Radiating fan antenna

Abstract

The invention discloses a cooling fan antenna, which is arranged on a mainboard or a ground plane in a notebook computer, and comprises an airflow guide structure, a fan and a coaxial feeder line, the airflow guide structure comprises an upper metal sheet and a lower metal sheet which are parallel to each other and at least one metal connecting piece connected between the upper metal sheet and the lower metal sheet, the upper metal sheet and the lower metal sheet are parallel to each other, the upper metal sheet is provided with a first opening part, the lower metal sheet is attached to the ground plane of the mainboard, and the upper metal sheet and the lower metal sheet are used for forming a second opening part. The fan is arranged in the airflow guiding structure and corresponds to the first opening part. The coaxial feed line is connected with the feed-in point of the upper metal sheet from the outside of the airflow guide structure, and is used for exciting a basic resonance mode with the frequency range of 2.4 GHz and exciting at least one high-order resonance mode with the frequency range of 5 GHz and 6 GHz. Moreover, the feed-in point is located between the first opening part and the second opening part. According to the invention, the requirement of multiband use can be met.

Description

Technical Field

[0001] This invention relates to an antenna, and more particularly to a cooling fan antenna. Background Technology

[0002] Terminal devices, such as laptops or all-in-one computers, have limited size. While performance can be improved, the size cannot be increased accordingly. The size of terminal devices is designed according to user needs and cannot be increased indefinitely. Generally speaking, the antennas of terminal devices are mainly designed to be hidden or concealed, and are not exposed outside the casing. In this way, the antenna components compete with all other components for limited internal space inside the device.

[0003] However, limited space increases the difficulty of antenna design. While larger available space allows for potentially better antenna performance, built-in antennas are typically constrained by increasingly smaller available spaces. This means that, in reality, the need for improved antenna performance is often at odds with the availability of sufficient space. The challenges in designing built-in antennas for terminal devices are becoming increasingly difficult. For example, with the adoption of WiFi 6E in terminal devices, wireless LANs are further utilizing the 6GHz band, significantly expanding the operating frequency range of built-in antennas. Summary of the Invention

[0004] In view of the above-mentioned defects in the prior art, the present invention aims to provide a cooling fan antenna that integrates the antenna with the cooling fan, thereby solving the problem of antenna space occupation.

[0005] The technical solution of this invention is as follows: a cooling fan antenna, disposed on the motherboard inside a laptop computer or disposed on a ground plane, the cooling fan antenna comprising: An airflow guiding structure includes an upper metal plate, a lower metal plate, and at least one metal connector. The upper metal plate and the lower metal plate are parallel to each other. The upper metal plate has a first opening. The lower metal plate is attached to the ground plane of the main board. The metal connector is connected between the upper metal plate and the lower metal plate. The upper metal plate and the lower metal plate are used to form a second opening. A fan is disposed within the airflow guiding structure and corresponds to the first opening; and A coaxial feed line is connected from the outside of the airflow guiding structure to the feed point of the upper metal sheet, for exciting a fundamental resonant mode with a frequency range of 2.4 GHz, and for exciting at least one higher-order resonant mode with a frequency range of 5 GHz and 6 GHz. The feed point is located between the first opening and the second opening.

[0006] Furthermore, the upper metal sheet is composed of a semi-circular disk and a rectangle, with one long side of the rectangle completely overlapping the diameter side of the semi-circular disk. The length of the long side of the rectangle is the same as the length of the diameter side of the semi-circular disk, and the ratio of the long side to the short side of the rectangle is 2:1. The outer contour of the lower metal sheet is the same as the outer contour of the upper metal sheet.

[0007] Furthermore, the radius of the semi-circular disk is 40 mm, the first opening is a circular opening with a radius of 26 mm, and the distance between the upper metal plate and the lower metal plate is 6 mm.

[0008] Furthermore, the distance between the feed point and the center of the semi-disc is 40 mm, and the distance between the feed point and the short side of the rectangle is 10 mm.

