antenna

Abstract

This antenna comprises: a dielectric layer; a first antenna element which is linear and which is provided to a first surface of the dielectric layer; a power supply line which has a power feeding point and which is provided to a second surface which is on the reverse side of the dielectric layer with respect to the first surface; and a first via passing through the dielectric layer and connected to the first antenna element and the power supply line. The power supply line includes a first line section to which the first via is connected, and the line width of the first line section is wider than the width of the first antenna element.

Description

Technical Field

[0001] The present disclosure relates to an antenna. This application claims priority based on Japanese Application No. 2023-046844 filed on March 23, 2023, and incorporates all the descriptions described in the above Japanese application.

Background Art

[0002] In recent years, an antenna for wireless communication mounted on an electronic device may be mounted on a substrate. For example, Patent Document 1 discloses an inverted F-shaped antenna configured by mounting an antenna element on a substrate. (For example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] The antenna according to the embodiment includes a dielectric layer, a linear first antenna element provided on a first surface of the dielectric layer, a feeding line provided on a second surface opposite to the first surface of the dielectric layer and having a feeding point, and a first via penetrating the dielectric layer and connected to the first antenna element and the feeding line. The feeding line includes a first line portion to which the first via is connected. The line width of the first line portion is wider than the width of the first antenna element.

Brief Description of the Drawings

[0005] [Figure 1] FIG. 1 is a plan view showing an example of the antenna according to the first embodiment. [Figure 2] FIG. 2 is a perspective view showing a main part of the antenna. [Figure 3] FIG. 3 is an enlarged view of a main part of the first surface. [Figure 4] Figure 4 is an enlarged view of the main part of the second surface. [Figure 5] Figure 5 is a plan view showing the main parts of the antenna according to the second embodiment. [Figure 6] Figure 6 is a plan view showing the main parts of the antenna according to the third embodiment. [Figure 7] Figure 7 is a plan view showing the main parts of the antenna according to the fourth embodiment. [Figure 8] Figure 8 is a plan view showing the main parts of the antenna according to the fifth embodiment. [Figure 9] Figure 9 is a diagram illustrating the dimensions of each part of the antenna model according to the first embodiment, and shows the dimensions of the feed line. [Figure 10] Figure 10 is a diagram illustrating the dimensions of each part of the antenna model according to the first embodiment, and shows the dimensions of the first antenna element, the second antenna element, and the passive element. [Figure 11] Figure 11 is a Smith chart plotting the input impedance at the power supply points of Comparative Example 1 and Examples 1 to 4. [Figure 12] Figure 12 shows the frequency characteristics of the VSWR for Comparative Example 1 and Examples 1 to 4. [Figure 13] Figure 13 is a Smith chart plotting the input impedance at the feed point of Example 5. [Figure 14] Figure 14 shows the frequency characteristics of the VSWR in Example 5. [Figure 15] Figure 15 is a Smith chart plotting the input impedance at the feed point of Example 6. [Figure 16] Figure 16 shows the frequency characteristics of the VSWR in Example 6. [Figure 17] Figure 17 is a Smith chart plotting the input impedance at the feed point of Example 7. [Figure 18] Figure 18 shows the frequency characteristics of the VSWR in Example 7. [Modes for carrying out the invention]

[0006] [Problems to be Solved by the Present Disclosure] An antenna mounted on a substrate has a simple structure, but on the other hand, means for adjusting antenna characteristics may be limited, and it may be difficult to obtain good VSWR (Voltage Standing Wave Ratio) characteristics in the operating frequency band. Therefore, a method capable of obtaining good VSWR characteristics with a simple structure is desired.

[0007] [Effects of the Present Disclosure] According to the present disclosure, good VSWR characteristics can be obtained.

[0008] [Description of Embodiments of the Present Disclosure] First, the contents of the embodiments will be listed and described. [Overview of Embodiments]

[0009] The inventors of the present application have intensively studied the improvement of the characteristics of an antenna mounted on a substrate (dielectric layer), and have obtained the knowledge that the configuration of the feeding line significantly affects the antenna characteristics as compared with other configurations. The present disclosure has been made based on this knowledge.

[0010] (1) That is, an antenna according to an embodiment of the present disclosure includes a dielectric layer, a linear first antenna element provided on a first surface of the dielectric layer, a feeding line provided on a second surface opposite to the first surface of the dielectric layer and having a feeding point, and a first via that penetrates the dielectric layer and is connected to the first antenna element and the feeding line. The feeding line includes a first line portion to which the first via is connected. The line width of the first line portion is wider than the width of the first antenna element.

[0011] According to the above configuration, since the feeding line has a first line portion having a line width wider than the width of the first antenna element, the VSWR in the peripheral frequency band targeted by the first antenna element can be reduced over a wide range. As a result, good VSWR characteristics can be obtained.

[0012] (2) In the antenna of (1) above, when the power supply line further includes a second line portion that connects the power supply point and the first line portion, the second line portion may be narrower than the line width of the first line portion. In this case, only the necessary portion of the power supply line can be made wider than the width of the first antenna element.

[0013] (3) Also, in the antenna of (1) or (2) above, the power supply line may include a line body having an intersection portion that intersects the first antenna element in a front view of the dielectric layer, and a pair of first stubs extending along the first antenna element from both sides of the intersection portion. In this case, the VSWR characteristics can be effectively improved.

[0014] (4) Further, in the antenna of (1) or (2) above, a linear non-powered element that extends along the longitudinal direction of the first antenna element and is provided on the first surface at a predetermined interval from the first antenna element may be further provided. In this case, the VSWR characteristics can be more effectively improved.

[0015] (5) In any one of the antennas of (1) to (4) above, when the first antenna element has an electrical length corresponding to a first frequency band, the antenna extends along the longitudinal direction of the first antenna element and is provided on the first surface at a predetermined interval from the first antenna element, and a linear second antenna element having an electrical length corresponding to a second frequency band lower than the first frequency band, and a second via that penetrates the dielectric layer and is connected to the second antenna element and the power supply line may be further provided. In this case, by adjusting the width of the first transmission line within a range wider than the width of the first antenna element, the VSWR characteristics in the first frequency band targeted by the first antenna element can be changed without significantly altering the VSWR characteristics in the second frequency band targeted by the second antenna element. As a result, the VSWR characteristics in the first frequency band can be selectively improved.

