Filter module

Abstract

The present invention relates to a filter module including an inductor implemented in the form of a pattern and a commercial capacitor element to increase space efficiency and maximize low loss characteristics. The filter module includes: a first layer in which a plurality of capacitor elements are arranged and which includes a first inductor pattern; a second layer which is spaced apart from the first layer and includes a second inductor pattern; and a third layer arranged between the first layer and the second layer, wherein the first inductor pattern and the second inductor pattern are electrically connected to each other, and an expensive inductor is implemented in the form of a pattern, and a commercial capacitor element is used, to thereby reduce manufacturing costs, lower insertion loss, and reduce the thickness.

Description

Filter module

[0001] The present invention relates to a filter module that includes an inductor implemented in a pattern and a commercial capacitor element, thereby maximizing space efficiency and low loss characteristics.

[0002] Filters that filter signals in a desired frequency band can be applied to various devices or fields, including antennas. These bandpass filters are composed of inductors and capacitors. By utilizing the resonant characteristics of the combination of inductors and capacitors at a specific frequency, the coupling coefficient of the resonant period can be adjusted to create filters with various pass bandwidths.

[0003] If these band-pass filters are implemented using a pattern that directly designs both the inductor and capacitor, which are lumped integer elements, various problems arise, such as increased insertion loss, increased signal distortion, increased thickness or size, increased cost when using low-loss materials, and increased process sensitivity due to electromagnetic coupling between elements. Therefore, research is being conducted on this.

[0004] The present invention aims to provide a filter module having low insertion loss and a thin thickness.

[0005] Another object of the present invention is to implement an inductor in a pattern and reduce the manufacturing cost of a filter module by using commercial capacitor elements.

[0006] Another object of the present invention is to provide a filter module capable of reducing the range of performance variation by configuring commercial capacitors in parallel.

[0007] To achieve this purpose, a filter module according to the present invention comprises a first layer having a plurality of capacitor elements arranged thereon and including a first inductor pattern; a second layer spaced apart from the first layer and including a second inductor pattern; and a third layer arranged between the first layer and the second layer, wherein the first inductor pattern and the second inductor pattern are electrically connected.

[0008] In the filter module according to the present invention, the first inductor pattern and the second inductor pattern can be connected through a via.

[0009] In the filter module according to the present invention, the first layer may include a transmission line that receives an external signal through one end and outputs a signal to the outside through the other end.

[0010] In the filter module according to the present invention, the transmission line and the first inductor pattern can be arranged on the same plane.

[0011] In the filter module according to the present invention, the transmission line may have a straight shape.

[0012] In the filter module according to the present invention, the plurality of capacitor elements can be electrically connected to the transmission line.

[0013] In the filter module according to the present invention, the plurality of capacitor elements include a first capacitor element group and a second capacitor element group that are in parallel with each other, and the first capacitor element group and the second capacitor element group can be arranged symmetrically with respect to the transmission line.

[0014] In the filter module according to the present invention, the first capacitor element group includes a second capacitor element connected in series with the first capacitor element, and the first capacitor element and the second capacitor element can be arranged side by side in a direction parallel to the direction in which the transmission line extends.

[0015] In the filter module according to the present invention, the first layer may include the first inductor pattern disposed between the first capacitor element and the third capacitor element, and the first inductor pattern may include a via hole overlapping in a second direction perpendicular to the first direction in which the transmission line extends.

[0016] In the filter module according to the present invention, the first inductor pattern may include a plurality of inductors that are alternately arranged with respect to the transmission line.

[0017] In the filter module according to the present invention, the plurality of inductors may have an asymmetrical structure with respect to the transmission line.

[0018] In the filter module according to the present invention, the extension directions of the patterns adjacent to each other in the first direction among the plurality of inductors may be different from each other.

[0019] In the filter module according to the present invention, a plurality of inductors alternately arranged with respect to the transmission line can be electrically connected to the transmission line through a stub pattern.

[0020] In the filter module according to the present invention, the stub pattern has a width wider than the widths of the plurality of inductors and the transmission line, and at least a portion of the stub pattern may overlap with the first inductor pattern in a second direction perpendicular to the first direction in which the transmission line extends.

[0021] In the filter module according to the present invention, the stub pattern may include a first stub pattern and a second stub pattern that overlap each other in the first-first direction.

[0022] The filter module according to the present invention can reduce the range of variation in performance, have low insertion loss, and have a thin thickness by implementing an inductor in a pattern and arranging commercial capacitor elements in parallel.

