step 130: Filter tuning cover

[0074] 131: Engraving part 135: Screw installation hole

[0075] 140: Press-fit resonator 141: Resonator body

[0076] 142: Lower press-in part 142-1: Step line

[0077] 142a: Tension slit 143: Top joint

[0078] 144: Solder cream 145: Resonant disk panel

[0079] 146: Solder joint area

[0080]

[0081] Hereinafter, a press-fit resonator according to one embodiment of the present invention, a filter including the same, and a method for manufacturing the filter will be described in detail with reference to the attached drawings.

[0082] When assigning reference numerals to components in each drawing, it should be noted that identical components are assigned the same numerals whenever possible, even if they appear on different drawings. Furthermore, when describing embodiments of the present invention, if a detailed description of a related known configuration or function is deemed to hinder understanding of the embodiments of the present invention, the detailed description will be omitted.

[0083] When describing components of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only intended to distinguish the components from other components, and do not limit the nature, order, or sequence of the components. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined in this application.

[0084]

[0085] FIG. 2 is a perspective view of an external appearance of a press-type resonator and a filter including the same according to one embodiment of the present invention, FIGS. 3a and 3b are exploded perspective views of the filter tuning cover of FIG. 2, which is separated, FIG. 4 is a cut-away perspective view of FIG. 2, and FIG. 5 is a cross-sectional view showing an installation state of the press-type resonator according to one embodiment of the present invention inside a filter and a frequency measurement state using a short pin.

[0086] A filter (100) to which a pressure-type resonator (140) according to one embodiment of the present invention is applied may include a filter housing (110) composed of a filter body (120) having one side open and a cavity (C) having a predetermined space formed therein, and a filter tuning cover (130) coupled to shield the opened side of the filter body (120), as shown in FIGS. 2 to 5.

[0087] The filter body (120), as shown in FIG. 2, is formed in a rectangular parallelepiped shape that is approximately elongated in the longitudinal direction, and the above-described cavity (C) may be provided on one side and the other side in the thickness direction centered on the center.

[0088] Hereinafter, a cavity provided on one side in the thickness direction of the filter body (120) is referred to as a one-side cavity (C1), and a cavity provided on the other side in the thickness direction of the filter body (120) is referred to as a other-side cavity (C2).

[0089] Here, a filter (100) according to one embodiment of the present invention may be formed as a dual band filter of a first frequency filter unit (100A) that performs filtering within a first frequency band range through a one-sided cavity (C1) and a second frequency filter unit (100B) that performs filtering within a second frequency band range through a other-sided cavity (C2).

[0090] A filter (100) according to one embodiment of the present invention may include a signal input unit (105A) provided on one widthwise side of a filter body (120) and inputting a predetermined electrical signal to the first frequency filter unit (100A) side and the second frequency filter unit (100B) side described above, and a signal output unit (105B) provided on the other widthwise side of the filter body (120) and outputting a predetermined electrical signal from the first frequency filter unit (100A) side and the second frequency filter unit (100B) side, respectively.

[0091] Here, the signal input section (105A) and the signal output section (105B), despite their names, can have roles that are interchangeable depending on the direction of flow of the electrical signal.

[0092] For example, when the filter (100) according to one embodiment of the present invention functions in a transmission (Tx) mode, the signal input unit (105A), as the name of the component, serves as a medium for inputting an electrical signal into one cavity (C1) and the other cavity (C2) of the filter body (120) through a main board (not shown), and at this time, the signal output unit (105B) serves as a medium for outputting an electrical signal filtered by the first frequency filter unit (100A) and the second frequency filter unit (100B) to an antenna element unit (not shown).

[0093] On the other hand, when the filter (100) according to one embodiment of the present invention functions in a receive (Rx) mode, it can be understood that it performs a role opposite to that described above.

[0094] Meanwhile, the first frequency filter unit (100A) and the second frequency filter unit (100B) may be provided so that filtering of different frequency bandwidths is performed separately. For example, the first frequency filter unit (100A) may be involved in a frequency band covering a Low Band band that radiates a frequency defined between 600 MHz and 800 MHz, and the second frequency filter unit (100B) may be involved in a frequency band covering a Middle Band band that radiates a frequency defined between 1.7 GHz and 2.4 GHz.

[0095] In particular, the first frequency filter unit (100A) and the second frequency filter unit (100B) can each be implemented as a Dual Filter.