[0009] Furthermore, the cooling fan antenna includes at least one metal locking fastener connected between the upper metal plate and the lower metal plate for adjusting impedance matching.

[0010] Furthermore, the cooling fan antenna is a planar inverted F-shaped antenna or a short-circuited monopole antenna.

[0011] Furthermore, the cooling fan antenna is a wireless local area network antenna operating at 2.4GHz, 5GHz, and 6GHz.

[0012] Furthermore, the scattering parameter S11 of the cooling fan antenna in the operating frequency ranges of 2.4GHz, 5GHz and 6GHz meets the specification of -3dB.

[0013] Furthermore, the first opening is an air inlet, and the second opening is an air outlet.

[0014] Compared with the prior art, the advantages of the technical solution of the present invention are as follows: This invention achieves complete integration of the antenna and the airflow guidance structure of the cooling fan, thus eliminating the need for a separate antenna space (such as an antenna window or empty area) for the antenna itself. It can be applied to wireless local area networks including at least the 2.4GHz and 5GHz frequency bands. The antenna can selectively and maximize the use of the large space around the cooling fan, enhancing the antenna's design flexibility and possessing high industrial application value. Attached Figure Description

[0015] Figure 1 This is a three-dimensional schematic diagram of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention.

[0016] Figure 2 This is an exploded view of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention from a top view.

[0018] Figure 4 This is a schematic diagram of multiple metal connectors for a laptop cooling fan antenna provided in another embodiment of the present invention.

[0019] Figure 5 This is a graph showing the scattering parameter S11 of the cooling fan antenna of a laptop computer as a function of frequency, according to an embodiment of the present invention.

[0020] Figure 6 This is a radiation field pattern diagram of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention in the YZ plane at a frequency of 2.4 GHz.

[0021] Figure 7 This is a radiation field pattern diagram of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention in the XZ plane at a frequency of 2.4 GHz.

[0022] Figure 8 This is a graph showing the antenna efficiency of the laptop cooling fan antenna in free space as a function of frequency, according to an embodiment of the present invention.

[0023] Figure 9 This is a graph showing the peak gain of the laptop cooling fan antenna in free space as a function of frequency, according to an embodiment of the present invention. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments, but these are not intended to limit the scope of the invention.

[0025] Please refer to Figures 1 to 3 , Figure 1 This is a three-dimensional schematic diagram of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention. Figure 2 This is an exploded view of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention. Figure 3 This is a top-view schematic diagram of a laptop cooling fan antenna provided in an embodiment of the present invention. This embodiment provides a laptop cooling fan antenna, disposed within the motherboard of the laptop, the motherboard including radio frequency circuitry. The cooling fan antenna includes an airflow guiding structure 1, a fan 2, and a coaxial feed line 3. The airflow guiding structure 1 includes an upper metal plate 11, a lower metal plate 12, and at least one metal connector 13. The airflow guiding structure 1 itself has two openings, a first opening 101 and a second opening 102. For example, the first opening 101 is an air inlet, and the second opening 102 is an air outlet. The airflow direction is determined by the airflow generated by the operation of the fan 2. Figure 1 Fan 2 is not shown in the drawing; it is enclosed by airflow guiding structure 1. Figure 2 The diagram illustrates the relative positions of the assembled fan 2. The upper metal plate 11 and the lower metal plate 12 are parallel to each other. The upper metal plate 11 has a first opening 101, and the lower metal plate 12 is attached to the ground plane 4 of the motherboard. The ground plane 4 and the RF circuit of the motherboard share a common ground.

[0026] Continue to refer to Figure 1 and Figure 2 A metal connector 13 connects the upper metal sheet 11 and the lower metal sheet 12. The metal connector 13 is used to short-circuit the upper metal sheet 11 to the lower metal sheet 12. The metal connector 13 can be a thin strip or a complete sheet for side coverage; it is not limited. In other words, the upper metal sheet 11 must have a short-circuit point, which is the connection point of the metal connector 13. The metal connector 13... Figure 1 The middle section is perpendicular to the upper metal sheet 11 and the lower metal sheet 12, used to connect the upper metal sheet 11 and the lower metal sheet 12, but its shape is not limited. Figure 2 The metal connector 13 is not shown in the figure because the position of the metal connector 13 can be anywhere between the upper metal plate 11 and the lower metal plate 12.

