Ceramic waveguide filter

Abstract

Disclosed are ceramic waveguide filters. According to an embodiment of the present disclosure, a ceramic waveguide filter is provided, the filter including a plurality of resonator blocks of a ceramic dielectric, the filter including: an input end and an output end formed in a slot shape having a predetermined depth on an outer surface of the ceramic waveguide filter; a plurality of resonators formed in a slot shape having a predetermined depth on an outer surface of each of the plurality of resonator blocks; and at least one front end delay adjustment unit adjacent to at least one of the input end and the output end and formed in a slot shape having a predetermined depth on an outer surface of the ceramic waveguide filter.

Description

Technical Field

[0001] This disclosure relates to a ceramic waveguide filter. Background Technology

[0002] The contents described in this section are for background information only and do not constitute prior art.

[0003] Recently, with the increasing variety of wireless communication services, the frequency environment has become increasingly complex. Since frequency resources for wireless communication are limited, it is necessary to set wireless communication channels as close as possible to effectively utilize frequency resources.

[0004] In environments providing various wireless communication services, signal interference can occur. Therefore, to minimize signal interference between adjacent frequency resources, a bandpass filter for a specific frequency band is needed.

[0005] For frequency filters mounted on antennas, commissioning is required after the filter is manufactured. One of the first operations performed during commissioning is front-end delay verification. The input and output terminals have adjacent resonators and connecting cables. Depending on the cables formed on the input and output terminals and their positions, the resulting front-end delay values ​​will differ. Only when this front-end delay reaches the design value can the desired skit characteristics and filterable frequency bandwidth be obtained; therefore, front-end delay commissioning is crucial.

[0006] For air-filled cavity bandpass filters, the front-end delay can be easily adjusted using the shape and position of the rope or tuning screws; conversely, for ceramic waveguide filters formed of dielectrics, space or structure will be limited in order to adjust the front-end delay. Summary of the Invention

[0007] (a) Technical problems to be solved

[0008] Therefore, the main objective of this disclosure is to adjust the front-end delay that occurs at the input and output ends of a ceramic waveguide filter.

[0009] Furthermore, the main objective of this disclosure is to reduce spurious signals generated during signal filtering.

[0010] The technical problems of this invention are not limited to those described above. Those skilled in the art should be able to clearly understand other technical problems not mentioned herein through the following description.

[0011] (II) Technical Solution

[0012] According to one embodiment of the present disclosure, a ceramic waveguide filter is provided, the filter including a plurality of resonant blocks of ceramic dielectric, the filter including: an input end and an output end formed in a groove shape with a predetermined depth on the outer surface of the ceramic waveguide filter; a plurality of resonators formed in a groove shape with a predetermined depth on the outer surface of each of the plurality of resonant blocks; and at least one front-end delay adjustment unit adjacent to at least one of the input end and the output end, and formed in a groove shape with a predetermined depth on the outer surface of the ceramic waveguide filter.

[0013] Furthermore, the front-end delay adjustment unit can adjust the variation range of at least one of the input front-end delay and the output front-end delay by adjusting at least one of the slot depth and slot width formed on each front-end delay adjustment unit.

[0014] Furthermore, at least one front-end delay adjustment unit of the ceramic waveguide filter may be located on at least one of the upper or lower surfaces of the ceramic waveguide filter.

[0015] Furthermore, in at least a portion of the region between adjacent resonant blocks in a plurality of resonant blocks, at least one of the upper and lower surfaces of the ceramic waveguide filter may further include at least one slot having a predetermined depth.

[0016] Furthermore, a portion of at least one of the front-end delay adjustment units overlaps with the other slots in at least one slot to form a slot of a predetermined depth.

[0017] Furthermore, the at least one front-end delay adjustment unit arranged overlapping the slot may have a semi-circular cross-section.

[0018] Furthermore, the at least one front-end delay adjustment unit may have a cylindrical or N-prism shape (N is a natural number greater than 3).

[0019] (III) Beneficial Effects

[0020] As described above, according to this embodiment, the ceramic waveguide filter has the following effect: It has the effect of adjusting the front-end delay by arranging a front-end delay adjustment unit at a position adjacent to the input and output terminals, wherein the front-end delay adjustment unit is a groove having a predetermined depth extending from the outer surface of the ceramic waveguide filter.

[0021] In addition, it has the effect of reducing stray energy by forming slots between resonant blocks. Attached Figure Description

[0022] Figure 1 This is a projected perspective view of a ceramic waveguide filter according to an embodiment of the present disclosure.

