Filter device and communication apparatus

Abstract

To provide a filter device with improved output characteristics.SOLUTION: A first direction (71), which is a signal propagation direction at one end of a first inductor (51) whose one end (51a) is connected to a common terminal (10), and a second direction (72), which is a signal propagation direction at one end of a second inductor (52) whose one end (52a) is connected to a second connection path between the common terminal and a second filter, are oriented away from each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a filter device and a communication apparatus including the filter device. [Background technology]

[0002] Patent Document 1 discloses a high-frequency module in which a sub-propagation path is formed in addition to a main propagation path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] WO2015 / 104882 Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure provides a filter device or the like with improved output characteristics. [Means for solving the problem]

[0005] In order to solve the above problem, a filter device according to one embodiment of the present disclosure includes a common terminal, a first terminal, a second terminal, a first filter connected between the common terminal and the first terminal, a second filter connected between the common terminal and the second terminal, a first inductor in a first connection path between the common terminal and the first filter, the first inductor having one end connected to the common terminal and the other end connected to the first filter, and a second inductor having one end connected to a second connection path between the common terminal and the second filter and the other end connected to ground, wherein a first direction which is the propagation direction of a signal from the common terminal at a start point of the first inductor and a second direction which is the propagation direction of a signal from the common terminal at a start point of the second inductor are directions away from each other. [Effects of the Invention]

[0006] According to one aspect of the present disclosure, a filter device or the like with improved output characteristics can be realized. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a circuit diagram illustrating an example of a filter device according to a first embodiment of the present disclosure. [Figure 2] 1 is an exploded perspective view showing an example of the structure of a filter device according to a first embodiment of the present disclosure. [Figure 3] FIG. 10 is an exploded perspective view showing an example of the structure of a filter device according to a second embodiment of the present disclosure. [Figure 4] FIG. 11 is an exploded perspective view showing an example of the structure of a filter device according to a third embodiment of the present disclosure. [Figure 5] FIG. 10 is a diagram showing an example of current density distribution in a filter device according to a third embodiment and a filter device according to the first embodiment of the present disclosure. [Figure 6] 10 is a graph showing an example of an output signal at a second terminal of a filter device according to a third embodiment of the present disclosure and a filter device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] [Embodiment 1] An embodiment of the present disclosure will be described in detail below.

[0009] 1 is a circuit diagram illustrating an example of a filter device 1 according to a first embodiment of the present disclosure. As shown in FIG. 1, the filter device 1 includes a common terminal 10, a first terminal 21, a second terminal 22, a first filter 31, a second filter 32, a first connection path 41, a second connection path 42, a first inductor 51, and a second inductor 52.

[0010] The common terminal 10 is an input terminal through which a signal is input to the filter device 1. The first terminal 21 is an output terminal through which low-frequency components of the signal input to the common terminal 10 are output. The second terminal 22 is an output terminal through which high-frequency components of the signal input to the common terminal 10 are output.

[0011] The first filter 31 is a frequency filter that attenuates frequency components outside a predetermined pass band of a signal input to the common terminal 10 and outputs the signal to the first terminal 21. The second filter 32 is a frequency filter that attenuates frequency components outside a predetermined pass band of a signal input to the common terminal 10 and outputs the signal to the second terminal 22. As the first filter 31 and the second filter 32, any known frequency filter can be used without any particular restrictions.

[0012] The center frequency of the pass band of the first filter 31 is lower than the center frequency of the pass band of the second filter 32. Specifically, the center frequency of the pass band of the first filter 31 may be half or less of the center frequency of the pass band of the second filter 32. Furthermore, the center frequency of the pass band of the first filter 31 may be less than 3 GHz, and the center frequency of the pass band of the second filter 32 may be 3 GHz or higher.

[0013] The first connection path 41 is a path between the common terminal 10 and the first filter 31. The first inductor 51 is an inductor in the first connection path 41, having one end 51a connected to the common terminal 10 and the other end 51b connected to the first filter 31.

[0014] The second connection path 42 is a path between the common terminal 10 and the second filter 32. The second inductor 52 is an inductor having one end 52a connected to the second connection path and the other end 52b connected to ground 80.

[0015] A plurality of circuit elements may be arranged in the second connection path 42. In the example shown in Fig. 1, the second connection path 42 includes an inductor L11, a capacitor C21, a capacitor C22, and an inductor L22 arranged in series in this order from the common terminal 10 toward the second filter 32. In addition, the capacitor C20 is connected between the capacitor C21 and the capacitor C22.

