Antenna equipment

Abstract

According to the embodiment, an antenna device is provided that includes a substrate, a first antenna disposed on a first side surface of the substrate and radiating a signal in a first frequency band, a second antenna disposed on a second side surface adjacent to one side surface of the substrate and radiating a signal in a second frequency band that at least partially overlaps with the first frequency band, and a third antenna disposed between the first and second antennas and radiating a signal in a third frequency band lower than the first and second frequency bands, thereby preventing interference between the signals radiated by the first and second antennas.

Description

Technical Field

[0001] One embodiment of the present invention relates to an antenna device applicable to an electronic product having a communication function.

Background Art

[0002] An electronic product having a communication function includes an antenna device for transmitting and receiving electromagnetic waves. Such an antenna device operates in a specific resonance frequency band to transmit and receive electromagnetic waves.

[0003] The antenna device includes a conducting wire having an electrical length of λ / 2 with respect to a wavelength λ corresponding to the resonance frequency band. Such an antenna device transmits electromagnetic waves through the conducting wire, and as the electromagnetic waves form a standing wave on the conducting wire, resonance occurs in the antenna device.

[0004] In the case of recently developed electronic products, a number of antennas are arranged on a substrate to perform various functions. Each antenna can operate at a specific operating frequency to transmit and receive signals.

[0005] When such multiple antennas operate in different operating frequency bands, interference between signals does not occur. However, in some cases, the same communication method is used for some antennas. Or in some cases, the operating frequency bands are the same or some frequency bands may overlap.

[0006] When the operating frequency bands are the same or overlap in this way, there is a problem that interference between signals of the antennas occurs, degrading the communication quality. To prevent this, a solution of physically separating the antennas or arranging a separate isolation element to ensure the isolation performance is applied, but this has a problem of increasing the size of the substrate and the device.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The technical problem that this invention aims to solve is to provide an antenna device that can improve isolation performance and reduce the size of the substrate and electronic product. [Means for solving the problem]

[0008] According to the embodiment, an antenna device is provided that includes a substrate, a first antenna disposed on a first side surface of the substrate and radiating a signal in a first frequency band, a second antenna disposed on a second side surface adjacent to one side surface of the substrate and radiating a signal in a second frequency band that at least partially overlaps with the first frequency band, and a third antenna disposed between the first and second antennas and radiating a signal in a third frequency band lower than the first and second frequency bands, thereby preventing interference between the signals radiated by the first and second antennas.

[0009] The third antenna may be positioned, at least in part, in the region where the signal radiation area of ​​the first antenna and the signal radiation area of ​​the second antenna overlap.

[0010] The first and second frequency bands are 2400 to 2485 MHz, and the third frequency band may be 902 to 928 MHz.

[0011] The third antenna may include a first extension extending along the longitudinal direction of the first side surface of the substrate, a bridge portion formed by bending the first extension in the longitudinal direction of the second side surface, and a second extension extending from the bridge portion parallel to the first extension along the longitudinal direction of the first side surface of the substrate.

[0012] The first distance between the virtual extension line formed by extending the first extension along the longitudinal direction of the first side surface of the substrate and the end of the first antenna, and the second distance between the virtual extension line formed by extending the second extension along the longitudinal direction of the first side surface of the substrate and the end of the second antenna, can be the same within a predetermined error range.

[0013] The first distance and the second distance may be 5 mm.

[0014] The antenna device may further include a fourth antenna disposed on the second side surface of the substrate to radiate a signal in the second frequency band.

[0015] The end of the fourth antenna may be arranged to face a direction opposite to the end of the second antenna.

[0016] The ends of the first antenna and the second antenna may be arranged to face the same direction.

[0017] The end of the third antenna may be arranged such that its pointing direction is orthogonal to the end of the first antenna.

Advantages of the Invention

[0018] The antenna device according to the embodiment can improve the isolation performance.

[0019] Also, the communication performance can be improved.

[0020] Also, the sizes of the substrate and the electronic product can be reduced.