[0023] Figure 2This is a top view of a ceramic waveguide filter according to an embodiment of the present disclosure.

[0024] Figure 3 This is a bottom view of a ceramic waveguide filter according to an embodiment of the present disclosure.

[0025] Figure 4 It is a graph used to illustrate the effect of front-end delay adjustment based on the front-end delay adjustment unit.

[0026] Figure 5 This is a projected perspective view of a ceramic waveguide filter according to another embodiment of the present disclosure.

[0027] Figure 6 It is a graph used to illustrate the spurious reduction effect based on slots. Detailed Implementation

[0028] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. When labeling the drawings, the same reference numerals are used as much as possible, even if the same components appear in different drawings. It should also be noted that throughout this specification, detailed descriptions of known components and functions are omitted if it is believed that such detailed descriptions would obscure the subject matter of the invention.

[0029] In describing the constituent elements of the embodiments of the present invention, terms such as first, second, i), ii), a), b), etc., may be used. These terms are merely for distinguishing the corresponding constituent element from other constituent elements and do not limit their nature, order, or sequence. Throughout the specification, if a constituent element "comprises" or "possesses" another constituent element, unless otherwise stated, it shall be understood that a constituent element further includes the other constituent element, rather than that a constituent element excludes the other constituent element.

[0030] Figure 1 This is a projected perspective view of a ceramic waveguide filter according to an embodiment of the present disclosure. Figure 2 This is a top view of a ceramic waveguide filter according to an embodiment of the present disclosure. Figure 3 This is a bottom view of a ceramic waveguide filter according to an embodiment of the present disclosure.

[0031] Reference Figures 1 to 3 The ceramic waveguide filter 100 includes all or part of an input terminal 131, an output terminal 132, resonant blocks 111 to 118, resonators 121 to 128, front-end delay adjustment units 141 and 142, and a tuning unit (not shown). Figure 1As shown, the ceramic waveguide filter 100 can be formed in a hexahedral shape, but is not limited to this; it can have various shapes depending on the number and connection shape of the resonators 121 to 128. The ceramic waveguide filter 100 is a single piece, with no step differences between the resonators 111 to 118 and a hexahedral shape, thereby simplifying the manufacturing process and improving production efficiency. The height H1 of the ceramic waveguide filter 100 can be 5.5 mm to 6.5 mm.

[0032] Input terminal 131 and output terminal 132 can be formed on one surface of the ceramic waveguide filter 100, and multiple resonators 121 to 128 can be formed on a different surface than input terminal 131 and output terminal 132. That is, input terminal 131 and output terminal 132 can be formed in the shape of a groove with a predetermined depth on the outer surface of the ceramic waveguide filter 100. Multiple resonators 121 to 128 can be formed in the shape of a groove with a predetermined depth on the outer surface of the ceramic waveguide filter 100, and each resonator can be distinguished by a barrier wall 150. Figure 1 As shown, the grooves forming the multiple resonators 121 to 128 can be cylindrical, but are not limited to this; they can also be formed in various other shapes besides cylindrical. The width W1 of the multiple resonators 121 to 128 can be 3.5 mm to 4.5 mm respectively.

[0033] Input terminal 131 and output terminal 132 are input / output ports used to input signals to the ceramic waveguide filter 100 and output signals that have passed through the ceramic waveguide filter 100. Input terminal 131 and output terminal 132 can be formed by a surface mount structure. Furthermore, input terminal 131 and output terminal 132 can be formed with slots. The slots of input terminal 131 and output terminal 132 can be arranged corresponding to the positions of the first resonator 121 or the eighth resonator 128 arranged on the reverse side of the ceramic waveguide filter 100. The slots of input terminal 131 and output terminal 132 can be smaller than the slots of the corresponding first resonator 121 or the eighth resonator 128. Connectors are inserted and connected into the slots of input terminal 131 and output terminal 132, enabling connection to signal lines used to form the connectors. The signal lines can be wound with Teflon.

[0034] The ceramic waveguide filter 100 may include multiple resonant blocks 111 to 118, each of which may have a resonator formed on it. Figure 1 In the middle, eight resonators 121 to 128 are formed on eight resonant blocks 111 to 118, but the number of resonant blocks 111 to 118 and resonators 121 to 128 is not limited by the above-mentioned number.

[0035] exist Figure 1In this configuration, the eight resonators 121 to 128 can be defined as the first resonator 121 to the eighth resonator 128, respectively. The first resonator 121 can be formed at a position on the other surface corresponding to the input terminal 131. That is, the slot of the first resonator 121 can be formed at a predetermined height on the opposite side of the input terminal 131.