[0096] This will be described in more detail with reference to FIGS. 3A and 3B. One side cavity (C, C1) of the first frequency filter unit (100A) is partitioned into a plurality of spaces by a plurality of partition walls (127) and windows (128) formed thereby, and a press-fit resonator (140) according to one embodiment of the present invention can be installed one by one in each of the partitioned spaces.

[0097] Here, a common resonator (not indicated in the drawing) may be provided in the center of one side cavity (C, C1), and a press-fit resonator (140) of the corresponding frequency band may be arranged in the cavity (C) on the left and the cavity (C) on the right based on the common resonator.

[0098] Meanwhile, with the center of the filter body (120) as the standard, one side cavity (C1) and the other side cavity (C2) provided on one side and the other side in the thickness direction, respectively, are formed to be open to one side and the other side in the thickness direction, as shown in FIG. 4, and a resonance rod installation boss (125) on which a press-fit resonator (140), which will be described later, is installed and fixed on the side of the partition (not indicated in the drawing symbol) that partitions both cavities (C1, C2) in the thickness direction can be formed to protrude toward each of the opened sides. This will be described in more detail later.

[0099] The filter tuning cover (130) is formed to correspond to the position where each of the above-described press-type resonators (140) is installed, and a plurality of stamping portions (131) are provided in a circular shape so that a portion of the thickness of the filter tuning cover (130) is deleted (removed), and a screw installation hole (135) into which a tuning screw (not shown) is fastened can be formed in the center portion of the plurality of stamping portions (131) so as to be in communication with the cavity (C).

[0100] According to one embodiment of the present invention, a filter (100) having such a configuration, as shown in FIG. 5, after a plurality of press-fit resonators (140) are press-fitted and fixed to resonator rod installation bosses (125) formed on the bottom surface of a cavity (C), a soldering material (144) is applied along the periphery of the tip (upper) of the resonator rod installation boss (125), and at the same time, a soldering material (134) is applied along the upper edge of the filter body (120), and then a filter tuning cover (130) covering one open side of the cavity (C) is solder-joined.

[0101] Here, when measuring the natural frequency of one of the press-fit resonators (140) (meaning the press-fit resonator (140) in the middle of the resonators in FIG. 4), the adjacent press-fit resonators (140) (meaning the press-fit resonators (140) on the left and right of the resonators in FIG. 4) excluding the press-fit resonator (140) in question must be maintained in a short-circuited state. That is, the short pins (50A, 50B) are inserted through the screw installation holes (135) of the filter tuning covers (130) formed directly above the left and right press-fit resonators (140), so that the lower ends of the short pins (50A, 50B) contact the press-fit resonators (140) made of metal, thereby short-circuiting, thereby allowing the natural frequency of the press-fit resonator (140) in the middle to be measured.

[0102] In the filter (100) according to one embodiment of the present invention, the press-fit resonator (140) is installed by press-fitting without a separate fixing screw on the resonant rod installation boss (125) formed on the bottom surface of the filter body (120), so that there is no need to form an excessively large center hole (not shown) for installing the fixing screw in the resonant disk panel (145) described later. Accordingly, the length of the short pin (50A, 50B) inserted for shorting the adjacent press-fit resonator (140) can also be designed to be shorter than in the case of the fixing type using a fixing screw. The reduction in the insertion length of the short pin (50A, 50B) into the cavity (C) leads to the advantage of minimizing the error range during frequency measurement. When the error range during frequency measurement is minimized, the shape deformation range due to the stamping of the stamping portion (131) formed on the filter tuning cover (140) during frequency tuning can also be minimized.

[0103] Hereinafter, a press-type resonator (140) according to one embodiment of the present invention capable of achieving various effects as described above will be described in detail.

[0104] FIGS. 6A and 6B are downward perspective views and upward perspective views showing a press-fit resonator according to an embodiment of the present invention, FIGS. 7A and 7B are exploded perspective views of FIGS. 6A and 6B, FIG. 8 is a cross-sectional view of a press-fit resonator according to an embodiment of the present invention, FIG. 9 is a cross-sectional view showing a coupling state of a resonator rod installation boss of a press-fit resonator according to an embodiment of the present invention, FIG. 10 is a partial enlarged view of portions “A” and “B” of FIG. 9, and FIGS. 11A and 11B are actual product photographs of portions “A” and “B” of FIG. 9, respectively.

[0105] A press-fit resonator (140) according to one embodiment of the present invention may include, as referenced in FIGS. 6A to 11B, a resonant rod body (141) that is fixed to the bottom surface within the cavity (C) of the aforementioned filter body (120) having one side open and having an empty interior, and a resonant disk panel (145) that is fixed to the upper end of the resonant rod body (141) and has a gas discharge hole (145h) formed therein that communicates with the interior of the resonant rod body (141).