[0016] (6) In addition, in the antenna described in (5) above, the second antenna element may be provided at a predetermined distance from the side opposite to the side on which the grounding conductor is provided on the first antenna element.

[0017] (7) In addition, in the antenna of (5) or (6) above, the feed line may include a line body having a first intersection that intersects the first antenna element in a front view of the dielectric layer, and a pair of first stubs extending from both sides of the first intersection along the first antenna element. In this case, the VSWR characteristics of the first frequency band can be changed without significantly altering the VSWR characteristics of the second frequency band, thereby effectively improving the VSWR characteristics of the first frequency band.

[0018] (8) In any one of the antennas described in (5) to (7) above, the feed line may also include a line body having a second intersection that intersects the second antenna element in a front view of the dielectric layer, and a pair of second stubs extending from both sides of the second intersection along the second antenna element. In this case, the VSWR characteristics of the first frequency band can be changed without significantly altering the VSWR characteristics of the second frequency band, thereby effectively improving the VSWR characteristics of the first frequency band.

[0019] (9) Any one of the antennas described in (5) to (8) above may further include a linear parasitic element provided on the first surface at a predetermined distance from the side of the first antenna element opposite to the side facing the second antenna element. In this case, the VSWR characteristics of the first frequency band can be changed without significantly altering the VSWR characteristics of the second frequency band, thereby more effectively improving the VSWR characteristics of the first frequency band.

[0020] (10) In any one of the antennas described in (5) to (9) above, the first antenna element may constitute an inverted F-type antenna, and the second antenna element may constitute an inverted L-type antenna.

[0021] (11) In any one of the antennas described in (1) to (10) above, the first antenna element includes an antenna element body to which the first via is connected, and a short-circuit conductor portion connecting a ground conductor portion arranged in parallel with the antenna element body to one end of the antenna element body, wherein the line width of the first line portion may be wider than the line width of the short-circuit conductor portion. In this case, the VSWR characteristics can be effectively improved.

[0022] (12) In the antenna described in (11) above, the first line portion may have an overlapping portion that overlaps with the short-circuit conductor portion when viewed from the front of the dielectric layer.

[0023] [Details of the embodiment] Preferred embodiments will be described below with reference to the drawings. Furthermore, at least some of the embodiments described below may be combined in any way. [Regarding the first embodiment] [Regarding the overall structure] Figure 1 is a plan view showing an example of an antenna 1 according to the first embodiment. Figure 2 is a perspective view showing the main part of the antenna 1. Antenna 1 is, for example, an antenna used for wireless LAN communication. Antenna 1 is an antenna composed of a conductive pattern formed on the substrate (dielectric layer) of an electronic device having wireless LAN communication functionality. In the following explanation, the three mutually orthogonal directions in each figure will be referred to as the X, Y, and Z directions. Also, as shown in Figure 1, one direction of the X direction will be the X1 direction, and the opposite direction of the X1 direction will be the X2 direction. One direction of the Y direction will be the Y1 direction, and the opposite direction of the Y1 direction will be the Y2 direction. One direction of the Z direction will be the Z1 direction, and the opposite direction of the Z1 direction will be the Z2 direction.

[0024] Antenna 1 comprises a dielectric layer 2, a first ground conductor section 4, a second ground conductor section 6, a first antenna element 8, a second antenna element 10, a feed line 12, and a passive element 14. The first antenna element 8 and the second antenna element 10 are antenna elements capable of transmitting and receiving signals with different frequency bands. In other words, the antenna 1 of this embodiment is a multiband antenna capable of transmitting and receiving signals in two frequency bands using the first antenna element 8 and the second antenna element 10.

[0025] The dielectric layer 2 in this embodiment is a dielectric substrate on which various parts such as the first antenna element 8 and the second antenna element 10 are mounted. The dielectric layer 2 is a rigid substrate, but a flexible substrate can also be used. Examples of materials for the dielectric layer 2 include polyimide resin, epoxy resin, PPE resin, and fluororesin. The dielectric layer 2 is arranged along the XY plane.

[0026] In this embodiment, a single-layer substrate having a dielectric layer 2 is used. However, the dielectric layer 2 may constitute part or all of a multilayer substrate having multiple dielectric layers.

[0027] As shown in Figures 1 and 2, the first antenna element 8, the second antenna element 10, the passive element 14, and the first ground conductor 4 are mounted on the first surface 2a of the dielectric layer 2. The first surface 2a is parallel to the XY plane. The first surface 2a is the surface facing the Z2 direction in the dielectric layer 2. The power supply line 12 and the second grounding conductor section 6 are mounted on the second surface 2b of the dielectric layer 2. The second surface 2b is parallel to the XY plane. The second surface 2b is the surface in the dielectric layer 2 that faces in the Z1 direction.

[0028] The first grounding conductor section 4 is a conductor pattern made of copper or the like, mounted on the first surface 2a. The first grounding conductor section 4 has an edge 4a. The edge 4a is the edge on the X2 direction side of the first grounding conductor section 4. The edge 4a is parallel to the Y direction. Furthermore, the second grounding conductor portion 6 is a conductor pattern made of copper or the like, mounted on the second surface 2b. The second grounding conductor portion 6 has an edge portion 6a. The edge portion 6a is the edge portion of the second grounding conductor portion 6 on the X2 direction side. The edge portion 6a is parallel to the Y direction. The position of the edge portion 6a in the X direction is the same as the position of the edge portion 4a in the X direction. The first grounding conductor portion 4 and the second grounding conductor portion 6 are mounted within an area other than the rectangular portion along the edge on the X2 direction side of the dielectric layer 2. Therefore, the first surface 2a has a first region 2a1 and a second region 2a2. The first region 2a1 is the region covered by the first grounding conductor portion 4. The second region 2a2 is the region of the first surface 2a other than the first region 2a1. The edge portion 4a is located at the boundary between the first region 2a1 and the second region 2a2. Furthermore, the second surface 2b has a third region 2b1 and a fourth region 2b2. The third region 2b1 is the region covered by the second grounding conductor portion 6. The fourth region 2b2 is the region of the second surface 2b other than the third region 2b1. The edge portion 6a is located at the boundary between the third region 2b1 and the fourth region 2b2. The position of the edge of the second region 2a2 on the X1 direction and the position of the edge of the fourth region 2b2 on the X1 direction are the same in the X direction.

