Antenna device and wireless communication device

Abstract

To provide an antenna device in which antennas adjacent to each other are enabled to mutually improve antenna characteristics even in a case where antenna power feeding is separately performed to the antennas adjacent to each other, and a radio communication apparatus.SOLUTION: An antenna device comprises a first antenna 10, which is a tip short type antenna being operated in a first frequency f1, and a second antenna 20 which is disposed in proximity to the first antenna 10. The second antenna 20 is operated in a second frequency f2, which is a lower frequency than the first frequency f1, and the second antenna 20 includes a power feeding point at the side of a tip short part 11 in the first antenna 10. In the second antenna 20, an end portion 22 at an opposite side of the side of the tip short part 11 in the first antenna 10 is open, and the second antenna 20 has a substantially 1 / 2 length as long as a wavelength of λ1 of the first frequency f1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an antenna device and a wireless communication device. [Background technology]

[0002] Recent mobile terminals are equipped with various antennas. For example, Patent Document 1 discloses a technology for realizing a wideband antenna by using a first metal piece connected to a power feed point inside the frame and a second metal piece that is coupled to the first metal piece via a gap and receives power. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2021-524166 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, mobile terminals have been required to provide antennas for multiple systems, such as a 4G antenna, a GPS (Global Positioning System) antenna, a Bluetooth (registered trademark) antenna, a Wi-Fi (registered trademark) antenna, and a 5G antenna, etc. It is undesirable to connect multiple antennas used for different systems by capacitive coupling.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide an antenna device and a wireless communication device that enable adjacent antennas to mutually improve the antenna characteristics even when the adjacent antennas are fed with antenna power separately. [Means for solving the problem]

[0006] The antenna device and wireless communication device according to the present invention, which are intended to solve the above-mentioned problems, are as follows.

[0007] (1) That is, one aspect of the present invention is an antenna device comprising: a first antenna that is a short-tip antenna that operates at a first frequency f1; and a second antenna that is arranged in close proximity to the first antenna; the second antenna operates at a second frequency f2 that is lower than the first frequency f1; the second antenna has a feed point on the short-tip side of the first antenna; the end of the second antenna opposite to the short-tip side of the first antenna is open; and the second antenna has a length of approximately 1 / 2 the wavelength λ1 of the first frequency f1.

[0008] (2) Another aspect of the present invention is the antenna device described above, wherein the end of the second antenna opposite the end of the first antenna that is short-circuited at the tip is arranged on the second slit side, and the end of the first antenna opposite the end of the first antenna that is short-circuited at the tip is arranged on the third slit side.

[0009] (3) Furthermore, another aspect of the present invention is the antenna device described above, wherein a first filter that is a filter that provides low impedance at the second frequency f2 is provided in a power feeding section of the first antenna.

[0010] (4) Another aspect of the present invention is the antenna device described above, further comprising a second filter, which is a filter that exhibits high impedance at the first frequency f1, in a power feeding section of the second antenna.

[0011] (5) Another aspect of the present invention is the antenna device described above, wherein the second antenna is operable at a third frequency f3 that is different from the second frequency f2, and the power supply section of the first antenna is provided with a third filter that is a filter that becomes high impedance at the third frequency f3.

[0012] (6) Another aspect of the present invention is a wireless communication device including an antenna device, the antenna device including a first antenna that is a short-tip antenna that operates at a first frequency f1, and a second antenna arranged in close proximity to the first antenna, the second antenna operating at a second frequency f2 that is lower than the first frequency f1, the second antenna having a feed point on the short-tip side of the first antenna, the second antenna having an open end on the opposite side to the short-tip side of the first antenna, and the second antenna having a length of approximately 1 / 2 the wavelength λ1 of the first frequency f1. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide an antenna device and a wireless communication device that are capable of mutually improving the antenna characteristics of adjacent antennas even when adjacent antennas are fed with antenna power separately. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view showing an example of an antenna device and a wireless communication device according to a first embodiment. [Figure 2] FIG. 4 is a diagram illustrating the operation of the first antenna in the first embodiment. [Figure 3] FIG. 4 is a diagram illustrating the operation of the second antenna in the first embodiment. [Figure 4] FIG. 10 is a cross-sectional view showing an example of an antenna device and a wireless communication device according to a second embodiment. [Figure 5] FIG. 10 is a diagram illustrating the operation of the first antenna in the second embodiment. [Figure 6] FIG. 10 is a diagram illustrating the operation of the second antenna in the second embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing an example of an antenna device and a wireless communication device according to a third embodiment. [Figure 8] FIG. 10 is a diagram illustrating the operation of the second antenna in the third embodiment. [Figure 9] FIG. 10 is a diagram illustrating an example of a second filter. [Figure 10] FIG. 2 is a diagram illustrating an example of a first filter. [Figure 11] FIG. 10 is a diagram illustrating an example of a third filter. [Figure 12] FIG. 10 is a diagram illustrating an example of a combination of the third filter and the first filter. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described below based on preferred embodiments.