[0027] The upper metal sheet 11 and the lower metal sheet 12 form the second opening 102. Structurally, this second opening 102 is perpendicular to the upper metal sheet 11 and the lower metal sheet 12. To achieve a complete opening structure, for example in... Figure 1 The middle part is a rectangular opening, and a side structure is also required. The side structure can be made of metal parts or non-metal parts (such as insulating parts), as long as gas can flow through the second opening 102.

[0028] This integrated fan and antenna cooling fan antenna is applicable in three scenarios. The first is for laptops with non-metallic casings. The second scenario applies when the laptop casing is mostly metal; the casing around the cooling fan is made non-metallic or non-conductive, making it easier for the cooling fan antenna to propagate electromagnetic energy outside the casing. The third scenario involves laptops with entirely metal casings. In this case, the second opening 102 serves as the entry and exit point for electromagnetic energy propagation. The airflow guiding structure 1 is designed to be mostly (or entirely) metal, creating a resonant cavity within it. This allows electromagnetic energy to leak through the second opening 102. In this third scenario, the all-metal casing of the laptop does not cause irreparable negative impacts on antenna performance. The choice between these three scenarios depends on the application product; the optimal design is selected without limitation.

[0029] The fan 2 is disposed within the airflow guiding structure 1 and corresponds to the first opening 101, as can be seen from... Figure 2 The corresponding position. The locking method for fan 2 is not limited. Figure 2 This is merely an example. The first opening 101 is typically a circular opening, such as a collection of multiple smaller openings or a mesh-like opening, but is not limited thereto. The fan diameter of the fan 2 is approximately similar to the radius of the first opening 101. The fan diameter of the fan 2 may be slightly larger or smaller than the radius of the first opening 101, for example, to design for more stable airflow or greater flow rate, but the invention is not limited thereto.

[0030] The coaxial feed line 3 is externally connected to the feed point FP of the metal plate 11 via the airflow guiding structure 1. It is used to excite a fundamental resonant mode in the frequency range of 2.4 GHz, and to excite at least one higher-order resonant mode in the frequency range of 5 GHz and 6 GHz. For example, there may be two or more higher-order resonant modes in the 5 GHz and 6 GHz range to cover a wider frequency application range. Preferably, the feed point FP is located between the first opening 101 and the second opening 102. Specifically, the opposite ends of the coaxial feed line 3 are connected to the radio frequency circuit (not shown) and the feed point FP, respectively. At the radio frequency circuit end, the center conductor of the coaxial feed line 3 is connected to the signal terminal of the radio frequency circuit, and the outer conductor of the coaxial feed line 3 is connected to the ground terminal of the radio frequency circuit. At the feed point FP end, the center conductor of the coaxial feed line 3 is connected to the feed point FP, while the outer conductor is floating. Therefore, the coaxial feed line 3 is only used to introduce the excitation signal, and the antenna grounding mechanism is determined by the grounding type of the metal connector 13.