[0106] Here, the lower end of the resonance rod body (141) may be integrally provided with a lower press-fit portion (142) having at least one tension slit (142a) formed therein so that a predetermined tension is applied toward the inner surface (i.e., in the radial direction) of the resonance rod installation boss (125) formed on the bottom surface of the cavity (C) when the resonance rod installation boss (125) is press-fitted to the inner surface.

[0107] The resonance rod installation boss (125) can be formed integrally on the bottom surface of the cavity (C) of the filter body (120), or can be manufactured separately and combined with the bottom surface of the cavity (C).

[0108] Such a resonance rod installation boss (125) may be provided in the form of a hollow pipe with an empty interior so that the lower press-fit portion (142) of the resonance rod body (141) described above moves downward and is forcibly fitted.

[0109] Here, on the inner side of the upper edge of the resonance rod installation boss (125), a solder application step (125a) may be formed with a portion of the inner circumference cut off, where solder cream (144) applied for solder bonding with the resonance rod body (141) is settled and retained.

[0110] Meanwhile, the lower press-fit portion (142) may be formed to be stepped and separated from the resonator body (141) by a step line (142-1). The step line (142-1) serves to prevent excessive insertion of the resonator body (141) by contacting the upper end of the resonator installation boss (125) when the resonator body (141) is forcibly fitted (press-fitted) into the resonator installation boss (125). To this end, the outer diameter of the lower press-fit portion (142) may be formed to be smaller than the outer diameter of the resonator body (141). In addition, it is preferable that the outer diameter of the lower press-fit portion (142) be formed to gradually decrease from the step line (142-1) to the lower end so as to facilitate insertion and press-fitting of the lower press-fit portion (142) into the resonator installation boss (125).

[0111] In addition, the above-described at least one tension slit (142a) formed in the lower press-in portion (142) may be formed in a form in which a predetermined length is cut from the lower end in the longitudinal direction of the resonant rod body (141). At this time, the at least one tension slit (142a) may be formed to be cut from the step line (142-1) to the lower end.

[0112] In particular, at least one tension slit (142a) can be formed in a number of places spaced apart in the circumferential direction of the lower press-fit portion (142).

[0113] When the plurality of tension slits (142a) formed in this way are forcibly fitted through the upper part of the resonant rod installation boss (125) formed on the bottom surface of the cavity (C) through the lower press-in part (142) of the resonant rod body (141), the outer surface of the lower press-in part (142) between the tension slits (142a) is in close contact with the radial direction (i.e., the inner surface side) of the resonant rod installation boss (125) to have a predetermined tension force, and since the predetermined tension force is continuously applied to the inner surface of the resonant rod installation boss (125), stable temporary fixation to the resonant rod installation boss (125) can be achieved even before solder fixation using the solder cream (144) described later.

[0114] Meanwhile, as referenced in FIGS. 6A to 8, the resonant rod body (141) is a hollow cylindrical shape, and the resonant disk panel (145) is provided in the shape of a circular panel, and can be coupled orthogonally to the upper end of the resonant rod body (141).

[0115] More specifically, the resonance rod body (141) may be provided in the shape of a pipe with an empty cavity (140S) formed therein, and a portion of the lower part may be provided as the lower press-in portion (142) described above, and a portion of the upper part may be integrally formed with the upper joint portion (143) described later.

[0116] The resonant disk panel (145) can be integrally joined to the upper surface of the resonant rod body (141) through a welding joint including a soldering joint method. Generally, the resonant rod body (141) can be first welded to the resonant disk panel (145) before being press-fitted to the resonant rod installation boss (125).

[0117] At the upper part of the resonance rod body (141), an upper joint (143) that performs the function of minimizing the amount of heat retained from a welding tool (welder) not shown when welding with the above-described resonance disk panel (145) can be integrally formed.

[0118] More specifically, the upper joint (143) can be formed to have a tapered cross-section in which the outer diameter gradually decreases toward the upper part that contacts the lower surface of the resonant disk panel (145).

[0119] However, the inner diameter of the upper joint (143) here can be formed to be the same as the inner diameter of the resonant rod body (141).

[0120] Accordingly, the volume of the upper joint (143) in comparison to the same length from top to bottom is actually provided to be smaller than the volume of the resonant rod body (141), so that the welding heat of the welding tool transmitted from the welding tool to the resonant disk panel (145) can be minimized, and damage to the resonant disk panel (145) due to heat can be prevented, providing an advantage.