[0036] Below, with Figure 1 The ceramic waveguide filter 100 shown is used as a reference for explanation. A second resonator 122 is formed extending in a first direction toward the first resonator 121, and a third resonator 123 is formed extending in a second direction toward the second resonator 122. A fourth resonator 124 is formed extending in a second direction toward the third resonator 123, and a fifth resonator 125 is formed extending in a second direction toward the fourth resonator 124. A sixth resonator 126 is formed extending in a second direction toward the fifth resonator 125, and a seventh resonator 127 is formed extending in a third direction toward the sixth resonator 126. An eighth resonator 128 is formed extending in a fourth direction toward the seventh resonator 127.

[0037] The eighth resonator 128 is formed on a surface opposite to the output terminal 132. That is, the slot of the eighth resonator 128 can be formed at a predetermined height on the opposite surface from the output terminal 132. Each resonator 121 to 128 can be separated by a barrier wall 150. The space enclosed by the barrier wall 150 can be formed by an internally hollow cavity 151.

[0038] The signal input at input terminal 131 passes sequentially from the first resonator 121 to the eighth resonator 128, and is filtered before being output from output terminal 132. That is, if a signal intended for filtering at the input terminal is input, the input signal resonates through the first resonator 121 of the first resonator block 111, and is then coupled through an open interval to the second resonator 122 of the adjacent second resonator block 112. Then, based on the coupling of each open interval, it is sequentially coupled to the third resonator 123 of the third resonator block 113, the fourth resonator 124 of the fourth resonator block 114, the fifth resonator 125 of the fifth resonator block 115, the sixth resonator of the sixth resonator block 116, the seventh resonator 127 of the seventh resonator block 117, and the eighth resonator 128 of the eighth resonator block 118, before being output as a filtered signal. The coupling structure between the resonators can be inductive or capacitive coupling.

[0039] Among them, the first direction and the second direction are perpendicular to each other, the third direction is perpendicular to the second direction and is the opposite direction of the first direction, and the fourth direction is perpendicular to the first direction and is the opposite direction of the second direction.

[0040] Figure 1The number and arrangement of the plurality of resonators 121 to 128 and the plurality of resonant blocks 111 to 118 shown are exemplary and are not limited thereto.

[0041] Front-end delay adjustment units 141 and 142 are adjacent to the input terminal 131 or the output terminal 132, and are formed in the form of slots with a predetermined depth on the outer surface of the ceramic waveguide filter 100. The slot depth H2 of the front-end delay adjustment units 141 and 142 can be from 0.5 mm to 1 mm. The slot width W2 of the front-end delay adjustment units 141 and 142 can be from 1.5 mm to 2 mm. More than one front-end delay adjustment unit 141 and 142 can be formed.

[0042] Front-end delay adjustment units 141 and 142 form recessed slots of predetermined length around input terminal 131 and output terminal 132, thereby adjusting the front-end delay of signals generated at input terminal 131 and output terminal 132. The front-end delay adjustment units 141 and 142 are arranged at a predetermined length interval from input terminal 131 or output terminal 132, and the front-end delay can vary depending on the length interval. Furthermore, the front-end delay is also affected by the position, slot height, and shape and size of the cross-sectional area of ​​the front-end delay adjustment units 141 and 142. That is, the front-end delay adjustment units 141 and 142 can adjust the variation range of the input front-end delay or output front-end delay according to the formed slot depth, respectively. Furthermore, the front-end delay adjustment units 141 and 142 can adjust the variation range of the input front-end delay or output front-end delay according to the formed slot width, respectively. For example, as... Figure 3 As shown, when the front-end delay adjustment units 141 and 142 are cylindrical, the variation range of the front-end delay can be adjusted by adjusting the groove width, i.e., the area of ​​the circular cross-section. When the front-end delay adjustment units 141 and 142 have a non-circular polygonal cross-section, the variation range of the front-end delay can be adjusted by adjusting the area of ​​the polygon.

[0043] Figure 4 It is a graph used to illustrate the effect of front-end delay adjustment based on the front-end delay adjustment unit. Figure 4 (a) is a graph showing the difference in input front-end delay based on the presence or absence of front-end delay adjustment units 141 and 142. Figure 4 (b) is a graph showing the difference in output front-end delay based on the presence or absence of front-end delay adjustment units 141 and 142.