[0031] Reference Figure 3 Preferably, the upper metal sheet 11 consists of a semi-circular disk 111 and a rectangle 112, wherein one long side 112a of the rectangle 112 completely overlaps with one diameter side of the semi-circular disk, and this completely overlapping long side 112a... Figure 3 The rectangle 112 is represented by a dashed line. The length of the long side 112a of the rectangle 112 is the same as the length of the diameter side of the semicircular disk 111. Furthermore, the ratio of the long side 112a to the short side 112b (or short side 112d) of the rectangle 112 is two to one. Alternatively, the outer contour of the upper metal sheet 11 can also be considered as a complete disk 113 superimposed on the rectangle 112. Figure 3In the diagram, a portion of the circumference of the complete disk 113 is represented by a dashed line. The complete disk 113 and the semi-disk 111 have the same center and the same radius. Furthermore, the long side 112a of the rectangle 112 is the diameter of the complete disk 113 (completely overlapping), and the length of the short side 112b (or short side 112d) of the rectangle 112 is the radius of the complete disk 113, such that the other long side 112c of the rectangle 112 is tangent to the circumference of the complete disk 113. When the rectangle 112 overlaps with the diameter of the complete disk 113 using one of its long sides 112a, the resulting overlapping area constitutes the upper metal sheet 11. Preferably, the outer contour of the lower metal sheet 12 is the same as the outer contour of the upper metal sheet 11. Next, since the size of the antenna affects the excitation mode frequency, a preferred size example is: the radius of the semicircular disk 111 is 40 mm, the first opening 101 is a circular opening with a radius of 26 mm, and the distance between the upper metal plate 11 and the lower metal plate 12 is 6 mm. The distance between the feed point FP and the center of the semicircular disk 111 is 40 mm, and the distance between the feed point FP and the short side 112b of the rectangle 112 is 10 mm.

[0032] refer to Figure 4 Furthermore, the cooling fan antenna further includes at least one metal locking fastener 14 connected between the upper metal plate 11 and the lower metal plate 12 for adjusting impedance matching. Alternatively, the cooling fan antenna further includes multiple metal locking fasteners 14 connected between the upper metal plate 11 and the lower metal plate 12 for adjusting impedance matching. Figure 4 In the middle, the airflow guiding structure 1 has two metal fasteners 14 on its side, and Figure 4 Other locations on the sides shown are covered by insulating structures, such as insulating structures 15a, 15b, 15c, 15d, and 15e. The location of the metal fastener 14, whether one or more, can be selected as needed and is not limited. The metal fastener 14 can work in conjunction with the metal connector 13 to adjust the imaginary impedance of the antenna. Alternatively, the metal fastener 14 can be a plate covering the entire side, so that the airflow guiding structure 1, except for the second opening 102, is completely covered by a metal structure, or only partially covered by metal. The degree of metal coverage on the sides can also be used to partially improve antenna efficiency.

[0033] In terms of the excitation mode, the cooling fan antenna can be considered, for example, as a planar inverted F-shaped antenna or a short-circuited monopole antenna. The cooling fan antenna is a wireless LAN antenna operating at 2.4 GHz, 5 GHz, and 6 GHz, and is also suitable for the newer frequency bands (5925 MHz to 7125 MHz) used in the currently widely adopted WiFi 6E standard. The scattering parameter S11 of the cooling fan antenna in the 2.4 GHz, 5 GHz, and 6 GHz operating frequency range meets the specification of at least -3 dB or better. (Reference) Figure 5 Although the center frequency of the fundamental mode does not precisely correspond to 2.4 GHz due to the size of the airflow guiding structure 1, a slight adjustment to the size of the airflow guiding structure 1 can slightly increase the center frequency, allowing the scattering parameter S11 at 2.4 GHz to meet the -6 dB requirement, without significantly affecting the impedance matching of modes operating above 5 GHz. In any case, as will be explained later, in terms of mass production specifications, the antenna efficiency and peak gain in the 5 GHz and 6 GHz operating bands meet the usage requirements.