[0029] [Regarding the first antenna element 8 and the second antenna element 10] Figure 3 is an enlarged view of the main part of the first surface 2a. The first antenna element 8, the second antenna element 10, and the unpowered element 14 are conductive patterns made of copper or the like that are mounted in the second region 2a2 of the first surface 2a. The first antenna element 8 comprises a first antenna element body 8a and a short-circuit conductor portion 8b. The first antenna element body 8a is linear. Note that "linear" refers to a long, narrow shape, including shapes that have a certain width and are long and narrow, such as a band or belt. In this specification, it refers to a long, narrow rectangular shape, such as the first antenna element 8.

[0030] The first antenna element body 8a extends along the Y direction. The first antenna element body 8a is positioned at a predetermined distance from the edge portion 4a. In other words, the first antenna element body 8a is positioned at a predetermined distance on the X1 direction side of the first grounding conductor portion 4. The first antenna element body 8a has a first element end 8a1 and a second element end 8a2. The first element end 8a1 is the end of the first antenna element body 8a on the Y1 direction side. The second element end 8a2 is the end of the first antenna element body 8a on the Y2 direction side.

[0031] The short-circuit conductor portion 8b is connected to the second element end portion 8a2. The short-circuit conductor portion 8b has a rectangular shape. The short-circuit conductor portion 8b extends from the edge portion 4a in the X2 direction. The short-circuit conductor portion 8b connects the second element end portion 8a2 to the first ground conductor portion 4. Therefore, the short-circuit conductor portion 8b short-circuits the second element end portion 8a2. On the other hand, the first element end 8a1 is an open end.

[0032] The second element end 8a2 of the first antenna element body 8a is connected to the side portion 8b1 of the short-circuit conductor portion 8b. In other words, the first antenna element body 8a extends from the side portion 8b1 along the Y direction. Furthermore, the side edge 8a3 of the first antenna element body 8a is aligned with the extension line in the Y direction that follows the tip edge 8b2 of the short-circuit conductor portion 8b. The first antenna element 8 (first antenna element body 8a) has an electrical length corresponding to the first frequency band. In this embodiment, the first frequency band is the band from 5 GHz to 6 GHz.

[0033] The second antenna element 10 is linear. The second antenna element 10 extends along the Y direction. The second antenna element 10 is provided next to the first antenna element 8 (first antenna element body 8a) at a predetermined interval. Therefore, the second antenna element 10 is provided at a predetermined distance from the side opposite to the side (side edge 8a3) where the first grounding conductor portion 4 is provided, on both sides of the first antenna element 8.

[0034] The second antenna element 10 has a third element end 10a and a fourth element end 10b. The third element end 10a is the end of the second antenna element 10 on the Y1 direction side. The fourth element end 10b is the end of the second antenna element 10 on the Y2 direction side. The end 10a of the third element is located closer to the Y1 direction than the end 8a1 of the first element. Also, the end 10b of the fourth element is located closer to the Y2 direction than the end 8a2 of the second element. In other words, the second antenna element 10 is longer than the first antenna element 8. The third element end 10a and the fourth element end 10b are open ends. The second antenna element 10 has a second antenna element body 10c and a stub portion 10d. The second antenna element body 10c is the portion of the second antenna element 10 between the part to which the second via 18 (described later) is connected and the third element end portion 10a. The stub portion 10d is the portion of the second antenna element 10 between the part to which the second via 18 is connected and the fourth element end portion 10b. The second antenna element 10 (second antenna element body 10c) has an electrical length corresponding to the second frequency band. In this embodiment, the second frequency band is the band from 2.4 GHz to 2.5 GHz.

[0035] The parasitic element 14 is linear. The parasitic element 14 extends along the Y direction. The parasitic element 14 is provided between the first antenna element 8 (first antenna element body 8a) and the edge portion 4a. In other words, the parasitic element 14 is provided at a predetermined distance from the side of the first antenna element 8 opposite to the side facing the second antenna element 10. The position of the fifth element end 14a of the passive element 14 in the Y direction is between the first element end 8a1 and the third element end 10a. Also, the position of the sixth element end 14b of the passive element 14 in the Y direction is within the range of the power supply line 12, which will be explained later.

[0036] Furthermore, antenna 1 has a first via 16 and a second via 18. As shown in Figures 2 and 3, the first via 16 penetrates the dielectric layer 2 and is connected to the first antenna element 8 and the feed line 12 on the second surface 2b side. The second via 18 penetrates the dielectric layer 2 and is connected to the second antenna element 10 and the feed line 12 on the second surface 2b side. In this embodiment, a via refers to a hole that penetrates the dielectric layer 2 and has conductivity due to a conductive metal plating layer or the like being provided on its inner surface, or a conductive metal being filled inside. Via 16 and Via 28 will be explained later.

[0037] [Regarding power supply lines] Figure 4 is an enlarged view of the main part of the second surface 2b. As shown in Figure 4, the second grounding conductor portion 6 on the second surface 2b has a slit 6b. The slit 6b extends from the edge portion 6a in the direction of X1. The second grounding conductor portion 6 is not provided in the inner portion of the slit 6b on the second surface 2b. Therefore, the inner portion of the slit 6b on the second surface 2b is part of the fourth region 2b2.

[0038] Multiple vias 20 are provided on both sides of the slit 6b in the Y direction. Multiple vias 20 penetrate the dielectric layer 2 and connect to the second ground conductor section 6 and the first ground conductor section 4. Thus, the multiple vias 20 connect the second ground conductor section 6 and the first ground conductor section 4. The multiple vias 20 are arranged in a line along the slit 6b.

[0039] In this embodiment, the connection between via 20 and the first ground conductor 4 means that via 20 and the first ground conductor 4 are electrically connected. Electrical connection between via 20 and the first ground conductor 4 includes not only direct contact between via 20 and the first ground conductor 4 or conductivity via other conductors, but also high-frequency connection through capacitive coupling between via 20 and the first ground conductor 4. The same applies to "connection" between conductors in the following description.