[0023] FIG. 1a is an exploded perspective view of a filter module according to one embodiment of the present invention.

[0024] FIG. 1b is a schematic perspective view of a filter module according to an embodiment of the present invention.

[0025] Figure 2 shows an equivalent circuit of a filter module according to one embodiment.

[0026] FIG. 3 is a plan view showing a first layer of a filter module according to one embodiment of the present invention.

[0027] Fig. 4a is an external perspective view of the perspective view of Fig. 1 with the first layer removed.

[0028] Figure 4b is a plan view of the second layer.

[0029] Fig. 5a is an external perspective view of the perspective view of Fig. 4a with the second layer removed.

[0030] Figure 5b is a plan view of the third layer.

[0031] Fig. 6a is an external perspective view of the fourth layer with the third layer removed from the perspective view of Fig. 5a.

[0032] Figure 6b is a plan view of the fourth layer.

[0033] Figures 7a and 7b are graphs showing the frequency-dependent transmission characteristics of the filter module according to the present invention.

[0034] Figures 8a and 8b are graphs showing the frequency-dependent Q value (Quality factor) and capacitor characteristics of a pattern-shaped capacitor and a commercial capacitor element.

[0035] With respect to the embodiments of the present invention disclosed in the text, specific structural and functional descriptions are merely illustrative for the purpose of explaining the embodiments of the present invention, and the embodiments of the present invention may be implemented in various forms and should not be construed as being limited to the embodiments described in the text.

[0036] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the present invention to specific disclosed forms, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0037] While terms like "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0038] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components in between. Conversely, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as "between" and "immediately between" or "adjacent to" and "directly adjacent to", should be interpreted similarly.

[0039] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprises" or "has" indicate the presence of a disclosed feature, number, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0040] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant technology, and shall not be construed in an idealized or overly formal sense unless explicitly defined herein.

[0041] Meanwhile, if a particular embodiment can be implemented differently, the functions or operations specified within a particular block may occur in a different order than specified in the flowchart. For example, two consecutive blocks may actually be performed substantially simultaneously, or, depending on the related functions or operations, the blocks may be performed in reverse order.

[0042] Hereinafter, a filter module according to the present invention will be described with reference to the attached drawings.

[0043] FIG. 1A is an exploded perspective view of a filter module according to an embodiment of the present invention, and FIG. 1B is a schematic external perspective view of the filter module according to an embodiment of the present invention. As illustrated, the filter module according to the present invention is composed of a plurality of layers, for example, four layers. The filter module according to the present invention includes a first layer (Layer 1) on which a plurality of capacitor element groups (CG1, CG2) are arranged and a first inductor pattern (LP1), a third layer (Layer 3) spaced apart from the first layer (Layer 1) and including a second inductor pattern (LP2), a second layer (Layer 2) arranged between the first layer (Layer 1) and the third layer (Layer 3), and a fourth layer (Layer 4) arranged below the third layer (Layer 3). The second layer (Layer 2) includes a first via pattern (VP1) for electrically connecting a first inductor pattern (LP1) disposed on the first layer (Layer 1) and a second inductor pattern (LP2) disposed on the third layer (Layer 3). The fourth layer (Layer 4) includes a second via pattern (VP2) for electrically connecting the second inductor pattern (LP2) disposed on the third layer (Layer 3) to ground.

[0044] Fig. 2 shows an equivalent circuit of a filter module according to an embodiment. The filter module according to the embodiment illustrated in Fig. 2 is a type of band-pass filter and includes a plurality of inductors (L1, L2, L3, L4, L11, L12, L13, L14, L15, L16, L21, L22, L23, L24, L25, L31, L32, L33, L34, L35, Li, Lo) and a plurality of capacitors (C1, C2, C3, C4, C21, C22, C23, C24, C25, C31, C32, C33, C34, C35, Ci, Co).

[0045] The first port (P1) is connected to one end of the eleventh inductor (L11) and one end of the input inductor (Li) via the ninth node (N9). An input port capacitor (Ci) may be connected between the input port inductor (Li) and ground. The other end of the eleventh inductor (L11) may be connected to the tenth node (10). One end of the first capacitor (C1) and one end of the twelfth inductor (L12) may be connected to the tenth node (N10). A first capacitor (C1) and a first inductor (L1) may be connected in series between the tenth node (N10) and the first node (N1). A second capacitor (C2) and a second inductor (L2) may be connected in series between the first node (N1) and the second node (N2). A third capacitor (C3) and a third inductor (L3) may be connected in series between the second node (N2) and the third node (N3). A fourth capacitor (C4) and a fourth inductor (L4) may be connected in series between the third node (N3) and the fourteenth node (N14). A transmission line composed of a plurality of inductors (L11 to L16) may be connected in series between the first port (P1) and the second port (P2).