[0121] That is, the upper joint (143) can be formed to have the tapered cross-sectional thickness that retains an amount of heat sufficient to prevent the resonant disk panel (145) from being deformed by the welding heat provided when welding the contact surface of the resonant disk panel (145).

[0122] Unlike the lower press-fit portion (142) described above, the upper joint (143) can be formed so that the outer diameter gradually decreases without a step from the upper outer diameter of the resonant rod body (141).

[0123] Meanwhile, a gas discharge hole (145h) may be formed in the resonance disk panel (145) to discharge welding gas generated toward the inner hollow (140S) side when welding with the resonance rod body (141) to the outside.

[0124] The gas discharge hole (145h) corresponds to the central hole of the resonance disk panel (42) of the filter (1) according to the prior art illustrated in FIG. 1, and not only serves as an exhaust passage for the welding gas described above, but can also serve as a reference hole for a fixing jig (not shown) during welding. To this end, the gas discharge hole (145h) formed in the resonance disk panel (145) is preferably positioned so as to be formed directly below the screw fixing hole (135) formed in the filter tuning cover (130).

[0125] However, in the press-fit resonator (140) according to one embodiment of the present invention, unlike in the case of the prior art, the gas discharge hole (145h) formed in the resonant disk panel (145) is sufficient to be in contact with the resonant disk panel (145) made of a metal material without the need for the short pins (50A, 50B) to be inserted into the internal hollow (140S) of the resonant rod body (141), so it has the advantage of not needing to be formed larger than the diameter of the short pins (50A, 50B) or the inner diameter of the screw installation hole (135) of the filter tuning cover (130) described later.

[0126] The fact that the resonant disk panel (145) can be manufactured by minimizing the size of the gas discharge hole (145h) means that the size of the resonant disk panel (145) itself can be reduced, which in turn can lead to the advantage of being able to manufacture the entire filter (1) product in a compact form.

[0127] In addition, as the size of the gas discharge hole (145h) of the resonant disk panel (145) is reduced, a sufficient capacitance capacity formed between the inner surface of the filter tuning cover (130) can be secured, thereby enabling the implementation of a high Q value for the same volume, which also leads to the advantage of being able to promote quality stabilization through a measurement inspection method of the natural frequency of the press-fit resonator (140) described later.

[0128] According to one embodiment of the present invention, a press-fit resonator (140) having such a configuration can be soldered in an SMT manner using solder cream (144) applied in the direction of the edge to the solder application step (125a) of the resonator installation boss (125) in the cavity (C) of the filter body (120) after being press-fitted, as shown in FIG. 5.

[0129] When solder cream (144) is applied in the direction of the edge along the solder application step (125a) formed along the upper end of the resonance rod installation boss (125), and then the inside of the cabinet (C) of the filter body (120) is vacuumed, and then exposed to a high or low temperature atmosphere such as the inside of an oven, the solder cream (144) melts and seeps into the space between the inner surface of the resonance rod installation boss (125) and the resonance rod body (141) (more specifically, the outer surface of the lower press-fit portion (142)) and hardens, thereby more stably fixing the resonance rod body (141) to the resonance rod installation boss (125).

[0130] Meanwhile, a filter (100) including a press-fit resonator (140) according to one embodiment of the present invention may further include a filter tuning cover (130) covering an opened side of the filter body (120).

[0131] On the outer surface of the filter tuning cover (130), as referenced in FIGS. 2 to 5, a tapping portion (131) can be formed with a relatively thin thickness to enable fine frequency tuning by adjusting the distance from the resonant disk panel (145) in the cavity (C) in a tapping manner.

[0132] In addition, in the filter tuning cover (130), as referenced in FIGS. 2 to 5, a screw installation hole (135) in which a tuning screw (not shown) is installed to enable individual frequency tuning at each position corresponding to a press-type resonator (140) according to an embodiment of the present invention installed in the cavity (C) may be formed in communication with the cavity (C).

[0133] The tuning screw installed through the screw installation hole (135) can be designed to tune the frequency by adjusting the distance between the lower part exposed to the cavity (C) side and the upper surface of the resonance disk panel (145) of the press-fit resonator (140) according to the striking method for the aforementioned striking part (131) or the rotation direction of the tuning screw itself.