[0040] In Figure 4, the power supply line 12 is a conductor pattern made of copper or the like, mounted in the fourth region 2b2 of the second surface 2b. The power supply line 12 extends along the X direction. The power supply line 12 passes through the slit 6b and is provided to protrude from the edge 6a toward the X2 direction. The power supply line 12 includes a first line section 22 and a second line section 24. The first line section 22 is the portion of the power supply line 12 located outside the slit 6b (on the X2 side of the edge 6a).

[0041] The second line section 24 is the portion of the power supply line 12 located within the slit 6b. A small gap is provided between both edges of the second line section 24 in the Y direction and the end edges of the second grounding conductor section 6 in the slit 6b. The second line section 24, together with the second grounding conductor sections 6 located on both sides of the second line section 24, constitutes a coplanar line. The second line section 24 has a power supply point 25. The power supply point 25 is provided at the end of the second line section 24 on the X1 direction side. A signal source S, such as a communication module for wireless LAN communication, is connected to the power supply point 25. Furthermore, the second line section 24 has a thin wire section 24a and a thick wire section 24b. The power supply point 25 is provided in the thick wire section 24b. The thin wire section 24a is provided between the first line section 22 and the thick wire section 24b. Thus, the second line section 24 connects the power supply point 25 and the first line section 22.

[0042] The first track section 22 includes a track body 26, a pair of first stubs 28, and a pair of second stubs 30. The track body 26 has a rectangular shape. The track width (width in the Y direction) of the track body 26 (first track section 22) is wider than the width of the slit 6b. Therefore, the track width of the track body 26 is wider than the track width of the second track section 24. The track body 26 has a base edge 26f. The base edge 26f is the edge of the track body 26 on the X1 direction side. The base edge 26f is parallel to the Y direction. A small gap is provided between the base edge 26f and the edge 6a. The second track section 24 is connected to the base edge 26f. The second track section 24 is connected to the center of the base edge 26f.

[0043] The dashed lines in Figure 4 show the outlines of the first antenna element 8, the second antenna element 10, and the passive element 14 on the first surface 2a side when the dielectric layer 2 is viewed from the front in the Z1 direction. As shown in Figure 4, the track width of the main track 26 is wider than the track width (width in the X direction) of the first antenna element body 8a of the first antenna element 8. Also, the track width of the main track 26 is wider than the track width (width in the Y direction) of the short-circuit conductor portion 8b of the first antenna element 8. Furthermore, the track width of the main track 26 is wider than the track width (width in the X direction) of the second antenna element 10.

[0044] The transmission line body 26 has a first intersection 26a and a second intersection 26b. The first intersection 26a is a part of the transmission line body 26 that intersects the first antenna element 8 when the dielectric layer 2 is viewed from the front in the Z1 direction. The second intersection 26b is a part of the transmission line body 26 that intersects the second antenna element 10 when the dielectric layer 2 is viewed from the front in the Z1 direction. Furthermore, the main body of the track 26 has an overlapping portion 26e that overlaps with the short-circuit conductor portion 8b when viewed from the front of the dielectric layer 2.

[0045] A first via 16 is connected to the first intersection 26a. The first via 16 is connected to the center of the track width of the track body 26 at the first intersection 26a. The first via 16 penetrates the dielectric layer 2 and is connected to the first intersection 26a and to the portion of the first antenna element 8 corresponding to the first intersection 26a. Thus, the first via 16 connects the track body 26 and the first antenna element 8.

[0046] A second via 18 is connected to the second intersection 26b. The second via 18 is connected to the center of the track width of the track body 26 at the second intersection 26b. The second via 18 penetrates the dielectric layer 2 and is connected to the second intersection 26b and to the portion of the second antenna element 10 corresponding to the second intersection 26b. Thus, the second via 18 connects the track body 26 and the second antenna element 10.

[0047] A pair of first stubs 28 protrude from both side edges 26c of the track body 26. The pair of first stubs 28 extend rectangularly from both sides in the Y direction of the first intersection 26a. The pair of first stubs 28 protrude from the side edges 26c with the same dimensions to each other. As shown in Figure 4, the pair of first stubs 28 extend along the first antenna element 8 from both sides in the Y direction of the first intersection 26a in a front view of the dielectric layer 2. Furthermore, the width of the pair of first stubs 28 in the X direction is the same as the width of the line of the first antenna element body 8a. Therefore, in Figure 4, the X-direction side edges of the first stubs 28 extending from the line body 26 toward the Y1 direction coincide with the X-direction side edges of the first antenna element body 8a. The first stub 28, which extends from the main track body 26 toward the Y2 direction, overlaps with the short-circuit conductor section 8b.

[0048] The pair of second stubs 30, like the pair of first stubs 28, protrude from both side edges 26c of the track body 26. The pair of second stubs 30 extend rectangularly from both sides in the Y direction of the second intersection 26b. The pair of second stubs 30 protrude from the side edges 26c with the same dimensions to each other. As shown in Figure 4, the pair of second stubs 30 extend along the second antenna element 10 from both sides in the Y direction of the second intersection 26b in a front view of the dielectric layer 2. Furthermore, the width of the pair of second stubs 30 in the X direction is the same as the line width of the second antenna element 10. Therefore, in Figure 4, the X-direction side edges of the pair of second stubs 30 coincide with the X-direction side edges of the second antenna element 10. Furthermore, the edges of the pair of second stubs 30 on the X2 direction side and the leading edge 26d of the track body 26 are connected in a straight line. The leading edge 26d coincides with the edge of the second antenna element 10 on the X2 direction side.

[0049] As described above, the power supply line 12 is connected to the first antenna element 8 and the second antenna element 10 via the first via 16 and the second via 18. Therefore, the first antenna element 8 is powered from the signal source S via the feed line 12 and the first via 16. Here, the first element end 8a1 of the first antenna element body 8a is an open end. The second element end 8a2 is short-circuited by the short-circuit conductor portion 8b. The first via 16 is connected between the two element ends 8a1 and 8a2 of the first antenna element body 8a. Therefore, the first antenna element 8 constitutes an inverted F-type antenna. An inverted F antenna is an antenna that comprises an antenna element, a feed line connected to the antenna element, and a short-circuit line for grounding the antenna element, and whose input impedance can be adjusted by the distance between the feed line and the short-circuit line.