[0044] Reference Figure 4 Figure (a) illustrates the curve A showing the input front-end delay when the ceramic waveguide filter 100 does not include the front-end delay adjustment units 141 and 142. i And when the ceramic waveguide filter 100 includes front-end delay adjustment units 141 and 142, the curve B showing the input front-end delay is displayed. iBased on a frequency of 2600MHz, an input front-end delay of 2.35ns is generated without front-end delay adjustment units 141 and 142, and an input front-end delay of 2.57ns is generated with front-end delay adjustment units 141 and 142. The difference in input front-end delay is 0.22ns depending on the presence or absence of front-end delay adjustment units 141 and 142.

[0045] Reference Figure 4 Figure (b) illustrates the curve A showing the output front-end delay when the ceramic waveguide filter 100 does not include the front-end delay adjustment units 141 and 142. o The figure also illustrates the curve B showing the output front-end delay when the ceramic waveguide filter 100 includes front-end delay adjustment units 141 and 142. o Based on a frequency of 2600MHz, an output front-end delay of 3.47ns is generated without front-end delay adjustment units 141 and 142, and an output front-end delay of 3.97ns is generated with front-end delay adjustment units 141 and 142. The difference in input front-end delay is 0.50ns depending on the presence or absence of front-end delay adjustment units 141 and 142.

[0046] exist Figures 1 to 3 In the design, front-end delay adjustment units 141 and 142 are arranged adjacent to the input terminal 131 and the output terminal 132 in a cylindrical shape, respectively. However, the front-end delay can also be adjusted by changing the arrangement, shape, and number of front-end delay adjustment units 141 and 142. That is, front-end delay adjustment units 141 and 142 can be formed in a cylindrical or N-prism shape (N is a natural number greater than 3), and can have a semi-circular cross-sectional area. In addition, front-end delay adjustment units 141 and 142 can also be formed in a shape in which the cross-sectional area of ​​the outer surface changes as it moves further away from the ceramic waveguide filter 100.

[0047] like Figure 4 As shown in the graph, the input front-end delay and the output front-end delay can be adjusted by arranging front-end delay adjustment units 141 and 142. Figure 4 The values ​​for the input front-end delay shown are merely illustrative and are not limited thereto.

[0048] Furthermore, the ceramic waveguide filter 100 may further include a tuning unit (not shown) corresponding to the shape of the front-end delay adjustment units 141 and 142. The tuning unit (not shown) is a component used to adjust the front-end delay after the ceramic waveguide filter 100 is manufactured. Depending on the number of front-end delay adjustment units 141 and 142 arranged, there may be one or more tuning units (not shown). The space between the front-end delay adjustment units 141 and 142 can be adjusted using the tuning unit (not shown), thereby adjusting the input front-end delay and the output front-end delay.

[0049] Figure 5 This is a projected perspective view of a ceramic waveguide filter according to another embodiment of the present disclosure.

[0050] Reference Figure 5 The ceramic waveguide filter may further include slots 161, 162, and 163. Slots 161, 162, and 163 may be formed at a predetermined depth in at least a portion of the region between adjacent resonant blocks and may be disposed on at least one of the upper and lower surfaces of the ceramic waveguide filter 100.

[0051] exist Figure 5 In this configuration, slots 161, 162, and 163 are arranged in the spaces between the first resonant block 111 and the second resonant block 112, between the first resonant block 111 and the eighth resonant block 118, between the fourth resonant block 114 and the fifth resonant block, and between the seventh resonant block 117 and the eighth resonant block 118. This is illustrative; slots 161, 162, and 163 can be arranged on the upper or lower surfaces between any adjacent resonant blocks.

[0052] exist Figure 5 In the diagram, based on the attached figure, the slots are formed only longitudinally, but they can also be formed laterally, such as between the second resonant block 112 and the third resonant block 113. Slots 161, 162, and 163 are not as shown... Figure 5 As shown, it must be a straight line shape, but it can also be a curved shape, etc. In addition, slots 161, 162 and 163 can also be right-angled or cross-shaped.

[0053] Furthermore, the shape of the recesses that form the slots 161, 162, and 163 is not limited. For example, the lower part of the slots 161, 162, and 163 can be flat or recessed.

[0054] When the ceramic waveguide filter 100 has multiple slots 161, 162 and 163, the slot depth or slot width of each slot 161, 162 and 163 can be different from each other.

[0055] When slots 161, 162, and 163 are arranged on the same surface with multiple front-end delay adjustment units 143 to 146, a portion of them may overlap. For example... Figure 5 As shown, the four front-end delay adjustment units 143 to 146 can overlap with slots 161, 162, and 163, and have a semi-circular cross-sectional shape. In this case, the shape of the cross-section and the degree of overlap of the four front-end delay adjustment units 143 to 146 are not limited.