[0046] A 21st inductor (L21) and a 31st inductor (L31) may be connected in series between the 16th node (N16) and the 26th node (N26). A 21st capacitor (C21) may be connected between the 16th node (N16) and the ground. A 31st capacitor (C31) may be connected between the 21st node (N21) and the ground between the 21st inductor (L21) and the 31st inductor (L31). The 31st inductor (L31) and the 31st capacitor (C31) may be connected in parallel between the 21st node (N21) and the 26th node (N26). The 21st capacitor (C21) between the 16th node (N16) and the 26th node (N26) can be connected in parallel with the 21st inductor (L21) and the 31st inductor (L31) which are connected in series with each other.

[0047] A 22nd inductor (L22) and a 32nd inductor (L32) may be connected in series between the 17th node (N17) and the 27th node (N27). A 22nd capacitor (C22) may be connected between the 17th node (N17) and the ground. A 32nd capacitor (C32) may be connected between the 22nd node (22) and the ground between the 22nd inductor (L22) and the 32nd inductor (L32). The 32nd inductor (L32) and the 32nd capacitor (C32) may be connected in parallel between the 22nd node (N22) and the 27th node (N27). The 22nd capacitor (C22) between the 17th node (N17) and the 27th node (N27) can be connected in parallel with the 22nd inductor (L22) and the 32nd inductor (L32), which are connected in series with each other.

[0048] A 23rd inductor (L23) and a 33rd inductor (L33) may be connected in series between the 18th node (N18) and the 28th node (N28). A 23rd capacitor (C23) may be connected between the 18th node (N18) and the ground. A 33rd capacitor (C33) may be connected between the 23rd node (23) and the ground between the 23rd inductor (L23) and the 33rd inductor (L33). The 33rd inductor (L33) and the 33rd capacitor (C33) may be connected in parallel between the 23rd node (N23) and the 28th node (N28). The 23rd capacitor (C23) between the 18th node (N18) and the 28th node (N28) can be connected in parallel with the 23rd inductor (L23) and the 33rd inductor (L33), which are connected in series with each other.

[0049] A 24th inductor (L24) and a 34th inductor (L34) may be connected in series between the 19th node (N19) and the 29th node (N29). A 24th capacitor (C24) may be connected between the 19th node (N19) and the ground. A 34th capacitor (C34) may be connected between the 24th node (24) and the ground between the 24th inductor (L24) and the 34th inductor (L34). The 34th inductor (L34) and the 34th capacitor (C34) may be connected in parallel between the 24th node (N24) and the 29th node (N29). The 24th capacitor (C24) between the 19th node (N19) and the 29th node (N29) can be connected in parallel with the 24th inductor (L24) and the 34th inductor (L34) which are connected in series with each other.

[0050] A 25th inductor (L25) and a 35th inductor (L35) may be connected in series between the 20th node (N20) and the 30th node (N30). A 25th capacitor (C25) may be connected between the 20th node (N20) and the ground. A 35th capacitor (C31) may be connected between the 25th node (25) and the ground between the 25th inductor (L25) and the 35th inductor (L35). The 35th inductor (L35) and the 35th capacitor (C35) may be connected in parallel between the 25th node (N25) and the 30th node (N30). The 25th capacitor (C25) between the 20th node (N20) and the 30th node (N30) can be connected in parallel with the 25th inductor (L25) and the 35th inductor (L35), which are connected in series with each other.

[0051] One end of the 16th inductor (L16) may be connected to the second port (P2). An output port inductor (Lo) and an output port capacitor (Co) may be connected in series between the 15th node (N15) between the 16th inductor (L16) and the second port (P2) and the ground.

[0052] The first port (P1) may be an input port from which a signal enters, and the second port (P2) may be an output port from which a signal is output. Alternatively, the first port (P1) may be an output port from which a signal is output, and the second port (P2) may be an input port from which a signal enters.