[0016] One end 52a of the second inductor 52 is connected to the side of the capacitor C20 opposite to the side connected to the capacitors C21 and C22. In other words, one end 52a of the second inductor 52 is connected between the capacitors C21 and C22 via the capacitor C20. The circuit elements arranged in the second connection path 42 are not limited to these; for example, the inductor L11 may be omitted, or another circuit element may be added.

[0017] The second inductor 52 and the multiple circuit elements arranged on the second connection path 42 may form a matching circuit, which can reduce power loss in the filter device 1.

[0018] (Filter device structure) Fig. 2 is an exploded perspective view showing an example of the structure of the filter device 1 according to the first embodiment of the present disclosure. As shown in Fig. 2, the filter device 1 includes, in addition to the components shown in Fig. 1, a bottom layer substrate 61, a top layer substrate 62, and a plurality of inductor substrates 63 positioned therebetween. The bottom layer substrate 61, the top layer substrate 62, and the inductor substrates 63 may all be formed of an insulator.

[0019] 2 shows only three layers of inductor substrates 63. However, the filter device 1 may include more inductor substrates 63. In the following description, in the stacking direction in which the bottom layer substrate 61, the multiple inductor substrates 63, and the top layer substrate 62 are stacked, the side of the top layer substrate 62 may be referred to as the upper side, and the side of the bottom layer substrate 61 may be referred to as the lower side.

[0020] The bottom layer substrate 61 is a substrate on which the common terminal 10 is arranged. A ground terminal 61a may also be arranged on the bottom layer substrate 61. The surface layer substrate 62 is a substrate on which the first filter 31, the second filter 32, and a plurality of circuit elements (see FIG. 1) arranged in the second connection path 42 are mounted.

[0021] The inductor substrate 63 is a substrate on which the first inductor 51 and the second inductor 52 are formed. Specifically, on each of the multiple inductor substrates 63, both the first inductor 51 and the second inductor 52 are formed by a conductor, each half-way around the substrate. In the following description, a portion of the first inductor 51 formed on each of the inductor substrates 63 will be simply referred to as the first inductor 51. Furthermore, a portion of the second inductor 52 formed on each of the inductor substrates 63 will be simply referred to as the second inductor 52.

[0022] The first inductor 51 and the second inductor 52 do not need to overlap each other when viewed from the stacking direction in which the inductor substrates 63 are stacked. Therefore, as described above, both the first inductor 51 and the second inductor 52 can be formed on each inductor substrate 63. This allows the filter device 1 to be made smaller than when the first inductor 51 and the second inductor 52 overlap each other when viewed from the stacking direction.

[0023] The common terminal 10 arranged on the bottom layer substrate 61 and the first inductor 51 formed on the inductor substrate 63 adjacent to the top side of the bottom layer substrate 61 are electrically connected through a conductor arranged in a via 63a, which is an opening formed in the inductor substrate 63. The first inductors 51 formed on adjacent inductor substrates 63 are electrically connected through a conductor arranged in a via 63b, which is an opening formed in the upper inductor substrate 63. The first filter 31 arranged on the surface substrate 62 and the first inductor 51 formed on the inductor substrate 63 adjacent to the bottom side of the surface substrate 62 are electrically connected through a conductor arranged in a via 63c, which is an opening formed in the surface substrate 62.

[0024] The common terminal 10 arranged on the bottom layer substrate 61 and the second connection path 42 are connected by a path not shown. The second connection path 42 and the second filter 32 are connected on the surface layer substrate 62.

[0025] The second connection path 42 and the second inductor 52 formed on the inductor substrate 63 adjacent to the lower side of the surface substrate 62 are electrically connected through a conductor arranged in a via 63d, which is an opening formed in the surface substrate 62. The second inductors 52 formed on adjacent inductor substrates 63 are electrically connected through a conductor arranged in a via 63e, which is an opening formed in the upper inductor substrate 63. The ground terminal 61a arranged on the lowermost substrate 61 and the second inductor 52 formed on the inductor substrate 63 adjacent to the upper side of the lowermost substrate 61 are electrically connected through a conductor arranged in a via 63f, which is an opening formed in the inductor substrate 63.

[0026] 2, a first direction 71 indicates the propagation direction of a signal from the common terminal 10 at one end 51a of the first inductor 51. The one end 51a of the first inductor 51 is the point of the conductor that constitutes the first inductor 51 on the inductor substrate 63 that is closest to the common terminal 10 in the propagation direction of the signal from the common terminal 10. A second direction 72 indicates the propagation direction of a signal from the common terminal 10 at one end 52a of the second inductor 52. The one end 52a of the second inductor 52 is the point of the conductor that constitutes the second inductor 52 on the inductor substrate 63 that is closest to the common terminal 10 in the propagation direction of the signal from the common terminal 10.