Brief Description of the Drawings

[0021] [Figure 1] It is a plan view showing an antenna device according to an embodiment of the present invention.

[0022] [Figure 2] It is a plan view showing an example of a first antenna according to an embodiment.

[0023] [Figure 3] It is a graph for explaining the operating performance of the first antenna in FIG. 2.

[0024] [Figure 4] It is an image showing the radiation pattern of the first antenna in FIG. 2.

[0025] [Figure 5] This is a drawing for explaining the detailed configuration of the antenna device according to the embodiment.

[0026] [Figure 6] This is a drawing for explaining the signal radiation regions of the respective antennas of the antenna device according to the embodiment.

[0027] [Figure 7] This is experimental data for explaining the isolation characteristics of the antenna device according to the embodiment.

[0028] [Figure 8a] This is experimental data for explaining the radiation efficiency of the antenna device according to the embodiment.

[0029] [Figure 8b] This is experimental data for explaining the radiation efficiency of the antenna device according to the embodiment.

[0030] [Figure 9a] This is experimental data for explaining the radiation efficiency of the antenna device according to the embodiment.

[0031] [Figure 9b] This is experimental data for explaining the radiation efficiency of the antenna device according to the embodiment.

Mode for Carrying Out the Invention

[0032] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0033] However, the technical idea of the present invention is not limited to some of the described embodiments and can be embodied in various different forms. Within the scope of the technical idea of the present invention, one or more of the components can be selectively combined and replaced between the embodiments for use.

[0034] Furthermore, unless explicitly defined, terms used in the embodiments of the present invention (including technical and scientific terms) may be interpreted in a way that is generally understood by a person skilled in the art to which the present invention pertains, and commonly used terms, such as those defined in dictionaries, may be interpreted considering their meaning in the context of the relevant art.

[0035] Furthermore, the terminology used in the embodiments of the present invention is for illustrative purposes only and is not intended to limit the present invention.

[0036] In this specification, singular types may also include plural types unless otherwise specified in the text, and when described as "A and / or at least one of B and C," it may include one or more of all possible combinations of A, B, and C.

[0037] Furthermore, when describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc., may be used.

[0038] Such terminology is merely used to distinguish one component from another, and is not limited by the nature, order, or sequence of the component in question.

[0039] Furthermore, when it is stated that one component is “connected,” “joined,” or “connected” to another component, this may include not only cases where the component is directly connected, joined, or connected to the other component, but also cases where it is “connected,” “joined,” or “connected” by yet another component between that component and the other component.

[0040] Furthermore, when described as being formed or positioned "above or below" each component, "above or below" includes not only cases where two components are in direct contact with each other, but also cases where one or more other components are formed or positioned between the two components. Also, when expressed as "above or below," it can include not only an upward direction but also a downward direction relative to one component.

[0041] The embodiments will be described in detail below with reference to the attached drawings. However, regardless of the reference numerals used in the drawings, identical or corresponding components will be assigned the same reference numerals, and redundant explanations will be omitted.

[0042] Figure 1 is a plan view illustrating an antenna device according to an embodiment of the present invention.

[0043] Referring to Figure 1, the antenna device 100 of this embodiment may include a substrate 110, a grounding element 120, first to fourth antennas 131 to 134, and an isolation element 140.

[0044] The substrate 110 may be provided in the antenna device 100 for power supply and support. The substrate 110 may have a flat plate structure. The substrate 110 may be a printed circuit board (PCB). Here, the substrate 110 may be embodied as a single substrate or as a plurality of substrates stacked together. Transmission lines (not shown) may be embedded in the substrate 110. Each transmission line may be connected to a control module (not shown) through one end. Each transmission line may also be exposed through the other end. That is, each transmission line can receive signals at the control module and transmit signals from one end to the other.