[0016] The antenna device and wireless communication device according to the embodiment can be used in mobile phone terminals, smartphones, tablet terminals, personal digital assistants, mobile PC terminals, etc., but is not limited to these.

[0017] (First embodiment) FIG. 1 illustrates a first embodiment of an antenna device 30 and a wireless communication device 100. As shown in FIG.

[0018] The wireless communication device 100 is a device that performs wireless communication using the antenna device 30. Although not particularly shown, the wireless communication device 100 may also include a display panel, a back panel, a metal frame, a circuit board, a recording medium, a battery, a cable, and the like.

[0019] Although not particularly shown, the antenna device 30 may be protected by being covered with an electrically insulating member. The electrically insulating member may be made of, for example, resin or other materials.

[0020] The antenna device 30 includes a first antenna 10 and a second antenna 20 arranged close to each other. The first antenna 10 is a short-ended antenna that operates at a first frequency f1. The second antenna 20 operates at a second frequency f2 that is lower than the first frequency f1.

[0021] In the following description, the first antenna 10 and the second antenna 20 may be collectively referred to simply as “antennas 10, 20.” The antennas 10, 20 may be a combination selected from a plurality of systems, such as a 4G antenna, a GPS antenna, a Bluetooth (registered trademark) antenna, a Wi-Fi (registered trademark) antenna, and a 5G antenna.

[0022] The first antenna 10 has a tip short-circuit portion 11. The tip short-circuit portion 11 is configured by arranging a short-circuit portion 15 on the tip side as viewed from the feed point 13 of the first antenna 10. Here, the role of the short-circuit portion 15 is to ground it to the GND of the wireless communication device 100. Of course, the short-circuit portion 15 may also be connected to the GND of the circuit board. The feed point 13 of the first antenna 10 is connected to the feed portion 14 of the first antenna 10. The first antenna 10 may be designed as an inverted-F antenna.

[0023] The first antenna 10 preferably has a length approximately half the wavelength λ1 of the first frequency f1. The first antenna 10 only needs to operate at a half wavelength (λ / 2) of the wavelength λ1. For example, the physical length L1 of the first antenna 10 may be approximately 3 / 8 to 5 / 8 times the wavelength λ1.

[0024] The first antenna 10 may have an end 12 on the opposite side to the tip short-circuiting portion 11. The opposite end 12 is arranged on the third slit 33 side with respect to the other metal member 40. In this case, the first antenna 10 has a physical length L1 between the tip short-circuiting portion 11 and the opposite end 12 that is approximately ½ of the wavelength λ1.

[0025] The first antenna 10 has an end 12 on the opposite side to the third slit 33, which has the advantages of facilitating matching adjustment of the first antenna 10 and making it easier to utilize harmonics, thereby facilitating antenna design. The third slit 33 is disposed at an end 41 of the other metal member 40 that is close to the first antenna 10.

[0026] The second antenna 20 is close to the first antenna 10 but is physically separated from the first antenna 10 by a first slit 31. The second antenna 20 has an end 21 on the tip short-circuit portion 11 side of the first antenna 10. The first slit 31 is disposed between the tip short-circuit portion 11 and the end 21 on the tip short-circuit portion 11 side.

[0027] The second antenna 20 has a feed point 23 on the tip short-circuit portion 11 side of the first antenna 10. The feed point 23 of the second antenna 20 is connected to a feed portion 24 of the second antenna 20. The end 22 of the second antenna 20 opposite the tip short-circuit portion 11 side is open. The second antenna 20 may be designed as an inverted L antenna.