[0134] Such a screw installation hole (135) is formed in the form of a hole in the center of the aforementioned angle portion (131), and before the tuning screw is installed, a short pin (50A, 50B) inserted to measure the natural frequency of a specific press-fit resonator (140) described later can be inserted through this hole to short-circuit it.

[0135] Meanwhile, if additional frequency adjustment is required after the frequency tuning is completed primarily using a tuning screw, the frequency tuning designer can perform a second frequency tuning by finely striking the striking part (131) using an unillustrated striking tool.

[0136] The filter tuning cover (130) configured as described above can be joined by soldering to cover the opened side of the filter body (120). To this end, solder cream (134) is applied along the upper edge of the filter body (120), and then the filter tuning cover (130) is placed therein and exposed to a high or low temperature atmosphere, such as the interior of an oven, for soldering.

[0137] In particular, the press-fit resonator (140) and the filter (100) including the same according to one embodiment of the present invention provide the advantage of ease of manufacturing and assembling the filter (100) by performing the same process of fixing the press-fit resonator (140) by a soldering method using solder cream (144) after press-fitting to the resonator installation boss (125) rather than a screw fastening method using a fixing screw, and by performing the same process of joining the filter tuning cover (130) to the filter body (120) by the same SMT fastening method using solder cream (134).

[0138] In addition, as referenced in FIG. 5 and FIG. 9, the press-fit resonator (140) and the filter (100) including the same according to one embodiment of the present invention can be used to measure the natural frequency of a specific press-fit resonator (140) by inserting the short pin (50A, 50B) through the screw fastening hole (135) of the filter tuning cover (130) to a length that only contacts the upper surface of the resonant disk panel (145), so that the size of the gas discharge hole (145h) formed in the resonant disk panel (145) can be minimized, and the error range when measuring the natural frequency can be minimized.

[0139] The manufacturing process and assembly process of the press-fit resonator (140) and the filter (100) including the same according to one embodiment of the present invention manufactured as described above are briefly described below with reference to FIGS. 9 to 11b.

[0140] According to one embodiment of the present invention, a press-fit resonator (140) and a filter (100) including the same are fixed by soldering (see reference numeral '146') a resonant rod body (141) and a resonant disk panel (145) through a soldering connection method via an upper joint (142), as shown in FIG. 10 (a) and FIG. 11b, and then, after plating the outer surface of the press-fit resonator (140), the press-fit resonator (140) is press-fitted to a resonant rod installation boss (125), and then, solder cream (144) is applied to a solder application step (125a) of the resonant rod installation boss (125).

[0141] At the same time, solder cream (134) is applied along the opened upper edge of the filter body (120) and then the filter tuning cover (130) is installed.

[0142] In this way, a plurality of press-fit resonators (140) are stably fixed to the resonator rod installation boss (125) by a press-fit method, and the filter tuning cover (130) is secured to the filter body (120), and soldering can be performed using an SMT bonding method using a vacuum heat treatment method. At this time, the temperature condition of the SMT bonding method can be in any atmosphere, either high or low temperature.

[0143] In particular, since the soldering joint is performed by heat treatment in a vacuum state in which the cavity (C) of the filter body (120) is evacuated, the solder cream (144) applied to the resonant rod installation boss (125) corresponding to the cavity (C) naturally melts and seeps between the outer surface of the lower joint (142) of the press-fit resonator (140) and the inner surface of the resonant rod installation boss (125), so that a more stable soldering joint can be achieved.

[0144] Figure 12 is a block diagram illustrating a method for manufacturing a filter according to one embodiment of the present invention.

[0145] A method for manufacturing a filter according to one embodiment of the present invention may include a filter body preparation step (S10), a resonator fixing step (S30), a solder cream application step (S40), a solder fixing step (S60), and a natural frequency measurement step (S70), as shown in FIG. 12.

[0146] The filter body preparation step (S10) can be defined as a step of preparing a filter body (120) in which a plurality of resonance rod installation bosses (125) are formed on the bottom surface of each of a plurality of cavities (C) with one side open.

[0147] Here, the resonator installation boss (125) can be formed as many times as the number of cavities (C) partitioned by a partition wall or window, etc., so that one resonator (140) is installed in each cavity (C), and can be formed integrally with the filter body (120) or manufactured separately from the filter body (120) and then combined with the bottom surface of the cavity (C).

[0148] Meanwhile, the resonator fixing step (S30) can be defined as a step of press-fitting and installing the press-fit resonator (140) according to the above-described embodiment of the present invention into the inside of the resonator rod installation boss (125). The resonator fixing step (S30) can be understood as a step of temporarily fixing the press-fit resonator (140) to the resonator rod installation boss (125).