[0027] In the filter device 1, the first direction 71 and the second direction 72 are directions that move away from each other. The directions that move away from each other mean that, when defining straight lines that extend along the first direction 71 and the second direction 72, (i) the distance between a straight line that extends along the first direction 71 and a straight line that extends along the second direction 72 increases as the line extends along the first direction 71, and (ii) the distance between a straight line that extends along the second direction 72 and a straight line that extends along the first direction 71 increases as the line extends along the second direction 72. This improves the output characteristics of the filter device 1 compared to when the first direction 71 and the second direction 72 are not directions that move away from each other.

[0028] Specifically, the first direction 71 and the second direction 72 may be directions that are 90° or more apart from each other. In Fig. 2, the first direction 71 and the second direction 72 are directions that are 90° or more apart from each other. This improves the output characteristics of the filter device 1 compared to when the first direction 71 and the second direction 72 are not directions that are 90° or more apart from each other.

[0029] Furthermore, as described above, in the filter device 1, the inductor substrate 63 serving as the first layer on the common terminal 10 side of the first inductor 51 and the inductor substrate 63 serving as the first layer on the common terminal 10 side of the second inductor 52 may be different from each other in the signal propagation direction from the common terminal 10. Specifically, the inductor substrate 63 serving as the first layer of the first inductor 51 may be the inductor substrate 63 adjacent to the upper side of the bottom layer substrate 61. On the other hand, the inductor substrate 63 serving as the first layer of the second inductor 52 may be the inductor substrate 63 adjacent to the lower side of the surface layer substrate 62. This further improves the output characteristics of the filter device 1 compared to when the inductor substrate 63 serving as the first layer of the first inductor 51 and the inductor substrate 63 serving as the first layer of the second inductor 52 are the same.

[0030] 2, the first inductor 51 may include a first inductance portion 511 that generates inductance and a first connection portion 512 that connects the first inductance portion 511 and the common terminal 10. In this case, the first direction 71 may be the signal propagation direction in the first connection portion 512. In other words, when the first inductor 51 includes the first inductance portion 511 and the first connection portion 512, the signal propagation direction at the start point of the first inductance portion 511 does not necessarily have to be a direction away from the second direction 72. The start point of the first inductance portion 511 is the boundary point between the first inductance portion 511 and the first connection portion 512.

[0031] For example, when the first inductor 51 includes the first inductance portion 511 and the first connecting portion 512, the signal propagation direction at the starting point of the first inductance portion 511 may be the same as the second direction 72, as shown in Fig. 2. Therefore, when the first inductor 51 includes the first inductance portion 511 and the first connecting portion 512, the degree of freedom in designing the filter device 1 is improved.

[0032] The first inductor 51 does not necessarily have to include the first connecting portion 512. If the first inductor 51 does not include the first connecting portion 512, the first inductance portion 511 is directly connected to the common terminal 10.

[0033] 2, the filter device 1 may not have another capacitor or inductor between the first inductor 51 and the second inductor 52. The other capacitor or inductor here includes one that is not electrically connected to the first inductor 51 or the second inductor 52. This improves the output characteristics of the filter device 1 compared to when the filter device 1 has another capacitor or inductor between the first inductor 51 and the second inductor 52.

[0034] The filter device 1 may be included in, for example, a communication device. A communication device including the filter device 1 is also included in one aspect of the present disclosure.

[0035] [Embodiment 2] Other embodiments of the present disclosure will be described below. For convenience of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0036] 3 is an exploded perspective view showing an example of the structure of a filter device 1A according to embodiment 2 of the present disclosure. As shown in FIG. 3, filter device 1A differs from filter device 1 in that it includes a second inductor 52A instead of second inductor 52.

[0037] The second inductor 52A includes a second inductance portion 521 that generates inductance and a second connection portion 522 that connects the second inductance portion 521 and the second connection path 42. In this case, the second direction 72 may be the signal propagation direction in the second connection portion. That is, when the second inductor 52 includes the second inductance portion 521 and the second connection portion 522, the signal propagation direction at the start point of the second inductance portion 521 does not necessarily need to be a direction away from the first direction 71. The start point of the second inductance portion 521 is the boundary between the second inductance portion 521 and the second connection portion 522. Therefore, the second inductor 52 includes the second inductance portion 521 and the second connection portion 522, which improves the design freedom of the filter device 1A.