[0028] The opposite end 22 is arranged on the second slit 32 side with respect to the other metal member 40. In this case, the second antenna 20 has a physical length L2 between the end 21 on the tip short-circuit portion 11 side and the opposite end 22. The second slit 32 is arranged at an end 42 of the other metal member 40 that is close to the second antenna 20.

[0029] The second antenna 20 has a length that is approximately half the wavelength λ1 of the first frequency f1. With this configuration, the two adjacent antennas 10, 20 can ensure good antenna performance.

[0030] The operation of the first antenna 10 will be described with reference to Fig. 2. As described above, the first antenna 10 is coupled to the second antenna 20 between the antennas 10,20.

[0031] By setting the physical length L2 of the second antenna 20, the second antenna 20 appears as an excited element having a length of approximately half the wavelength (λ1 / 2) with both ends open for the first frequency f1 (wavelength λ1) at which the first antenna 10 operates. The first antenna 10 and the second antenna 20 are antenna coupled in phase and constructively coupled with each other, improving the antenna performance of the first antenna 10.

[0032] The second antenna 20 may operate as a driven element with a half-wavelength (λ / 2) system with respect to the wavelength λ1. For example, the physical length L2 of the second antenna 20 may be from about 3 / 8 times to about 5 / 8 times the wavelength λ1.

[0033] Referring to FIG. 3, the operation of the second antenna 20 will be described. As described above, the second antenna 20 is coupled between the first antenna 10 and the antennas 10, 20. Also, since the second frequency f2 is lower than the first frequency f1, that is, f2 < f1, when converted to wavelengths respectively, the wavelength λ2 is longer than the wavelength λ1, that is, λ2 > λ1.

[0034] With respect to the wavelength λ2 of the second frequency f2 at which the second antenna 20 operates, the first antenna 10 appears to have both ends shorted and a physical length L1 shorter than half the wavelength (λ2 / 2) of λ2. At this time, with respect to the second antenna 20, the first antenna 10 appears to have both ends shorted, so-called as a ground wire, and its physical length is shorter than half the wavelength with respect to the wavelength λ2 of the second antenna 20. Therefore, the first antenna 10 does not interfere with the antenna radiation of the second antenna 20, and the second antenna 20 has good antenna performance.

[0035] Therefore, according to the antenna device 30, it is possible to provide a good antenna even in an antenna configuration where two antennas 10, 20 are adjacent to each other.

[0036] (Example 1) Next, regarding the first embodiment, Example 1 will be shown. The first antenna 10 is a Wi-Fi antenna (2.4 GHz band + 5 GHz band). The second antenna 20 is a GPS / 4G / 5G antenna (1.6 GHz band + 3.4 - 4.6 GHz band).

[0037] The first frequency f1 is set to 2.4 GHz. The physical length L1 of the first antenna 10 is set to approximately λ1 / 2. The first antenna 10 operates at 2.4 GHz as a λ / 2 inverted-F antenna and covers the 5 GHz band using the double wave of f1. The first antenna 10 operates as described with reference to FIG. 2.

[0038] The second frequency f2 is set to 1.6 GHz. The physical length L2 of the second antenna 20 is set to approximately λ1 / 2. The second antenna 20 operates at 1.6 GHz as a λ / 4 inverted-L antenna, and operates at 3.4 to 4.6 GHz using the tripled wave of the fundamental wave. The second antenna 20 operates as described with reference to FIG. 3.

[0039] Note that f2 is preferably 3 / 4 times or less than f1, and may be, for example, 1 / 2 to 3 / 4 times f1. Therefore, λ2 is preferably 4 / 3 times or more than λ1, and may be, for example, 4 / 3 to 2 times λ1.

[0040] (Second embodiment) FIG. 4 illustrates a second embodiment of the antenna device 30 and the wireless communication device 100. As shown in FIG.

[0041] In the second embodiment, the power supply unit 14 of the first antenna 10 includes a first filter 51 that is a filter that provides low impedance at the second frequency f2. The power supply unit 24 of the second antenna 20 includes a second filter 52 that is a filter that provides high impedance at the first frequency f1.

[0042] In the second embodiment, other configurations can be similar to those in the first embodiment, so the same or corresponding configurations are given the same reference numerals and redundant explanations may be omitted.

[0043] The first filter 51 and the second filter 52 may be configured by an LC circuit using, for example, an inductor (inductance L) and a capacitor (capacitance C).