[0045] The substrate 110 may contain a dielectric material. The conductivity (σ) of the substrate 110 may be 0.02. The permittivity (ε) of the substrate 110 may be 4.4. Furthermore, the loss tangent of the substrate 110 may be 0.02. In this case, the transmission line may consist of a conductive material. Here, the transmission line may contain at least one of silver (Ag), palladium (Pd), platinum (Pt), copper (Gu), gold (Au), and nickel (Ni).

[0046] A grounding body 120 may be provided for grounding in the antenna device 100. Such a grounding body 120 may be formed on part or all of the substrate 110. In this case, the grounding body 120 may be positioned away from the transmission lines on the substrate 110. That is, the grounding body 120 may not be electrically connected to the transmission lines. Here, the grounding body 120 may be positioned on at least one of the bottom or top surfaces of the substrate 110. Or, if the substrate 110 consists of multiple substrates, the grounding body 120 may be positioned between the substrates. The grounding body 120 may be made of a metallic material. Here, the grounding body 120 may include at least one of silver (Ag), palladium (Pd), platinum (Pt), copper (Gu), gold (Au), and nickel (Ni).

[0047] Antenna 130 may be provided by antenna device 100 for signal transmission and reception. In this case, each antenna 130 can operate by being supplied with a signal by substrate 110. Each antenna 130 can operate in at least one predetermined resonant frequency band, which is called the operating frequency. Here, the operating frequencies of the antennas 130 may be the same or different. Also, each antenna 130 can resonate at a predetermined impedance.

[0048] The antenna 130 may be placed on the substrate 110. In this case, the antennas 130 may be placed spaced apart from each other. The antenna 130 may be placed on the upper surface of the substrate 110. The antenna 130 may be in contact with the transmission line. The antenna 130 may also be in contact with the grounding body 120. Furthermore, the antennas 130 may have the same shape or different shapes. The antenna 130 may be made of a conductive material. Here, the antenna 130 may include at least one of silver (Ag), palladium (Pd), platinum (Pt), copper (Gu), gold (Au), and nickel (Ni).

[0049] Antenna 130 may include antennas 131 to 134, from the first antenna to the fourth antenna.

[0050] Isolation element 140 may be provided in the antenna device 100 to prevent interference between the signals of the second antenna 132 and the fourth antenna 134. Isolation element 140 may be placed between the second antenna 132 and the fourth antenna 134. Isolation element 140 may be placed on the second side surface of the substrate.

[0051] Alternatively, if the substrate 110 consists of multiple substrates, the isolation element 140 may be placed between the substrates. The isolation element 140 can be in contact with the grounding body 120. The isolation element 140 may be made of a conductive material. For example, the isolation element 140 may include at least one of silver (Ag), palladium (Pd), platinum (Pt), copper (Gu), gold (Au), and nickel (Ni).

[0052] Figure 2 is a plan view illustrating an example of the first antenna according to the embodiment, and Figure 3 is a graph illustrating the operating performance of the first antenna in Figure 2. In this case, Figure 3 shows the change in the voltage standing wave ratio (VSWR) of the first antenna in the frequency domain. Figure 4 is an image illustrating the radiation pattern of the first antenna in Figure 2.

[0053] Referring to Figure 2, each of the first antennas 131 in the embodiment may include a feed section 1311, a ground section 1313, and a radiator 1315.

[0054] The power supply unit 1311 can supply signals via the first antenna 131. The power supply unit 1311 can be connected to a transmission line through one end. In this case, the power supply unit 1311 may not be in contact with the grounding body 120. One end of the power supply unit 1311 can be defined as the feeding point (FP). The feeding point is located close to the grounding body 120 and can be in contact with the transmission line. Through this, a signal can be supplied from the control module to the power supply unit 1311. The power supply unit 1311 can also be extended from the feeding point through the other end. Through this, the power supply unit 1311 can supply a signal from one end to the other.

[0055] The grounding section 1313 can ground the first antenna 130. Such a grounding section 1313 can be connected to a grounding body 120 through one end. Here, one end of the grounding section 1313 can be defined as a grounding point, and this grounding point can be in contact with the grounding body 120. The grounding section 1313 can also be extended from the grounding point through the other end. Furthermore, the grounding section 1313 can be connected to a feed point 1311. Through this, the grounding section 1313 can be grounded to the grounding body 120. In addition, signals can be transmitted from the feed point 1311 to the grounding body 120 via the grounding section 1313.