[0050] Furthermore, the second antenna element 10 is powered from the signal source S via the feed line 12 and the second via 18. Here, the second via 18 is connected between the two element ends 10a and 10b of the second antenna element 10. Also, the third element end 10a, which is the end of the second antenna element 10 (second antenna element body 10c), is an open end. Therefore, the second antenna element 10 (second antenna element body 10c), together with the feed line 12 and the second via 18, constitutes an inverted L-shaped antenna. An inverted L-shaped antenna is an antenna constructed by bending the antenna element of a monopole antenna at a right angle in the middle of the element.

[0051] In this embodiment, the second antenna element 10 is shown to have a stub portion 10d in addition to the second antenna element body 10c. This stub portion 10d functions as a stub provided on an inverted L-shaped antenna. Therefore, although this embodiment illustrates a case where an inverted F-type antenna, which includes a second antenna element 10, has a stub portion 10d, it is also possible to have a configuration without a stub portion 10d.

[0052] In the antenna 1 described above, the first antenna element 8 and the second antenna element 10 enable the transmission and reception of signals in two frequency bands, the first frequency band and the second frequency band.

[0053] According to this embodiment, since the feed line 12 has a first line section 22 (line body 26) having a line width wider than the width of the first antenna element 8, the VSWR in the first frequency band targeted by the first antenna element 8 can be reduced over a wide range. As a result, good VSWR characteristics can be obtained. In particular, in this embodiment, the VSWR characteristics in the first frequency band targeted by the first antenna element 8 can be changed without significantly changing the VSWR characteristics in the second frequency band targeted by the second antenna element 10.

[0054] In a multiband antenna with two antenna elements, adjusting the characteristics of one antenna element may change the characteristics of the other antenna element. Therefore, it can sometimes be difficult to properly set the characteristics of both antenna elements.

[0055] In this embodiment, by adjusting the width of the first transmission line 22 within a range wider than the width of the first antenna element 8, the VSWR characteristics in the first frequency band targeted by the first antenna element 8 can be changed without significantly altering the VSWR characteristics in the second frequency band targeted by the second antenna element 10. As a result, the VSWR characteristics in the first frequency band can be selectively improved. Therefore, it becomes easy to individually set the VSWR characteristics of both antenna elements 8 and 10, and the characteristics of both antenna elements 8 and 10 can be appropriately set.

[0056] Furthermore, in this embodiment, the power supply line 12 includes a second line section 24 connecting the power supply point 25 and the first line section 22, and this second line section 24 is narrower than the line width of the first line section 22. Therefore, only the necessary portion of the power supply line 12 can be made wider than the width of the first antenna element 8.

[0057] In this embodiment, the power supply line 12 comprises a line body 26 having a first intersection 26a and a second intersection 26b, a pair of first stubs 28 extending along the first antenna element 8 from both sides of the first intersection 26a, and a pair of second stubs 30 extending along the second antenna element 10 from both sides of the second intersection 26b. In this case, the VSWR characteristics of the first frequency band can be changed without significantly altering the VSWR characteristics of the second frequency band, thereby effectively improving the VSWR characteristics of the first frequency band.

[0058] Furthermore, the antenna 1 of this embodiment includes a linear parasitic element 14 provided at a predetermined distance from the side opposite to the side on which the second antenna element 10 is provided, on both sides of the first antenna element 8. This allows the VSWR characteristics of the first frequency band to be changed without significantly altering the VSWR characteristics of the second frequency band, thereby more effectively improving the VSWR characteristics of the first frequency band.

[0059] [Regarding other embodiments] Figure 5 is a plan view showing the main parts of the antenna 1 according to the second embodiment. The antenna 1 of this embodiment differs from the first embodiment in that it does not have a pair of first stubs 28, a pair of second stubs 30, and a parasitic element 14. Other aspects are the same as in the first embodiment. In the second embodiment as well, since the feed line 12 has a first line section 22 (line body 26) having a line width wider than the width of the first antenna element 8, the VSWR in the first frequency band targeted by the first antenna element 8 can be reduced over a wider range.

[0060] Figure 6 is a plan view showing the main parts of the antenna 1 according to the third embodiment. The antenna 1 of this embodiment differs from the first embodiment in that it does not have a pair of first stubs 28 and a parasitic element 14. Other aspects are the same as in the first embodiment. In the third embodiment as well, since the feed line 12 has a first line section 22, the VSWR in the first frequency band targeted by the first antenna element 8 can be reduced over a wider range. Furthermore, this embodiment includes a pair of second stubs 30 extending from the main line body 26 along the second antenna element 10. This allows for effective improvement of the VSWR characteristics in the first frequency band.

[0061] Figure 7 is a plan view showing the main parts of the antenna 1 according to the fourth embodiment. The antenna 1 of this embodiment differs from that of the first embodiment in that it does not have a parasitic element 14. Other aspects are the same as in the first embodiment. In the fourth embodiment as well, since the feed line 12 has a first line section 22, the VSWR in the first frequency band targeted by the first antenna element 8 can be reduced over a wider range. Furthermore, this embodiment includes a pair of first stubs 28 extending from the main line 26 along the first antenna element 8, and a pair of second stubs 30 extending along the second antenna element 10. This allows for effective improvement of the VSWR characteristics in the first frequency band.

[0062] Figure 8 is a plan view showing the main parts of the antenna 1 according to the fifth embodiment. The antenna 1 of this embodiment differs from the first embodiment in that it does not have a second antenna element 10, a passive element 14, and a pair of second stubs 30. Since the antenna 1 of this embodiment does not have a second antenna element 10, it is possible to transmit and receive signals only in the first frequency band.

[0063] In this embodiment, since there is no second antenna element 10, the length of the transmission line body 26 in the X direction is shorter than in the first embodiment. The edges of the pair of first stubs 28 on the X2 direction side and the leading edge 26d of the track body 26 are connected in a straight line. The leading edge 26d coincides with the edge of the first antenna element 8 on the X2 direction side.

[0064] In this embodiment as well, since the feed line 12 has a first line section 22 with a line width wider than the width of the first antenna element 8, the VSWR in the first frequency band targeted by the first antenna element 8 can be reduced over a wider range. As a result, good VSWR characteristics can be obtained.

[0065] In the fifth embodiment, a case with a pair of first stubs 28 was shown, but a configuration without this pair of first stubs 28 is also possible.