[0053] FIG. 3 is a plan view illustrating a first layer (Layer 1) of a filter module according to an embodiment of the present invention. As illustrated, a transmission line (TL) is formed on the first layer (Layer 1), one end of which receives an external signal and the other end of which outputs a signal to the outside. The transmission line (TL) is arranged on the same plane of the first layer (Layer 1) as the first inductor pattern (LP1). The transmission line (TL) has a straight line shape.

[0054] A plurality of capacitor element groups (CG1, CG2) are connected to the transmission line (TL) having a straight shape. The plurality of capacitor element groups (CG1, CG2) include a first capacitor element group (CG1) and a second capacitor element group (CG2) that are connected in parallel with each other. The first capacitor element group (CG1) and the second capacitor element group (CG2) are arranged symmetrically with respect to the transmission line (TL).

[0055] The first capacitor element group (CG1) includes a plurality of capacitor elements (C1L, C2L, C3L, C4L) that are arranged in series on the left side with respect to the transmission line (TL). The second capacitor element group (CG2) includes a plurality of capacitor elements (C1R, C2R, C3R, C4R) that are arranged in series on the right side with respect to the transmission line (TL). At this time, the capacitance of the plurality of capacitor elements (C1L, C2L, C3L, C4L) that form the first capacitor element group (CG1) may be different from the capacitance of the plurality of capacitor elements (C1R, C2R, C3R, C4R) that form the second capacitor element group (CG2).

[0056] A first inductor pattern (LP1) arranged on a first layer (L1) includes a plurality of inductors (L1, L2, L3, L4, L5). The embodiment is not limited to the number or arrangement positions of the inductors constituting the inductor pattern. The plurality of inductors (L1, L2, L3, L4, L5) may be arranged alternately with respect to the transmission line (TL). At this time, the first inductor pattern (LP1) may be arranged in an asymmetrical structure with respect to the transmission line (TL). For example, among the plurality of inductors, the first inductor (L1), the third inductor (L3), and the fifth inductor (L5) may be arranged on the left with respect to the transmission line (TL), and the second inductor (L2) and the fourth inductor (L4) may be arranged on the right with respect to the transmission line (TL). Accordingly, the extension directions of the first inductor (L1), the third inductor (L3), and the fifth inductor (L5), which are adjacent to each other in the first direction among the plurality of inductors, are different from the extension directions of the second inductor (L2) and the fourth inductor (L4), which are adjacent to each other in the first direction.

[0057] A plurality of inductors (L1, L2, L3, L4, L5) alternately arranged with respect to the transmission line (TL) can be electrically connected to the transmission line (TL) via a stub pattern (SP). That is, the transmission line (TL) and the first inductor pattern (LP1) can be electrically connected by being arranged on top of the stub pattern (SP).

[0058] The stub pattern (SP) has a width wider than the widths of the first inductor pattern (LP1) and the transmission line (TL). A portion of the stub pattern (SP) overlaps the first inductor pattern (LP1) in a second direction perpendicular to the first direction in which the transmission line (TL) extends. The stub pattern (SP) may include a first stub (Stub1) and a second stub (Stub2) that overlap in the first direction in which the transmission line (TL) extends.

[0059] Fig. 4a shows an external perspective view of the perspective view of Fig. 1 with the first layer (Layer 1) removed, and Fig. 4b shows a plan view of the second layer (Layer 2).

[0060] As mentioned above, the second layer (Layer 2) includes a via pattern (VP1) for electrically connecting the first inductor pattern (LP1) of the first layer (Layer) and the second inductor pattern (LP2) of the third layer (Layer 3). The via pattern (VP1) includes a plurality of vias (VA1L to VA12L) arranged on the left side with respect to the transmission line (illustrated in the first layer) and a plurality of vias (VA1R to VA10R) arranged on the right side.

[0061] Fig. 5a is an external perspective view of the second layer (Layer 2) removed from the perspective view of Fig. 4a, and Fig. 5b is a plan view of the third layer (Layer 3). As illustrated, a second inductor pattern (LP2) is arranged on the third layer (Layer 3). The second inductor pattern (LP2) includes a plurality of inductors (L1-3, L2-3, L3-3, L4-3, L5-3). Among the plurality of inductors, a plurality of inductors (L1-3, L3-3, L5-3) are arranged on the left side of a transmission line (TL) formed on the first layer (Layer), and a plurality of inductors (L2-3, L4-3) are arranged on the right side symmetrical to the transmission line (TL).