[0038] [Embodiment 3] 4 is an exploded perspective view showing an example of the structure of a filter device 1B according to embodiment 3 of the present disclosure. As shown in FIG. 4, filter device 1B differs from filter device 1 in that it includes a second inductor 52B instead of second inductor 52.

[0039] The second direction 72 in the second inductor 52B may be opposite to the first direction 71. That is, in the filter device 1B, the first direction 71 and the second direction 72 may be 180° apart from each other. This improves the output characteristics of the filter device 1B compared to the output characteristics of the filter device 1.

[0040] (Comparison of output characteristics) 5 is a graph showing an example of current density distribution in a frequency band in which improved attenuation characteristics were confirmed for filter device 1B and filter device 1. In FIG. 5, the current densities in first inductor 51, second inductor 52, and second terminal 22 of filter device 1 are indicated by white circles. The current densities in first inductor 51A, second inductor 52A, and second terminal 22 of filter device 1B are indicated by black circles. In FIG. 5, first inductor 51, second inductor 52, and second terminal 22 are referred to as the L1 section, the L2 section, and the output section, respectively.

[0041] 5, the current density in first inductor 51A and second inductor 52A of filter device 1B was higher than the current density in first inductor 51 and second inductor 52 of filter device 1. On the other hand, the current density at second terminal 22 of filter device 1B was lower than the current density at second terminal 22 of filter device 1. From this, it can be said that in filter device 1B, even more unnecessary current flows through first inductor 51A and second inductor 52A than in filter device 1, and as a result, the current density at second terminal 22 is lower.

[0042] 6 is a graph showing an example of the output signals at second terminal 22 of filter device 1B and filter device 1. In FIG. 6, the horizontal axis represents frequency and the vertical axis represents signal strength. In FIG. 6, the solid line represents the output signal at second terminal 22 of filter device 1B, and the dotted line represents the output signal at second terminal 22 of filter device 1. In the following description, the output signal at second terminal 22 will be simply referred to as the output signal.

[0043] 6, outside the passband of the second filter 32, specifically in the range of 4000 Hz or less, the output signal of the filter device 1B is attenuated more than the output signal of the filter device 1. From this, it can be said that the reason the output signal of the filter device 1B is attenuated more than the output signal of the filter device 1 in the example shown in FIG. 5 is because the signal outside the passband of the second filter 32 is attenuated.

[0044] In general, in a filter device, it is necessary to attenuate as much as possible the current of a signal outside the passband of an output signal. As described in the first embodiment, the filter device 1 exhibits superior output characteristics compared to conventional filter devices. However, it can be said that the filter device 1B exhibits even superior output characteristics compared to the filter device 1.

[0045] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure.

[0046] 〔summary〕 The present disclosure can also be expressed as follows:

[0047] A filter device according to a first aspect of the present disclosure includes a common terminal, a first terminal, a second terminal, a first filter connected between the common terminal and the first terminal, a second filter connected between the common terminal and the second terminal, a first inductor in a first connection path between the common terminal and the first filter, the first inductor having one end connected to the common terminal and the other end connected to the first filter, and a second inductor having one end connected to a second connection path between the common terminal and the second filter and the other end connected to ground, wherein a first direction, which is the propagation direction of a signal from the common terminal at the start point of the first inductor, and a second direction, which is the propagation direction of a signal from the common terminal at the start point of the second inductor, are directions away from each other.

[0048] A filter device according to aspect 2 of the present disclosure is the same as aspect 1, in which the first inductor includes a first inductance portion that generates inductance and a first connection portion that connects the first inductance portion to the common terminal, and the first direction is the signal propagation direction in the first connection portion.

[0049] A filter device according to aspect 3 of the present disclosure is the same as that of aspect 1 or 2, in which the second inductor includes a second inductance section that generates inductance and a second connection section that connects the second inductance section and the second connection path, and the second direction is the signal propagation direction in the second connection section.

[0050] A filter device according to a fourth aspect of the present disclosure is any one of the first to third aspects, wherein the first direction and the second direction are directions that are apart from each other by 90° or more.

[0051] A filter device according to a fifth aspect of the present disclosure is related to the fourth aspect, wherein the first direction and the second direction are directions that are 180° apart from each other.

[0052] A filter device according to a sixth aspect of the present disclosure is the filter device of any one of the first to fifth aspects, in which no other capacitor or inductor is provided between the first inductor and the second inductor.