[0056] A radiator 1315 may be provided for the substantial operation of the first antenna 130. The radiator 1315 can radiate a signal in the resonant frequency band. Such a radiator 1315 may be connected to the feed point 1311 and the ground point 1313 through one end. The radiator 1315 may then extend from the feed point 1311 and the ground point 1313 through the other end. The other end of the radiator 1315 may be open. The radiator 1315 may also be formed in a bar type. Through this, a signal can be supplied from the feed point 1311 to the radiator 1315, and the radiator 1315 can radiate a signal. In this case, the size of the radiator 1315 may be determined according to the resonant frequency band. The electrical length of the radiator 1315 may be determined to be λ / 8 with respect to the wavelength λ corresponding to the resonant frequency band.

[0057] According to the embodiment, the first antenna 131 can operate in a single resonant frequency band, as shown in Figure 3. The operating frequency band of the first antenna may be approximately 2.4 GHz. In the resonant frequency band, the radiation pattern of the antenna 130 may be as shown in Figure 4.

[0058] In this embodiment, the second to fourth antennas may be configured to include the same feed point, grounding point, radiator, etc., as the first antenna described above. However, in the case of the third antenna, its shape and operating frequency band may differ from the other antennas. A detailed explanation related to this will be given in Figure 5 below.

[0059] Figure 5 is a diagram illustrating the detailed configuration of the antenna device according to the embodiment, and Figure 6 is a diagram illustrating the signal radiation area of ​​each antenna of the antenna device according to the embodiment.

[0060] Referring to Figure 5, the antenna device according to the embodiment may include a substrate and the first to fourth antennas.

[0061] The substrate 110 can have a flat plate structure. The substrate 110 is a printed circuit board and can have a flat plate structure. Transmission lines are embedded in the substrate 110, and each transmission line can be connected to a control module through one end. Each transmission line can receive a signal at the control module and transmit the signal to each of the connected antennas. In this embodiment, the substrate may be formed with an X-axis length of 80 mm and a Y-axis length of 67.5 mm, but substrates of various sizes can be used depending on the application, size, and number of antennas and elements to be placed in the electronic product to which it is applied.

[0062] The first antenna 131 is positioned on the first side surface of the substrate 110 and can radiate signals in a first frequency band. The first antenna 131 may include a feed point 1311 extending from one end and a radiator 1313 that bends and extends from the feed point 1311 to the other end. A bend 1314 may be formed between the feed point 1311 and the radiator 1313 of the first antenna 1311 so that their directions of pointing to each other are perpendicular. The feed point 1311 of the first antenna may be connected to a transmission line on the substrate 110, and the radiator 1315 may be positioned facing the opposite direction from where the second antenna 132 is located. In this embodiment, the first antenna 131 is an antenna element that performs Zigbee communication and may have an operating frequency band of 2400 to 2485 MHz.

[0063] The second antenna 132 is positioned on a second side of the substrate 110 adjacent to the first side, and can radiate signals in a second frequency band that overlaps with at least a portion of the first frequency band. The second antenna 132 may include a feed point 1321 extending from a feed point at one end, and a radiator 1325 that bends and extends from the feed point 1321 to the other end. A bend 1324 may be formed between the feed point 1321 and the radiator 1325 of the second antenna 1322 so that their directions of directional orientation are perpendicular to each other. The feed point 1321 of the second antenna 132 may be connected to a transmission line of the substrate 110, and the radiator 1325 may be positioned to face the opposite direction from where the fourth antenna 134 is located. That is, the end of the second antenna 132 may be positioned so that its direction of directional orientation is perpendicular to that of the end of the first antenna 131. In this embodiment, the second antenna 132 is an antenna element that performs Wi-Fi communication and can have an operating frequency band of 2400 to 2485 MHz.