[0044] An example of a filter that exhibits high impedance at a specific frequency is a notch filter. FIG. 9 illustrates a second filter 52 that is a notch filter exhibiting high impedance at a first frequency f1. The constants of the inductor L1 and the capacitor C1 can be selected to satisfy the equation f1 = 1 / (2π√(L1*C1)). Setting a large value for L1 allows adjustment to achieve a higher impedance at f1, thereby improving the antenna performance of the first antenna 10 coupled to the second antenna 20. However, setting a large value for L1 makes it difficult to adjust the antenna matching of the second antenna 20 around the frequency f1, resulting in antenna matching loss. Therefore, the constants of L1 and C1 can be appropriately selected in consideration of the balance between the antenna performance of the first antenna 10 and the second antenna 20.

[0045] Examples of filters that exhibit low impedance at specific frequencies include shunt filters and low-pass filters. FIG. 10 illustrates a first filter 51, which is a shunt filter exhibiting low impedance at a second frequency f2. The constants of the inductor L2 and the capacitor C2 can be selected to satisfy the equation f2 = 1 / (2π√(L2*C2)). Setting a small value for L2 allows adjustment to achieve a lower impedance at f2, thereby improving the antenna performance of the second antenna 20 coupled to the first antenna 10. However, setting a small value for L2 makes it difficult to adjust the antenna matching of the first antenna 10 around the frequency f2, resulting in antenna matching loss. Therefore, the constants of L2 and C2 can be appropriately selected, taking into consideration the balance of the antenna performance of the first antenna 10 and the second antenna 20.

[0046] The operation of the first antenna 10 in the second embodiment will be described with reference to Figure 5. By adding a second filter 52 to the power supply unit 24 of the second antenna 20, the connection between the second antenna 20 and the power supply unit 24 appears stable and open at the operating frequency f1 of the first antenna 10, regardless of the power supply connection status of the second antenna 20.

[0047] By adding the second filter 52, the physical length of the second antenna 20 becomes exactly λ½ and both ends are open-connected, which makes the second antenna 20 suitable for operating as the driven element of the first antenna 10.

[0048] The operation of the second antenna 20 in the second embodiment will be described with reference to Fig. 6. By adding the first filter 51 to the power supply unit 14 of the first antenna 10, the connection between the first antenna 10 and the power supply unit 14 appears to be almost short-circuited at the operating frequency f2 of the second antenna 20.

[0049] The addition of the first filter 51 keeps the physical length of the first antenna 10 shorter than λ / 2 and provides a short-circuited connection at both ends, making the first antenna 10 suitable for operating as a ground wire for the second antenna 20 and suitable for operation without interfering with the antenna radiation of the second antenna 20.

[0050] Therefore, according to the antenna device 30 of the second embodiment, even if the two antennas 10 and 20 shown in the first embodiment are adjacent to each other, it is possible to further improve performance in terms of providing a good antenna.

[0051] Example 2 Next, Example 2 will be described with respect to the second embodiment. The first antenna 10 is a Wi-Fi antenna (2.4 GHz band + 5 GHz band). The second antenna 20 is a GPS / 4G / 5G antenna (1.6 GHz band + 3.4 to 4.6 GHz band).

[0052] The first frequency f1 is set to 2.4 GHz. The physical length of the first antenna 10 is set to approximately λ1 / 2. The first antenna 10 operates at 2.4 GHz as a λ / 2 inverted-F antenna and covers the 5 GHz band by using the double wave of f1.

[0053] A second filter 52 that has high impedance at the first frequency f1 (2.4 GHz band) is provided at the power supply portion 24 of the second antenna 20. The first antenna 10 operates as described with reference to FIG.

[0054] The second frequency f2 is set to 1.6 GHz. The physical length of the second antenna 20 is set to approximately λ1 / 2. The second antenna 20 operates at 1.6 GHz as a λ / 4 inverted L antenna, and operates at 3.4 to 4.6 GHz using the tripled wave of the fundamental wave.

[0055] A first filter 51 that provides low impedance at the second frequency f2 (1.6 GHz band) is provided at the power supply portion 14 of the first antenna 10. The second antenna 20 operates as described with reference to FIG.

[0056] (Third embodiment) FIG. 7 illustrates a third embodiment of the antenna device 30 and the wireless communication device 100. As shown in FIG.