[0066] 〔others〕 In the embodiments described above, we showed cases where the power supply line 12 has a pair of first stubs 28 and a pair of second stubs 30, as well as cases where it has no stubs and cases where it has only a pair of second stubs 30. However, it is also possible to have a configuration that has a pair of first stubs 28 and no pair of second stubs 30. In this case as well, the same effects can be obtained.

[0067] Furthermore, the antenna of this embodiment of the disclosure, viewed from another perspective, Dielectric layer and A linear first antenna element provided on the first surface of the dielectric layer and having an electrical length corresponding to a first frequency band, A linear second antenna element provided on the first surface of the dielectric layer and having an electrical length corresponding to a second frequency band lower than the first frequency band, A power supply line having a power supply point is provided on the second surface of the dielectric layer opposite to the first surface, A first via penetrates the dielectric layer and is connected to the first antenna element and the feed line, A second via penetrates the dielectric layer and is connected to the second antenna element and the feed line, It is equipped with.

[0068] This configuration includes a first via connected to the first antenna element and a second via connected to the second antenna element, allowing each of the two antenna elements to be directly supplied with power from the feed line. As a result, power is not supplied to the other antenna element via one antenna element, making it easy to individually set the characteristics of both antenna elements.

[0069] [Regarding verification tests] Next, we will explain the verification tests conducted regarding the effects of Antenna 1. As part of the testing method, a model of antenna 1 according to each of the above embodiments was constructed, and the frequency characteristics of the VSWR of antenna 1 were determined by computer simulation using this model. The first frequency band targeted by the first antenna element was set to the range from 5 GHz to 6 GHz, and the second frequency band targeted by the second antenna element was set to the range from 2.4 GHz to 2.5 GHz. The VSWR in these frequency bands was evaluated.

[0070] Figure 9 is a diagram illustrating the dimensions of each part of the model of the antenna 1 according to the first embodiment, and shows the dimensions of the feed line 12. Figure 10 is a diagram illustrating the dimensions of each part of the model of the antenna 1 according to the first embodiment, and shows the dimensions of the first antenna element 8, the second antenna element 10, and the passive element 14. Note that Figure 10 shows the view from the Z1 direction.

[0071] In Figure 9, the dimensions of each part of the power supply line 12 were set as follows. Dimension of dielectric layer 2 in the Y direction: 60 mm Dimension of dielectric layer 2 in the X direction: 50 mm Track body 26, track width W1: 4.7mm Track width W2 of thin line section 24a (second track section 24): 0.4 mm Thick line section 24b (second track section 24) track width W3: 0.7mm Slit 6b width W4: 0.96mm Diameter of via 16, via 28, and via 20: 0.3 mm Via 20 pitch P: 1mm Track gauge W5: 1mm for stub 28 (first stub) Track width W6:1mm for the second stub 30 The distance L3 between the first stub 28 and the second stub 30 is 1.1 mm. The distance L1 between the tips of the pair of first stubs 28 is 10.4 mm. The distance L2 between the tips of the pair of second stubs 30 is 6.7 mm. Length L4 from the pair of first stubs 28 to the base edge 26f of the track body 26: 3.1 mm Length L5 from base edge 26f to edge 6a: 0.3 mm Length L6 from edge 6a to the tip of thick line section 24b (second track section 24): 10 mm Length L7 from the boundary between the thin line section 24a and the thick line section 24b to the edge 6a: 4 mm Width in the X direction of area 4, 2b2: W8:9mm

[0072] In Figure 10, the dimensions of each part of each element were set as follows. Width of the first antenna element body 8a W10: 1mm Second antenna element 10 width W11: 1mm Width of powerless element 14 W12: 1mm The distance W13 between the first antenna element 8 and the second antenna element 10 is 1.1 mm. The distance W14 between the first antenna element body 8a and the unpowered element 14 is 0.7 mm. Distance W15 from the unpowered element 14 to the edge 4a: 1.7 mm The dimension L10 from the edge of the first element end 8a1 of the first antenna element 8 to the center line C is 6.3 mm. The center line C is a straight line parallel to the X direction that passes through the centers of via 20, the first via 16, and the second via 18, which are aligned in the Y direction. Dimension L11 from the center line C to the edge of the short-circuit conductor section 8b on the Y2 direction side: 6.1 mm The dimension L12 from the edge of the third element end 10a of the second antenna element 10 to the center line C is 15.8 mm. The dimension L13 from the center line C to the edge of the fourth element end 10b of the second antenna element 10 is 7.2 mm. Dimension L14 from edge 4a to edge of short-circuit conductor 8b on the X2 direction side: 4.4 mm The dimension L15 in the Y direction from the edge of the fifth element end 14a of the unpowered element 14 to the edge of the first element end 8a1 is 6.1 mm. The dimension L16 in the Y direction from the edge of the first element end 8a1 to the edge of the sixth element end 14b of the unpowered element 14 is 6.4 mm. Width W16 in the Y direction of the short-circuit conductor section 8b: 4 mm The distance W17 between the edge of the short-circuit conductor section 8b on the Y1 direction and the center line C is 2.1 mm.

[0073] Furthermore, the thickness of dielectric layer 2 was set to 1.462 mm, the relative permittivity of dielectric layer 2 to 4.355, and the dielectric loss tangent to 0.0157. The conductor patterns mounted on the dielectric layer 2, such as the first antenna element 8, the first ground conductor section 4, and the second ground conductor section 6, are made of copper foil with a thickness of 0.036 mm.

[0074] The dimensions of the models according to other embodiments were set in accordance with the dimensions of the antenna 1 model according to the first embodiment described above.

[0075] • Influence of track width on the first track section 22 Using the antenna 1 model of the second embodiment, we investigated the effect of the track width of the first track section 22 (track body 26) on the VSWR. The dimensions of the antenna 1 model in the second embodiment are the same as those of the antenna 1 model in the first embodiment, except that the first stub 28, the second stub 30, and the passive element 14 are absent, and the track width W1 of the track body 26 is variable. Comparative Example 1 and Examples 1 through 4 below were used. Comparative Example 1: The track width W1 of the main track body 26 was set to 1 mm (the same as the width W10 of the first antenna element 8). Example 1: The track width W1 of the track body 26 was set to 2 mm. Example 2: The track width W1 of the track body 26 was set to 3 mm. Example 3: The track width W1 of the track body 26 was set to 4 mm. Example 4: The track width W1 of the track body 26 was set to 5 mm.