[0064] The third antenna 133 is positioned between the first antenna 131 and the second antenna 132 and radiates signals in a third frequency band lower than the first and second frequency bands, thereby preventing interference between the signals radiated by the first antenna 131 and the second antenna 132. The third antenna 133 may include a first extension 1332 extending along the longitudinal direction of the first side surface of the substrate 100, a bridge portion 1334 formed by bending from the first extension 1332 along the longitudinal direction of the second side surface, and a second extension 1336 extending from the bridge portion 1334 along the longitudinal direction of the first side surface of the substrate 100 parallel to the first extension 1332. One end of the first extension 1332 may be connected to a feed point 1331, and the other end may extend along the longitudinal direction of the first side surface of the substrate 100 and be connected to the bridge portion 1334. The bridge section 1334 extends in a direction perpendicular to the first extension section 1332, with one end connected to the first extension section 1332 and the other end connected to the second extension section 1336. The second extension section 1336 is formed along the longitudinal direction of the first side surface of the substrate 100, with one end connected to the bridge section 1334 and the other end provided with a radiator 1335. The radiator 1335 of the third antenna 133 can face the same direction as the radiator 1313 of the first antenna 131. That is, the ends of the first antenna 131 and the ends of the third antenna 133 can be positioned to face the same direction.

[0065] Unlike the embodiment, the ends of the first antenna 131 and the third antenna 133 may be positioned so that they face in opposite directions. That is, the third antenna 133 can perform its function as an isolation element by being designed to be long enough to have an operating frequency that prevents signal interference between the first antenna 131 and the second antenna 132, and the directional direction of the radiator may be changed depending on the design environment.

[0066] The third antenna 133 can radiate signals in an operating frequency band lower than the first and second frequency bands. The length of the antenna can be determined according to the radio frequency used. The length of the antenna can be determined by the wavelength (λ) of the radio wave, and the wavelength of the radio wave is inversely proportional to the frequency used. Therefore, the length of the antenna can be determined by the frequency used. That is, the length of the antenna is determined by the radio frequency used, and the higher the radio frequency, the shorter the antenna length, and the lower the frequency, the longer the antenna length. Therefore, in this embodiment, the lower the operating frequency of each antenna, the longer the wavelength, and thus the longer the antenna length must also be.

[0067] Antenna length can be designed to optimize antenna efficiency and impedance matching. The minimum antenna length required for signal transmission and reception is λ / 4, and the optimal antenna length for signal transmission and reception can be determined to be λ / 2.

[0068] Therefore, the optimal antenna length for signal transmission and reception can be determined by the following mathematical formula 1.

[0069]

number

[0070] In equation 1, L is the antenna length for optimal signal transmission and reception, c is the speed of light, and f is the antenna's operating frequency. Therefore, the length of the third antenna can be designed and positioned to be approximately 2.6 times longer than the lengths of the first and second antennas, depending on the operating frequency.

[0071] By designing and positioning the third antenna 133 to be longer than the first antenna 131 and the second antenna 132, it can effectively perform the role of an isolator, preventing signal interference between the first antenna 131 and the second antenna 132. In other words, by designing the operating frequency of the third antenna 133 to be sufficiently lower than the operating frequencies of the first antenna 131 and the second antenna 132, the third antenna 133 can be designed to be longer and positioned between the first antenna 131 and the second antenna 132, thereby efficiently preventing signal interference between the first antenna 131 and the second antenna 132. For this purpose, in the embodiment, the operating frequencies of the first antenna 131 and the second antenna 132 may be set to be more than twice as high as the operating frequency of the third antenna 133.

[0072] The operating frequency characteristics of the first antenna 131 to the fourth antenna 134 in this embodiment can be summarized as shown in Table 1 below.