[0053] A filter device according to aspect 7 of the present disclosure is any one of aspects 1 to 6, further comprising a plurality of inductor substrates on which the first inductor and the second inductor are formed, and in the signal propagation direction from the common terminal, among the plurality of inductor substrates, the inductor substrate that is the first layer on the common terminal side of the first inductor and the inductor substrate that is the first layer on the common terminal side of the second inductor are different from each other.

[0054] A filter device according to an eighth aspect of the present disclosure is any one of the first to seventh aspects, wherein the center frequency of the pass band of the first filter is equal to or less than half the center frequency of the pass band of the second filter.

[0055] A filter device according to a ninth aspect of the present disclosure is the filter device of any one of the first to eighth aspects, wherein the center frequency of the pass band of the first filter is less than 3 GHz, and the center frequency of the pass band of the second filter is 3 GHz or higher.

[0056] A filter device according to a tenth aspect of the present disclosure is any one of the first to ninth aspects, wherein a plurality of circuit elements are arranged in the second connection path, and the second inductor and the plurality of circuit elements form a matching circuit.

[0057] A filter device according to aspect 11 of the present disclosure is any one of aspects 1 to 10, further comprising a plurality of inductor substrates on which the first inductor and the second inductor are formed, wherein the first inductor and the second inductor do not overlap each other when viewed from the stacking direction in which the plurality of inductor substrates are stacked.

[0058] A communication device according to a twelfth aspect of the present disclosure includes the filter device of any one of the first to eleventh aspects. [Explanation of symbols]

[0059] 1,1A,1B Filter Device 10 Common terminal 21 1st terminal 22 2nd terminal 31 First filter 32 Second filter 41 First connecting route 42 Second connecting route 51 First inductor 51a One end 51b Other end 511 First inductance section 512 First connection part 52, 52A, 52B Second inductor 52a One end 52b Other end 521 Second inductance section 522 Second connection part 63 Inductor board 71 1st direction 72 Second direction 80 grand

Claims

1. A common terminal; A first terminal; A second terminal; a first filter connected between the common terminal and the first terminal; a second filter connected between the common terminal and the second terminal; a first inductor in a first connection path between the common terminal and the first filter, the first inductor having one end connected to the common terminal and the other end connected to the first filter; a second inductor having one end connected to a second connection path between the common terminal and the second filter and the other end connected to ground; and a first direction, which is a signal propagation direction from the common terminal at the one end of the first inductor, and a second direction, which is a signal propagation direction from the common terminal at the one end of the second inductor, are directions away from each other; Filter device.

2. The first inductor is a first inductance portion that generates inductance; a first connection portion that connects the first inductance portion and the common terminal; Equipped with The filter device according to claim 1 , wherein the first direction is a signal propagation direction in the first connection portion.

3. The second inductor is a second inductance portion that generates inductance; a second connection portion that connects the second inductance portion and the second connection path; Equipped with The filter device according to claim 1 , wherein the second direction is a signal propagation direction in the second connection portion.

4. The filter device according to claim 1 , wherein the first direction and the second direction are directions that are at least 90° apart from each other.

5. The filter device according to claim 4 , wherein the first direction and the second direction are directions that are 180° apart from each other.

6. The filter device of claim 1 , wherein there are no other capacitors or inductors between the first inductor and the second inductor.

7. further comprising a plurality of inductor substrates on which the first inductor and the second inductor are formed; 2. The filter device of claim 1, wherein, in the signal propagation direction from the common terminal, among the plurality of inductor substrates, the inductor substrate that is the first layer on the common terminal side of the first inductor and the inductor substrate that is the first layer on the common terminal side of the second inductor are different from each other.

8. The filter device according to claim 1 , wherein the center frequency of the pass band of the first filter is equal to or less than half the center frequency of the pass band of the second filter.

9. 2. The filter device according to claim 1, wherein the center frequency of the pass band of the first filter is less than 3 GHz, and the center frequency of the pass band of the second filter is 3 GHz or higher.

10. a plurality of circuit elements are arranged on the second connection path; The filter device according to claim 1 , wherein the second inductor and the plurality of circuit elements form a matching circuit.

11. further comprising a plurality of inductor substrates on which the first inductor and the second inductor are formed; The filter device according to claim 1 , wherein the first inductor and the second inductor do not overlap each other when viewed from a stacking direction in which the plurality of inductor substrates are stacked.

12. A communication device comprising a filter device according to any one of claims 1 to 11.

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