[0057] In the third embodiment, the second antenna 20 is operable at a third frequency f3 that is different from the second frequency f2. Furthermore, the power supply unit 14 of the first antenna 10 is provided with a third filter 53 that is a filter that exhibits high impedance at the third frequency f3.

[0058] In the third embodiment, other configurations can be similar to those in the first embodiment, so the same or corresponding configurations are given the same reference numerals and redundant explanations may be omitted.

[0059] The third filter 53 may be configured, for example, as an LC circuit using an inductor (inductance L) and a capacitor (capacitance C). Examples of filters that exhibit high impedance at a specific frequency include notch filters. FIG. 11 illustrates an example of the third filter 53, which is a notch filter that exhibits high impedance at a third frequency f3. The constants of the inductor L3 and the capacitor C3 may be selected to satisfy f3 = 1 / (2π√(L3*C3)). Increasing the value of L3 allows adjustment to achieve a higher impedance at f3, thereby improving the antenna performance of the second antenna 20 coupled to the first antenna 10. However, increasing the value of L3 makes it difficult to adjust the antenna matching of the first antenna 10 around the frequency f3, resulting in antenna matching loss. Therefore, the constants of L3 and C3 may be appropriately selected in consideration of the balance between the antenna performance of the first antenna 10 and the second antenna 20.

[0060] The first antenna 10 in the third embodiment operates as described in the first embodiment with reference to FIG.

[0061] Although not shown, similar to the second embodiment, the power supply unit 24 of the second antenna 20 in the third embodiment may be provided with a second filter 52 that exhibits high impedance at the first frequency f1. In this case, the first antenna 10 operates as described with reference to FIG. 5.

[0062] The operation of the second antenna 20 in the third embodiment will be described with reference to Figure 8. By adding the third filter 53 to the power supply 14 of the first antenna 10, the short-circuiting portion 15 of the first antenna 10 appears to be short-circuited and the power supply 14 appears to be open-circuited at the frequency f3 (wavelength λ3) of the second antenna 20. This makes it possible for the first antenna 10 to preferably function as a ground wire for the second antenna 20.

[0063] Example 3 Next, Example 3 will be described with respect to the third embodiment. The first antenna 10 is a Wi-Fi antenna (2.4 GHz band + 5 GHz band). The second antenna 20 is an antenna for GPS / 4G / 5G (1.6 GHz band + 3.4 to 4.6 GHz band).

[0064] The first frequency f1 is set to 2.4 GHz. The physical length of the first antenna 10 is set to approximately λ1 / 2. The first antenna 10 operates at 2.4 GHz as a λ / 2 inverted-F antenna and covers the 5 GHz band using the double wave of f1. The first antenna 10 operates as described with reference to FIG. 2.

[0065] When the second filter 52 that has high impedance at the first frequency f1 (2.4 GHz band) is provided in the power supply section 24 of the second antenna 20, the first antenna 10 operates as described with reference to FIG.

[0066] The second frequency f2 is set to 1.6 GHz. The third frequency f3 is set to 1.2 GHz. f3 is approximately half of f1, and the wavelength λ3 corresponding to the third frequency f3 is approximately twice λ1.

[0067] As described above, when f2 is 3 / 4 times or less than f1, f3 may be lower in frequency than f2. Just as f2 is lower in frequency than f1, f3 may be lower in frequency than f1.

[0068] The physical length of the second antenna 20 is set to approximately λ1 / 2. The second antenna 20 operates at 1.6 GHz as a λ / 4 inverted L antenna, and operates at 3.4 to 4.6 GHz using the triple wave of the fundamental wave.

[0069] The 1.6 GHz band frequency may be, for example, GPS L1 wave (1575.42 MHz), and the 1.2 GHz band frequency may be, for example, GPS L2 wave (1227.60 MHz) or L5 wave (1176.45 MHz).

[0070] A third filter 53 that has high impedance at f3 (1.2 GHz band) is provided in the power supply section 14 of the first antenna 10. This allows the second antenna 20 to operate as described with reference to FIG.

[0071] The physical length of the first antenna 10 is approximately λ1 / 2, so for a wavelength of λ3, the physical length is approximately λ3 / 4. One end is short-circuited at the tip short-circuit section 11. On the power supply section 14 side, the third filter 53 ensures that the other end is stably open-connected regardless of the power supply connection status of the first antenna 10. Therefore, at the operating frequency f3 of the second antenna 20, the first antenna 10 operates as a ground wire.