[0073] [Table 1]

[0074] The first distance L1 between the end of the first antenna 131 and a virtual extension line VL1 formed by extending the first extension portion 1332 of the third antenna 133 along the longitudinal direction of the first side surface of the substrate 100 may be the same as the second distance L2 between the end of the second antenna 132 and a virtual extension line VL2 formed by extending the second extension portion 1336 along the longitudinal direction of the first side surface of the substrate 100 and a virtual extension line VL2 formed by extending the second extension portion 1336 along the longitudinal direction of the first side surface of the substrate 100. The first distance L1 may represent the minimum straight-line distance between the virtual extension line VL1 formed by the radiator 1335 of the third antenna 133 extending along the longitudinal direction of the first side surface and along the X-axis direction in which the first antenna 131 is located, and the radiator 1315 of the first antenna 131.

[0075] Furthermore, the second distance L2 may represent the minimum straight-line distance between the virtual extension line VL2, which is formed by the second extension 1336 of the third antenna 133 extending along the longitudinal direction of the first side surface and along the X-axis direction in which the second antenna 132 is located, and the radiator 1325 of the second antenna 132.

[0076] The first distance L1 and the second distance L2 can be the same within a predetermined error range; for example, the first distance L1 and the second distance L2 can be 5 mm. Through such an arrangement, interference between signals between the first antenna 131 and the second antenna 132 can be minimized, taking into account the operating frequencies of the first antenna 131 to the third antenna 133, the antenna lengths, and the size of the substrate.

[0077] Figure 6 is a diagram illustrating the signal radiation regions of the first antenna and the second antenna to explain the isolation performance of the third antenna.

[0078] Referring to Figure 6(a), it can be seen that if the third antenna is not positioned, signal interference will occur because a considerable portion of the signal radiation region A1 of the first antenna and the signal radiation region A2 of the second antenna overlap. Referring to Figure 6(b), it can be seen that if the third antenna is positioned in a "straight" shape, signal interference will occur because a portion of the signal radiation region A1 of the first antenna and the signal radiation region A2 of the second antenna overlap. Referring to Figure 6(c), it can be seen that if the third antenna is positioned in the form according to the embodiment, it can be seen that the signal radiation region A1 of the first antenna and the signal radiation region A2 of the second antenna do not overlap, and no signal interference will occur. In other words, by designing the operating frequencies of the first and second antennas to be at least twice as high as the operating frequency of the third antenna, and positioning the third antenna for a sufficiently long distance between the first and second antennas, signal interference between the first and second antennas can be effectively prevented.

[0079] If they are not positioned correctly, it can be confirmed that signal interference will occur because the signal radiation regions of the first antenna and the second antenna overlap to a considerable extent.

[0080] Figure 7 shows experimental data to illustrate the isolation characteristics of the antenna device according to the embodiment.

[0081] Figure 7(b) shows that, compared to the case where the third antenna is arranged in a "straight" shape as shown in Figure 7(a), the isolation performance improved by approximately 10 dB or more, from -10 dB to -20 dB, when the third antenna is arranged according to the embodiment.

[0082] Figures 8 and 9 show experimental data illustrating the radiation efficiency of the antenna device according to the embodiment.

[0083] Referring to Figures 8(a) and 8(b), it can be confirmed that the radiation efficiency of the first antenna, the Zigby antenna, improved by at least approximately 8% and in many cases by more than approximately 25% in the operating frequency band.

[0084] Referring to Figures 9(a) and 9(b), it can be confirmed that the radiation efficiency of the third antenna, the Wi-Fi antenna, improved by at least approximately 9% and in many cases by more than 18% in the operating frequency band.

[0085] This improvement in isolation performance and radiation efficiency is due to the third antenna reflecting electromagnetic signals radiated from the first and second antennas, forming maximum directivity in the opposite direction, and canceling out interference phenomena between the antennas.