[0149] Here, the method for manufacturing a filter according to one embodiment of the present invention may further include a resonator manufacturing step (S20) of manufacturing a resonator integrally by welding a resonator disk panel (145) to the upper end of a resonator rod body (141), as a step of preparing a press-fit resonator (140) before the resonator fixing step (S30).

[0150] The resonator manufacturing step (S20) may include a process (S21) of forming an upper joint (143) welded to a resonant disk panel (145) at the upper end of the resonant rod body (141), and a process (S22) of forming a lower press-fit portion (142) press-fitted to a resonant rod installation boss (125) at the lower end of the resonant rod body (141).

[0151] At this time, the upper joint (143) is preferably manufactured so that the outer diameter gradually decreases toward the upper side, but the inner diameter is formed to be the same as that of the resonant rod body (141), so as to minimize the influence of the welding heat on the resonant disk panel (145), as described above, and the lower press-fit portion (142) is preferably manufactured so that at least one tension slot (142a) is formed to add tension to the inner surface of the resonant rod installation boss (125), and the outer diameter gradually decreases toward the lower side.

[0152] In addition, the resonator manufacturing step (S20) may further include a step (S23) of forming a gas discharge hole (145h) in the resonant disk panel (145) that communicates with the inside of the resonant rod body (141). Here, the size of the gas discharge hole (145h) is sufficient to discharge gas, etc. generated when welding the resonant disk panel (145) to the upper end of the resonant rod body (141). However, in the natural frequency measuring step (S70) described later, the lower end of the short pin (50A, 50B) inserted into the cavity (C) may be formed to a size that allows the press-fit resonator (140) to short-circuit by covering and contacting the gas discharge hole (145h). Therefore, it is preferable that the gas discharge hole (145h) be formed to be smaller than the outer diameter of the short pin (50A, 50B) inserted into the cavity (C) in the natural frequency measurement step (S70).

[0153] Meanwhile, the solder fixing step (S60) may be a step of simultaneously soldering the press-fit resonator (140) and the filter tuning cover (130) by placing the filter tuning cover (130) on the opened side of the filter body (120) and then placing the filter body (120) into an oven (not shown).

[0154] Here, the method for manufacturing a filter according to one embodiment of the present invention may further include a solder cream application step (S40) of applying solder cream (134, 144) along the upper end of the resonator rod installation boss (125) and the upper end of one open side of the filter body (120) before the solder fixing step (S60). That is, the solder cream application step (S40) may be defined as a step of applying solder cream (134, 144) simultaneously so that the solder fixing of the press-fit resonator (140) to the resonator rod installation boss (125) and the solder fixing of the filter tuning cover (130) to the filter body (120) are performed as simultaneous processes rather than separate processes.

[0155] Meanwhile, a vacuuming step (S50) for vacuuming the cavity (C) of the filter body (120) before the solder fixing step (S60) or at least simultaneously with the solder fixing step (S60) may be further included. This is to ensure that, by vacuuming the cavity (C) of the filter body (120), the solder cream (144) applied at least to the upper portion of the resonator rod installation boss (125) naturally melts in a vacuum state during the heat treatment process in the oven and seeps between the inner surface of the resonator rod installation boss (125) and the outer surface of the press-fit resonator (140).

[0156] Finally, the method for manufacturing a filter according to one embodiment of the present invention may further include a natural frequency measuring step (S70), as referenced in FIG. 12. The natural frequency measuring step (S70) may be defined as a step performed after covering and short-circuiting a gas exhaust hole (145h) formed in a resonance disk panel (145) of a resonator (refer to the left and right resonators of the press-fit resonator (140) of FIG. 4) adjacent to a resonator whose natural frequency is to be measured (refer to the middle resonator of the press-fit resonator (140) of FIG. 4) using a short pin (50A, 50B).

[0157] Fig. 13 is a table showing the simulation results and the test results of the actual product compared to the customer's required specifications by Tx band, and Figs. 14a and 14b are graphs showing the simulation results and the frequency characteristics of the actual product based on the Rx (Fig. 14a) and Tx (Fig. 14b) sections, and Fig. 15a is a graph showing the frequency characteristics of the Tx and Rx sections when the actual product application area is 25℃, Fig. 15b is a graph showing the frequency characteristics of the Tx and Rx sections when the actual product application area is 90℃, and Fig. 15c is a graph showing the frequency characteristics by overlapping the result values ​​of Figs. 15a and 15b.