[0076] Figure 11 is a Smith chart plotting the input impedance at the power supply points of Comparative Example 1 and Examples 1 to 4. The markers m1 to m10, indicated by points in Figure 11, represent the following impedances. Marker m1: Impedance of Comparative Example 1 at a frequency of 2.45 GHz Marker m2: Impedance of Example 1 at a frequency of 2.45 GHz Marker m3: Impedance of Example 2 at a frequency of 2.45 GHz Marker m4: Impedance of Example 3 at a frequency of 2.45 GHz Marker m5: Impedance of Example 4 at a frequency of 2.45 GHz Marker m6: Impedance of Comparative Example 1 at a frequency of 5.5 GHz Marker m7: Impedance of Example 1 at a frequency of 5.5 GHz Marker m8: Impedance of Example 2 at a frequency of 5.5 GHz Marker m9: Impedance of Example 3 at a frequency of 5.5 GHz Marker m10: Impedance of Example 4 at a frequency of 5.5 GHz

[0077] The diagrams in Figure 11 show that at a frequency of 2.45 GHz, the reflection coefficient of Example 1 is the lowest, and that the reflection coefficient increases with increasing line width W1. Furthermore, the diagrams in Figure 11 show that at a frequency of 5.5 GHz, the reflection coefficient of Comparative Example 1 is the largest when the line width W1 of the line body 26 is increased, and the reflection coefficient decreases as the line width W1 increases. Furthermore, Figure 11 shows that the change in impedance with respect to the change in line width W1 at a frequency of 5.5 GHz is more significant than the change in impedance with respect to the change in line width W1 at a frequency of 2.45 GHz.

[0078] Figure 12 shows the frequency characteristics of the VSWR for Comparative Example 1 and Examples 1 to 4. In Figure 12, the vertical axis represents the VSWR, and the horizontal axis represents the signal frequency. As shown in Figure 12, Comparative Example 1 does not exhibit good characteristics in both the first frequency band (5 GHz to 6 GHz) and the second frequency band (2.4 GHz to 2.5 GHz). In particular, in the first frequency band, the VSWR never falls below 2.0, which is a practical value. On the other hand, in Examples 1 to 4, an improvement in VSWR is observed compared to Comparative Example 1. In particular, when comparing Examples 1 to 4 with each other, no significant differences are observed in the second frequency band. However, in the first frequency band, the VSWR decreases significantly with increasing line width W1.

[0079] From these results, it can be seen that by having a first transmission line section 22 with a transmission line width W1 that is wider than the width W10 of the first antenna element 8, the VSWR in the first frequency band can be reduced over a wide range.

[0080] Furthermore, when the track width W1 is changed, there is no significant change in the VSWR of the second frequency band, while there is a significant change in the VSWR of the first frequency band. From these results, we can see that the track width W 1 It can be seen that by making adjustments, the VSWR characteristics in the first frequency band can be changed without significantly altering the VSWR characteristics in the second frequency band.

[0081] • Influence of the second stub 30 Using the antenna 1 model of the third embodiment, the effect of the pair of second stubs 30 on VSWR was investigated. The dimensions of the antenna 1 model in the third embodiment are the same as those of the antenna 1 model in the first embodiment, except that the first stub 28 and the passive element 14 are absent, and the track width W1 of the track body 26 is the same. The following Example 5 was used. Example 5: The track width W1 of the track body 26 was set to 5 mm.

[0082] In other words, Example 4 and Example 5 differ only in the presence or absence of a pair of second stubs 30. By comparing Example 4 and Example 5, the effect of the pair of second stubs 30 was examined.

[0083] Figure 13 is a Smith chart plotting the input impedance at the feed point of Example 5. In Figure 13, the impedance of Example 5 is shown by a solid line. The impedance of Example 4 is shown by a dashed line. Marker m11 shows the impedance of Example 5 at a frequency of 2.45 GHz, and marker m12 shows the impedance of Example 5 at a frequency of 5.5 GHz. In Figure 13, looking at the frequency around 2.45 GHz, no significant change is observed between Example 5 and Example 4. On the other hand, when we zoom in on the portion of Figure 13 enclosed by circle E, which corresponds to frequencies above 5.5 GHz, the change between Example 5 and Example 4 is more pronounced than in the case around 2.45 GHz.

[0084] Figure 14 shows the frequency characteristics of the VSWR for Example 5. In Figure 14, the vertical axis represents the VSWR, and the horizontal axis represents the signal frequency. In Figure 14, the VSWR for Example 5 is shown by a solid line, and the VSWR for Example 4 is shown by a dashed line. In Figure 14, as in Figure 13, the change between Example 5 and Example 4 is almost invisible in the second frequency band, but slightly visible in the first frequency band.

[0085] From this, it can be seen that the addition of the second stub 30 causes a change in VSWR in the first frequency band more than in the second frequency band. As a result, it can be seen that by providing a second stub 30 along the second antenna element 10, the VSWR characteristics of the first antenna element 8 in the first frequency band can be changed without significantly changing the VSWR characteristics in the second frequency band.

[0086] • Influence of the first stub 28 Using the antenna 1 model of the fourth embodiment, the effect of the pair of first stubs 28 on VSWR was investigated. The dimensions of the antenna 1 model in the fourth embodiment are the same as those of the antenna 1 model in the first embodiment, except that the passive element 14 is absent and the track width W1 of the track body 26 is the same. The following Example 6 was used. Example 6: The track width W1 of the track body 26 was set to 5 mm.

[0087] In other words, Example 5 and Example 6 differ only in the presence or absence of a pair of first stubs 28. By comparing Example 5 and Example 6, the effect of the pair of first stubs 28 was examined.

[0088] Figure 15 is a Smith chart plotting the input impedance at the feed point of Example 6. Marker m13 shows the impedance at a frequency of 2.45 GHz, and marker m14 shows the impedance at a frequency of 5.5 GHz. In Figure 15, looking at the frequency around 2.45 GHz, no significant change is observed between Example 6 and Example 5. On the other hand, looking at the frequency around 5.5 GHz in Figure 15, the shape of the diagram has changed significantly compared to Example 5, indicating that the impedance has changed considerably between Example 6 and Example 5.