[0086] Referring again to Figure 5, the fourth antenna 134 is positioned on the second side surface of the substrate 110 and can radiate signals in the second frequency band. The fourth antenna 134 may include a feed point 1341 extending from one end and a radiator 1345 that bends and extends from the feed point 1341 to its end. The feed point 1341 and the radiator 1345 of the fourth antenna 134 may have a bend 1344 formed between them so that their directions of pointing to each other are perpendicular. The feed point 1341 of the fourth antenna 134 may be connected to a transmission line on the substrate 100, and the radiator 1345 may be positioned facing the opposite direction from where the second antenna 132 is located. That is, the end of the fourth antenna 134 may be positioned facing the opposite direction from the end of the second antenna 132. In this embodiment, the fourth antenna 134 is an antenna element that performs Zigbee communication and may have an operating frequency band of 2400 to 2485 MHz.

[0087] An isolation element 140 may be placed between the second antenna 132 and the fourth antenna 134. The isolation element may be provided to prevent interference between the signals of the second antenna 132 and the fourth antenna 134. The isolation element 140 may be placed on the second side surface of the substrate 100 and may be placed between the feed point 1321 and bend 1324 of the second antenna 132 and the feed point 1341 and bend 1344 of the fourth antenna 134.

[0088] In this embodiment, the term "~part" refers to software or hardware components such as FPGAs (field-programmable gate arrays) or ASICs, and the "~part" performs some role. However, the meaning of "~part" is not limited to software or hardware. The "~part" may be configured to reside on an addressable storage medium, or it may be configured to regenerate one or more processors. Thus, as an example, the "~part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, processors, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. Components and the functions provided within the "~part" may be combined with a smaller number of components and "~parts," or further separated into additional components and "~parts." Moreover, components and "~parts" may be embodied to regenerate one or more CPUs within a device or security multimedia card.

[0089] While preferred embodiments of the present invention have been described above with reference to the present invention, those skilled in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and scope of the invention as set forth in the following claims. [Explanation of symbols]

[0090] 100: Antenna device 110: Circuit board 120: Ground body 130: Antenna 131: First Antenna 132: Second Antenna 133: Third Antenna 134: Fourth Antenna 140: Isolation element

Claims

1. circuit board and A first antenna is positioned on the first side surface of the substrate and radiates a signal in the first frequency band, A second antenna is positioned on a second side adjacent to one side of the substrate and radiates a signal in a second frequency band that overlaps with the first frequency band in at least a portion thereof. An antenna device comprising: a third antenna positioned between the first antenna and the second antenna, which radiates signals in a third frequency band lower than the first and second frequency bands, and which prevents interference between the signals radiated by the first and second antennas.

2. The antenna device according to claim 1, wherein at least a portion of the third antenna is arranged in the region where the signal radiation region of the first antenna and the signal radiation region of the second antenna overlap.

3. The antenna device according to claim 1, wherein the first frequency band and the second frequency band are 2400 to 2485 MHz, and the third frequency band is 902 to 928 MHz.

4. The third antenna has a first extension portion that extends along the longitudinal direction of the first side surface of the substrate, A bridge portion formed by bending the first extension portion in the longitudinal direction of the second side surface, The antenna device according to claim 1, further comprising: a second extension extending from the bridge portion parallel to the first extension along the longitudinal direction of the first side surface of the substrate.

5. The antenna device according to claim 4, wherein the first distance between a virtual extension line formed by extending the first extension along the longitudinal direction of the first side surface of the substrate and the end of the first antenna is the same as the second distance between a virtual extension line formed by extending the second extension along the longitudinal direction of the first side surface of the substrate and the end of the second antenna, within a predetermined error range.

6. The antenna device according to claim 5, wherein the first distance and the second distance are 5 mm.

7. The antenna device according to claim 1, further comprising a fourth antenna disposed on the second side surface of the substrate and radiating a signal in the second frequency band.

8. The antenna device according to claim 7, wherein the end of the fourth antenna is positioned to face in the opposite direction to the end of the second antenna.

9. The antenna device according to claim 1, wherein the end of the first antenna and the end of the third antenna are arranged to face the same direction.

10. The antenna device according to claim 9, wherein the end of the second antenna is arranged so as to be perpendicular to the direction of directional alignment with the end of the first antenna.

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