[0158] The characteristic test results of the press-fit resonator (140) and the filter (100) including the same according to one embodiment of the present invention configured as described above are secured at a level that satisfies all characteristic specifications, as shown in the result values ​​referenced in FIGS. 13 to 15, and thus have the advantage of being able to guarantee the quality of the product as well as unmanned automated assembly.

[0159] More specifically, the applicant of the present invention, after setting the customer's requirements for various characteristic items (Requirements) as referenced in (a) and (b) of FIG. 13, divided them into the case where the Tx Passband is 1930-1995 (a) and the case where the Tx Passband is 1850-1915 (b), derived each result value of the simulation through a program and the press-type resonator (140) according to the present invention and the filter (100) including the same (refer to 'This invention' item of FIG. 13).

[0160] Looking at the result values ​​referenced in Fig. 13, it can be seen that the customer's required specifications are well satisfied not only in the simulation but also in the actual product (This invention) related to the present invention across various characteristic items.

[0161] In particular, when comparing the room temperature characteristics of the Rx of Fig. 14a and the Tx of Fig. 14b with the simulation results and the actual product (This invention) results, it can be confirmed from the frequency characteristic graph that the relative signal sections are blocked on both the left and right sides of the Rx section and the Tx section.

[0162] In addition, referring to Figs. 15a to 15c, which are frequency characteristic graphs of Tx and Rx, it can be seen that the signal blocking results for each section at room temperatures of 25°C and 90°C, as requested by the customer, meet the customer's requirements. In particular, referring to the graph superimposed in Fig. 15c, it can be confirmed that the frequency characteristic changes at room temperatures of 25°C and 90°C are almost identical.

[0163] In this way, according to the press-fit resonator (140) and the filter (100) including the same according to one embodiment of the present invention, the soldering joint of the press-fit resonator (140) and the soldering joint of the filter tuning cover (130) are simultaneously performed through the SMT bonding method, which is a soldering joint method, so that not only can the natural frequency of a specific press-fit resonator (140) be easily measured, but also an additional advantage of a compact design of the product due to securing the capacitance capacity of the resonant disk panel (145) can be provided, and an advantage of enabling automated design and execution during frequency tuning is provided.

[0164]

[0165] Hereinafter, a press-fit resonator and a filter including the same according to an embodiment of the present invention have 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 embodiments, and it will be understood that various modifications and equivalent implementations are possible by those skilled in the art to which the present invention pertains. Therefore, the true scope of the present invention is defined by the claims set forth below.

Claims

1. A resonator body that is fixed to the bottom surface within the cavity of a filter body with one side open and is hollow inside; and A resonance disk panel is fixed to the upper end of the resonance rod body and has a gas discharge hole formed therein that communicates with the inside of the resonance rod body; A press-fit resonator, wherein the lower part of the resonator body is integrally provided with a lower press-fit portion having at least one tension slit formed therein so that a predetermined tension is applied toward the inner surface of the resonator installation boss formed on the bottom surface of the cavity when the resonator installation boss is press-fitted against the inner surface of the resonator installation boss.

2. In claim 1, A press-fit resonator, wherein the lower press-fit portion is formed to be separated from the resonator body by a step.

3. In claim 2, The above lower press-fit portion and the above resonant rod body are separated by a step line, A press-fit resonator, wherein the outer diameter of the lower press-fit portion is formed smaller than the outer diameter of the resonator body.

4. In claim 3, A press-fit resonator in which the outer diameter of the lower press-fit portion is formed to gradually decrease from the step line to the bottom.

5. In claim 3, A pressure-type resonator, wherein at least one tension slit formed in the lower press-in portion is formed in a shape in which a predetermined length is cut in the longitudinal direction of the resonator body from the lower end.

6. In claim 5, A press-fit resonator, wherein at least one tension slit is formed to be cut from the step line to the bottom.

7. In claim 5, A press-fit resonator, wherein at least one tension slit is formed in a plurality of positions spaced apart from each other in the circumferential direction of the lower press-fit portion.

8. In claim 1, A press-fit resonator in which the resonant rod body is cylindrical and the resonant disk panel is provided in the form of a circular panel.

9. In claim 1, A press-fit resonator, wherein the inner diameter of the gas discharge hole formed in the resonant disk panel is formed to be smaller than the outer diameter of the short pin inserted into the cavity when measuring the natural frequency of an adjacent resonator.

10. In claim 1, A press-fit resonator in which the upper joint is integrally formed at the upper end of the resonant rod body so as to have a tapered cross-section in which the outer diameter gradually decreases toward the upper end where it contacts the resonant disk panel.