[0089] Figure 16 shows the frequency characteristics of the VSWR in Example 6. In Figure 16, the vertical axis represents the VSWR, and the horizontal axis represents the signal frequency. In Figure 16, as in Figure 15, there is almost no change between Example 6 and Example 5 in the second frequency band, but a slight change is observed in the first frequency band.

[0090] From this, it can be seen that the addition of the first stub 28 causes a change in VSWR in the first frequency band more than in the second frequency band. As a result, it can be seen that by providing the first stub 28, the VSWR characteristics of the first frequency band can be changed without significantly altering the VSWR characteristics in the second frequency band.

[0091] • Influence of the unpowered element 14 Using the antenna 1 model of the first embodiment, we investigated the effect of the parasitic element 14 on VSWR. The dimensions of the antenna 1 model in the first embodiment are as described above. The antenna 1 model from the first embodiment was used as Example 7.

[0092] Examples 6 and 7 differ slightly in the track width W1, but also in the presence or absence of the passive power element 14. Therefore, the effect of the passive power element 14 was investigated by comparing Examples 6 and 7.

[0093] Figure 17 is a Smith chart plotting the input impedance at the feed point of Example 7. Marker m15 shows the impedance at a frequency of 2.45 GHz, and marker m16 shows the impedance at a frequency of 5.5 GHz. In Figure 17, looking at the frequency around 2.45 GHz, no significant change is observed between Example 7 and Example 6. On the other hand, looking at the frequency around 5.5 GHz in Figure 17, the shape of the diagram changes significantly compared to Example 6, indicating that the impedance changes significantly between Example 7 and Example 6.

[0094] Figure 18 shows the frequency characteristics of the VSWR in Example 7. In Figure 18, the vertical axis represents the VSWR, and the horizontal axis represents the signal frequency. In Figure 18, as in Figure 17, there is almost no change between Example 7 and Example 6 in the second frequency band, but a change is observed in the first frequency band. In the first frequency band shown in Figure 18, the VSWR is below 1.5 across the entire range. Therefore, the VSWR is even lower than the practical VSWR value of 2.0, and according to Example 7, higher requirements for communication quality can be met.

[0095] From the above, it can be seen that the addition of the powerless element 14 causes a change in VSWR in the first frequency band more than in the second frequency band. As a result, it can be seen that by providing the unpowered element 14, the VSWR characteristics of the first frequency band can be changed without significantly altering the VSWR characteristics in the second frequency band.

[0096] [Conclusion] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims, not in the sense described above, and is intended to include the meaning and scope of equivalents of the claims, and all modifications within that scope. [Explanation of symbols]

[0097] 1 Antenna 2 Dielectric layers 2a 1st page 2a1 1st area 2a2 2nd area 2b 2nd side 2b1 Third area 2b2 4th area 4. First grounding conductor section 4a Edge 6. Second grounding conductor section 6a Edge 6b Slit 8. First antenna element 8a First antenna element body 8a1 End of first element 8a2 Second element end 8a3 side edge 8b Short-circuit conductor section 8b1 Side 8b2 Tip edge 10. Second antenna element 10a Third element end 10b End of the 4th element 10c Second antenna element body 10d Stub section 12 Power supply lines 14. Powerless element 14a End of fifth element 14b End of element 6 16. First Beer 18. Second Beer 20 Beer 22. First track section 24 Second track section 24a Fine line part 24b Thick line section 25 Power supply point 26. Main track section 26a First intersection 26b Second intersection 26c side edge 26d tip edge 26e Overlapping part 26f proximal edge 28 First stub 30 Second stub S signal source

Claims

1. Dielectric layer and A linear first antenna element provided on the first surface of the dielectric layer, A power supply line having a power supply point is provided on the second surface opposite to the first surface of the dielectric layer, The device comprises a first via that penetrates the dielectric layer and is connected to the first antenna element and the power supply line, The power supply line includes a first line section to which the first via is connected. The width of the first line section is wider than the width of the first antenna element. antenna.

2. The power supply line further includes a second line section connecting the power supply point and the first line section. The second track section is narrower than the track width of the first track section. The antenna according to claim 1.

3. The aforementioned power supply line is A line body having an intersection portion that intersects the first antenna element in a front view of the dielectric layer, The antenna element comprises a pair of first stubs extending from both sides of the intersection along the first antenna element. The antenna according to claim 1 or claim 2.

4. The system further comprises a linear parasitic element that extends along the longitudinal direction of the first antenna element and is provided on the first surface at a predetermined distance from the first antenna element. The antenna according to claim 1 or claim 2.

5. The first antenna element has an electrical length corresponding to the first frequency band. The aforementioned antenna is A linear second antenna element extends along the longitudinal direction of the first antenna element and is provided on the first surface at a predetermined distance from the first antenna element, and has an electrical length corresponding to a second frequency band lower than the first frequency band, The system further comprises a second via that penetrates the dielectric layer and is connected to the second antenna element and the feed line. The antenna according to claim 1.

6. The second antenna element is provided at a predetermined distance from the side of the first antenna element opposite to the side on which the grounding conductor portion is provided. The antenna according to claim 5.

7. The aforementioned power supply line is A line body having a first intersection portion that intersects the first antenna element in a front view of the dielectric layer, A pair of first stubs extending from both sides of the first intersection along the first antenna element, Equipped with The antenna according to claim 5.

8. The aforementioned power supply line is A line body having a second intersection that intersects the second antenna element in a front view of the dielectric layer, A pair of second stubs extending from both sides of the second intersection along the second antenna element, Equipped with The antenna according to claim 5.

9. The first antenna element further comprises a linear parasitic element provided on the first surface at a predetermined distance from the side opposite to the side facing the second antenna element. The antenna according to claim 5.

10. The first antenna element constitutes an inverted F-type antenna. The aforementioned second antenna element constitutes an inverted L-shaped antenna. The antenna according to any one of claims 5 to 9.

11. The first antenna element is, The antenna element body to which the first via is connected, It includes a grounding conductor portion arranged in parallel with the antenna element body and a short-circuiting conductor portion connecting one end of the antenna element body, The track width of the first track section is wider than the track width of the short-circuit conductor section. The antenna according to claim 1.

12. The first line portion has an overlapping portion that overlaps with the short-circuit conductor portion when viewed from the front of the dielectric layer. The antenna according to claim 11.

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