[0056] This disclosure achieves the effect of reducing the degree of spurious components by further arranging at least one slot 161, 162 and 163 on the ceramic waveguide filter 100.

[0057] Figure 6 It is a graph used to illustrate the spurious reduction effect based on slots.

[0058] Figure 6 (a) is a graph showing the frequency components of the filter when no additional slots 161, 162, and 163 are arranged in the ceramic waveguide filter 100. Figure 6 (b) is a graph showing the frequency components of the filter when at least one slot 161, 162 and 163 are arranged in the ceramic waveguide filter 100.

[0059] exist Figure 6 (a) and Figure 6 In the graph shown in (b), comparing the X and Y regions of the spurious emission range confirms the difference in spurious emission reduction effect. Specifically, when comparing spurious emissions with frequency components from 5500MHz to 6100MHz, it is confirmed that the spurious emission is reduced to below approximately -9dB in the X region and to below approximately -15dB in the Y region. Therefore, the degree of spurious emission can be reduced simply by arranging slots 161, 162, and 163.

[0060] To remove spurious signals in the ceramic waveguide filter 100, a low-pass filter (LPF) can typically be added. However, this requires physical space and can lead to increased impedance matching or insertion loss. Furthermore, due to space constraints, it is more difficult to place an LPF in a ceramic waveguide filter. This disclosure eliminates the need for an additional LPF by forming slots of predetermined depth at the boundaries between the resonant blocks 111 to 118, thereby achieving a reduction in spurious signals.

[0061] The above description is merely illustrative of the technical concept of this embodiment. For those skilled in the art, various modifications and alterations can be made without departing from the essential characteristics of this embodiment. Therefore, this embodiment is for illustration and not for limiting the technical concept of this embodiment, and the scope of the technical concept of this embodiment is not limited by the above embodiments. The scope of protection of this embodiment should be interpreted based on the following claims, and all technical concepts within the equivalent scope thereof will be interpreted as falling within the scope of the rights of this embodiment.

[0062] [Explanation of the symbols in the attached diagram]

[0063] 100: Ceramic waveguide filter; 111: First resonant block; 112: Second resonant block; 113: Third resonant block; 114: Fourth resonant block; 115: Fifth resonant block; 116: Sixth resonant block; 117: Seventh resonant block; 118: Eighth resonant block; 121: First resonator; 122: Second resonator; 123: Third resonator; 124: Fourth resonator; 125: Fifth resonator; 126: Sixth resonator; 127: Seventh resonator; 128: Eighth resonator; 131: Input terminal; 132: Output terminal; 141-146: Front-end delay adjustment unit; 150: Barrier wall; 151: Cavity; 161-163: Slots

[0064] [Cross-references to related applications]

[0065] This patent application claims priority to Korean Patent Application No. 10-2021-0032426, filed on March 12, 2021 with the Korean Intellectual Property Office, the contents of which are incorporated herein by reference.

Claims

1. A ceramic waveguide filter comprising a plurality of resonant blocks of ceramic dielectric, characterized in that, The filter includes: The input and output terminals are formed in the form of grooves with a predetermined depth on the outer surface of the ceramic waveguide filter. Multiple resonators are formed in the form of grooves with a predetermined depth on the outer surface of each of the multiple resonant blocks; At least one front-end delay adjustment unit is adjacent to at least one of the input and the output terminals and is formed in a groove shape with a predetermined depth on the outer surface of the ceramic waveguide filter; and At least one slot, on at least a portion of the region between adjacent resonant blocks in the plurality of resonant blocks, has a predetermined depth on at least one of the upper and lower surfaces of the ceramic waveguide filter. At least one portion of the at least one front-end delay adjustment unit is arranged to overlap with different slots in the at least one slot to form a groove with a predetermined depth. The front-end delay adjustment unit is configured to adjust the variation range of at least one of the input front-end delay and the output front-end delay by adjusting at least one of the slot depth and slot width formed on each front-end delay adjustment unit.

2. The ceramic waveguide filter as described in claim 1, characterized in that, The at least one front-end delay adjustment unit is located on at least one of the upper or lower surfaces of the ceramic waveguide filter.

3. The ceramic waveguide filter as described in claim 1, characterized in that, The at least one front-end delay adjustment unit, which is arranged overlapping the slot, has a semi-circular cross-section.

4. The ceramic waveguide filter as described in claim 1, characterized in that, The at least one front-end delay adjustment unit has a cylindrical or N-prism shape, where N is a natural number greater than or equal to 3.

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