11. In claim 10, A press-fit resonator in which the upper joint and the lower surface of the resonant disk panel are joined by a soldering-type welding joint.

12. In claim 11, A press-fit resonator, wherein the upper joint is formed to have a tapered cross-sectional thickness that retains an amount of heat sufficient to prevent the resonant disk panel from being deformed by welding heat provided when welding the contact surface of the resonant disk panel.

13. In claim 10, A press-fit resonator, wherein the inner diameter of the upper joint is the same as the inner diameter of the resonator body.

14. In claim 10, The above upper joint is a press-fit resonator formed so that the outer diameter gradually decreases without a step up to the top.

15. A filter body having a cavity with an open upper portion formed inside and a resonance rod installation boss formed to protrude upward on the bottom surface of the cavity; A press-fit resonator fixed to the cavity of the above filter body, the lower part of which is press-fitted and fixed to the inner surface of the resonance rod installation boss; and A filter tuning cover provided to cover the opened upper portion of the filter body; The above press-fit resonator is, A hollow resonator body; and A resonance disk panel is fixed to the upper end of the resonance rod body and has a gas discharge hole formed therein that communicates with the inside of the resonance rod body; A filter, wherein the lower part of the resonant rod body is integrally provided with a lower press-fit portion having at least one tension slit formed therein so that a predetermined tension is applied toward the inner surface of the resonant rod installation boss formed on the bottom surface of the cavity when the resonant rod installation boss is press-fitted against the inner surface of the resonant rod installation boss.

16. In claim 15, The above lower press-fit portion is formed to be stepped and separated from the resonant rod body by a step line, A filter in which the outer diameter of the lower press-fit portion is formed smaller than the outer diameter of the resonant rod body so that the resonant rod body is hung on the upper end of the resonant rod installation boss at the step line.

17. In claim 15, The at least one tension slit formed in the lower press-fit portion is formed by cutting a predetermined length in the longitudinal direction of the hollow body from the lower end, and a plurality of tension slits are formed spaced apart in the circumferential direction of the lower press-fit portion. A filter having tension force in such a way that the outer surface of the lower press-fit portion between the tension slits is in close contact with the inner surface of the resonant rod installation boss.

18. In claim 15, The above resonant rod body is cylindrical, and the above resonant disk panel is provided in the form of a circular panel. The gas discharge hole formed in the resonance disk panel is formed directly below the screw fixing hole formed in the filter tuning cover.

19. A filter body preparation step in which a filter body having a plurality of resonance rod installation bosses formed on the bottom surface of each of a plurality of cavities with one side open is prepared; A resonator fixing step for press-fitting and installing a press-fit resonator into the inside of the above resonator installation boss; A solder cream application step of applying solder cream along the upper side of the resonance rod installation boss and the upper side of the opened side of the filter body; and A method for manufacturing a filter, comprising: a solder fixing step of simultaneously soldering the press-fit resonator and the filter tuning cover by placing the filter tuning cover on an opened side of the filter body and then placing the filter body in an oven; 20. In claim 19, A method for manufacturing a filter, further comprising a vacuuming step of vacuuming the cavity of the filter body before the solder fixing step.

21. In claim 19, A method for manufacturing a filter, further comprising a step of preparing the press-fit resonator before the resonator fixing step, wherein the step comprises a resonator manufacturing step of manufacturing the resonator integrally by welding a resonance disk panel to the upper end of the resonator rod body.

22. In claim 19, A method for manufacturing a filter, wherein the above resonator manufacturing step includes a process of forming an upper joint portion welded to the resonant disk panel at the upper portion of the resonant rod body, and a lower press-fit portion press-fitted to the resonant rod installation boss at the lower portion of the resonant rod body.

23. In claim 21, After the solder fixing step, further comprising a natural frequency measurement step of measuring the natural frequency of an adjacent resonator; A method for manufacturing a filter, wherein the above resonator manufacturing step includes a process of forming a gas discharge hole in the resonant disk panel that communicates with the interior of the resonant rod body, wherein the gas discharge hole is formed to be smaller than the outer diameter of a short pin inserted into the cavity in the natural frequency measuring step.

24. In claim 23, A method for manufacturing a filter, wherein the above-mentioned natural frequency measurement step is a step performed after covering and short-circuiting the gas discharge hole formed in the resonance disk panel of the resonator adjacent to the resonator whose natural frequency is to be measured using the short pin.

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