[0072] The first antenna 10 may operate in a 1 / 4 wavelength (λ / 4) system with respect to the wavelength λ3. For example, when the physical length of the first antenna 10 is approximately λ3 / 4, the first antenna 10 may have a length of approximately 1 / 8 to 3 / 8 times the wavelength λ3.

[0073] Although not specifically shown, the third filter 53 can also serve as the first filter 51. If the configuration of the third embodiment is used, a filter that becomes high impedance at the third frequency f3 (1.2 GHz) and low impedance at the second frequency f2 (1.6 GHz) may be provided in the power supply unit 14 of the first antenna 10. FIG. 12 illustrates an example in which the third filter 53, which is a notch filter that becomes high impedance at the third frequency f3, is combined with the first filter 51, which is a shunt filter that becomes low impedance at the second frequency f2. The constants of the inductor L2, the inductor L3, the capacitor C2, and the capacitor C3 may be selected as described above with reference to FIGS. 10 to 11 for the first filter 51 and the third filter 53.

[0074] This allows a stable open connection at the operating frequency f3 (1.2 GHz) of the second antenna 20, regardless of the power supply connection status of the first antenna 10. Furthermore, a stable short connection can be achieved at the operating frequency f2 (1.6 GHz) of the second antenna 20, regardless of the power supply connection status of the first antenna 10.

[0075] Although the present invention has been described above based on preferred embodiments, the present invention is not limited to the above-described embodiments and various modifications are possible without departing from the spirit of the present invention. Modifications include addition, substitution, omission, and other changes to components in each embodiment. Furthermore, components used in two or more embodiments can be combined as appropriate. [Explanation of symbols]

[0076] C1, C2, C3...capacitors, L1, L2, L3...inductors, L1...physical length of first antenna, L2...physical length of second antenna, 10...first antenna, 11...tip short-circuit portion, 12...end opposite to tip short-circuit portion, 13...feed point of first antenna, 14...feed portion of first antenna, 15...short-circuit portion, 20...second antenna, 21...end on the tip short-circuit portion side, 22...end opposite to tip short-circuit portion side, 23...feed point of second antenna, 24...feed portion of second antenna, 30...antenna device, 31...first slit, 32...second slit, 33...third slit, 40...other metal member, 41...end close to first antenna, 42...end close to second antenna, 51...first filter, 52...second filter, 53...third filter, 100...wireless communication equipment.

Claims

1. First frequency f １ a first antenna that is a short-ended antenna operating at a second antenna disposed adjacent to the first antenna; The second antenna transmits the first frequency f １ a second frequency f that is lower than ２ Works with the second antenna has a feeding point on the side of the tip short-circuit portion of the first antenna, The second antenna has an open end on the opposite side to the tip short-circuit portion of the first antenna, The second antenna transmits the first frequency f １ Wavelength λ １ The antenna device has a length approximately half that of the antenna.

2. the second antenna has an end portion opposite to the tip short portion side of the first antenna, the end portion being disposed on a second slit side; 2. The antenna device according to claim 1, wherein the end of the first antenna opposite to the end short-circuiting portion of the first antenna is disposed on the third slit side.

3. The power supply of the first antenna is connected to the second frequency f ２ 2. The antenna device according to claim 1, further comprising a first filter that provides a low impedance in the first filter.

4. The power supply of the second antenna is connected to the first frequency f １ 2. The antenna device according to claim 1, further comprising a second filter that is a filter that provides high impedance in the first direction.

5. The second antenna is configured to receive the second frequency f ２ a third frequency f ３ It can operate with The power supply of the first antenna is connected to the third frequency f ３ 2. The antenna device according to claim 1, further comprising a third filter which is a filter that provides high impedance in the first and second directions.

6. A wireless communication device including an antenna device, The antenna device includes: First frequency f １ a first antenna that is a short-ended antenna operating at a second antenna disposed adjacent to the first antenna; The second antenna transmits the first frequency f １ a second frequency f that is lower than ２ Works with the second antenna has a feeding point on the side of the tip short-circuit portion of the first antenna, The second antenna has an open end on the opposite side to the tip short-circuit portion of the first antenna, The second antenna transmits the first frequency f １ Wavelength λ １ A wireless communication device having a length approximately half that of the conventional wireless communication device.

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