[0062] The first inductor (L1-3) of the third layer (Layer 3) is connected to the first inductor (L1) of the first layer (Layer 1) through a via (VA2L), the second inductor (L2-3) of the third layer (Layer 3) is connected to the second inductor (L2) of the first layer (Layer 1) through a via (VA3R), the third inductor (L3-3) of the third layer (Layer 3) is connected to the third inductor (L3) of the first layer (Layer 1) through a via (VA7L), the fourth inductor (L4-3) of the third layer (Layer 3) is connected to the fourth inductor (L4) of the first layer (Layer 1) through a via (VA7R), and the fifth inductor (L5-3) of the third layer (Layer 3) is connected to the It is connected to the fifth inductor (L5) of the first layer (Layer 1) through a via (VA12L).

[0063] Fig. 6a is an external perspective view of the perspective view of Fig. 5a with the third layer (Layer 3) removed, and Fig. 6b is a plan view of the fourth layer (Layer 4). The fourth layer (Layer 4) includes a second via pattern (VP2) for electrically connecting the second inductor pattern (LP2) arranged on the third layer (Layer 3) to the ground. The second via pattern (VP2) may be formed at a position vertically overlapping the first via pattern (VP1) of the second layer.

[0064] FIG. 7A and FIG. 7B are graphs showing the frequency-dependent characteristics of the filter module according to the present invention. Here, reference symbol S11 in FIG. 7A represents the amount of a returning signal, and S21 represents the amount of a signal arriving at the output terminal. The sum of S11 and S21 is 1. Through the two graphs, it can be seen that signals in a frequency band of 5.8 GHz or higher are transmitted to the output terminal. FIG. 7B shows the amount of a returning signal and the amount of a signal arriving at the output terminal when capacitors are configured in parallel. As can be seen from the graph, signals in the frequency band of 5.85 GHz to 7.10 GHz pass through, and signals in other frequency bands are blocked by the capacitors configured in parallel.

[0065] Figures 8a and 8b are graphs showing the characteristics of the Q value (Quality Factor) and capacitance by frequency of a commercial capacitor element when the capacitor is implemented in the form of a pattern.

[0066] When a pattern-shaped capacitor is used, as in Fig. 8a, the Q value by frequency is shown as graph "a", and when a commercial capacitor element is used, the Q value by frequency is shown as graph "b". That is, it can be seen that a high Q value can be achieved when a commercial capacitor is used.

[0067] When a pattern-shaped capacitor is used, as in Fig. 8b, the capacitor value by frequency is shown as the "c" graph, and when a commercial capacitor element is used, the capacitor value by frequency is shown as the "d" graph. That is, it can be seen that a high capacitor value can be obtained in the high-frequency band when a commercial capacitor is used.

[0068] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

[0069] The filter module according to the present invention can be used in a technical field utilizing wireless signals.

Claims

1. A first layer having a plurality of capacitor elements arranged thereon and including a first inductor pattern; a third layer spaced apart from the first layer and including a second inductor pattern; and comprising a second layer positioned between the first layer and the third layer; The above first inductor pattern and the above second inductor pattern are electrically connected filter modules.

2. In paragraph 1, A filter module in which the first inductor pattern and the second inductor pattern are connected through a via.

3. In paragraph 1, The above first layer is a filter module including a transmission line that receives an external signal through one end and outputs a signal to the outside through the other end.

4. In paragraph 3, A filter module in which the above transmission line and the first inductor pattern are arranged on the same plane.

5. In paragraph 3, The above transmission line is a filter module having a straight line shape.

6. In paragraph 5, The above plurality of capacitor elements are a filter module electrically connected to the transmission line.

7. In paragraph 6, The above plurality of capacitor elements include a first capacitor element group and a second capacitor element group that are in parallel with each other. A filter module in which the first capacitor element group and the second capacitor element group are arranged symmetrically with respect to the transmission line.

8. In paragraph 7, The above first capacitor element group includes a second capacitor element connected in series with the first capacitor element, A filter module in which the first capacitor element and the second capacitor element are arranged side by side in a direction parallel to the direction in which the transmission line extends.

9. In the 8th paragraph, the first layer, A first inductor pattern is included, which is arranged between the first capacitor element and the second capacitor element. A filter module in which the first inductor pattern includes a via hole overlapping in a second direction perpendicular to the first direction in which the transmission line extends.

10. In paragraph 4, The above first inductor pattern is a filter module including a plurality of inductors alternately arranged with respect to the transmission line.

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