[0034] Reference Figure 6 and Figure 7 , Figure 6 This is a radiation field pattern diagram of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention in the YZ plane at a frequency of 2.4 GHz. Figure 7 This is a radiation pattern diagram of the cooling fan antenna of a laptop computer provided in an embodiment of the present invention in the XZ plane at a frequency of 2.4 GHz. Figure 6 and Figure 7 The radiation pattern refers to the case where the casing surrounding the cooling fan is non-metallic or non-conductive. This relates to the three application scenarios described above, depending on the laptop casing, specifically the first and second scenarios. Around 2.4GHz, the radiation pattern of two mutually orthogonal vertical sections relative to ground plane 2 partially approximates a planar inverted F-shaped antenna or a monopole antenna. That is, it slightly approximates the radiation pattern of a monopole antenna on a large ground plane. Depending on the location of the metal connector, the antenna of this invention can be considered a planar inverted F-shaped antenna or a short-circuited monopole antenna in the 2.4GHz band. Furthermore, the radiation pattern is more complex in the 5GHz and 6GHz ranges and will not be discussed here. It should be noted that the cooling fan antenna can be designed, for example, at the bottom of the laptop casing. Whether the +Z direction of the radiation pattern points upwards or downwards depends on the fan's configuration on the motherboard; both are possible and therefore not limited.

[0035] in accordance with Figure 6 and Figure 7 Regarding the radiation pattern and antenna efficiency... Figure 8 This is a graph showing the antenna efficiency of the laptop cooling fan antenna in free space as a function of frequency, according to an embodiment of the present invention. The antenna efficiency at 2.4 GHz is better than -6 dB. The reason why the optimal antenna efficiency near 2.4 GHz was not designed to be between 2400 MHz and 2500 MHz is that the size of the airflow guiding structure of the cooling fan is often limited by the cooling requirements of the machine model and cannot be significantly adjusted. Figure 8 In terms of examples, no optimization has been achieved; as long as the specifications are met, it's sufficient. Antenna efficiency is better than -7.5dB or better at 5GHz, -7.5dB around 5150MHz, and better than -6dB at most higher frequencies. Regarding peak gain... Figure 9 This is a graph showing the peak gain of the laptop cooling fan antenna in free space as a function of frequency, according to an embodiment of the present invention. In a common mass-production specification for laptops, a lower limit and an upper limit for the peak gain are defined. Figure 9 In the diagram, the solid line with vertically intersecting short lines represents the lower limit of the specification, while the thick solid line represents the upper limit of the specification. The actual peak gain curve of the antenna is represented by a solid line marked with a hollow circle. Figure 9 This shows that the antenna's peak gain is within the range defined by the upper and lower limits of the specification, thus meeting the specifications for mass production.

[0036] In summary, the laptop cooling fan antenna provided in this embodiment of the invention can be applied to wireless local area networks including the 2.4GHz and 5GHz frequency bands, and even to the 6GHz frequency band (ranging from 5925MHz to 7125MHz) of the WiFi 6E standard. Furthermore, this invention achieves integration of the antenna and the cooling fan. Because the airflow guidance structure of the antenna and the cooling fan is completely integrated, the antenna body does not need to occupy separate antenna space (such as an antenna window or empty area). The antenna can selectively and maximize the use of the large space around the cooling fan, thus improving the antenna design flexibility and possessing high industrial application value.

Claims

1. A cooling fan antenna, characterized in that, The motherboard located inside a laptop computer includes a cooling fan antenna comprising: An airflow guiding structure includes an upper metal plate, a lower metal plate, and at least one metal connector. The upper metal plate and the lower metal plate are parallel to each other. The upper metal plate has a first opening. The lower metal plate is attached to the ground plane of the main board. The metal connector is connected between the upper metal plate and the lower metal plate. The upper metal plate and the lower metal plate are used to form a second opening. A fan is disposed within the airflow guiding structure and corresponds to the first opening; and A coaxial feed line is connected from the outside of the airflow guiding structure to the feed point of the upper metal sheet, for exciting a fundamental resonant mode with a frequency range of 2.4 GHz, and for exciting at least one higher-order resonant mode with a frequency range of 5 GHz and 6 GHz. The feed point is located between the first opening and the second opening.

2. A cooling fan antenna, characterized in that, The cooling fan antenna, positioned at ground level, includes: An airflow guiding structure includes an upper metal plate, a lower metal plate, and at least one metal connector. The upper metal plate and the lower metal plate are parallel to each other. The upper metal plate has a first opening. The lower metal plate is attached to the ground plane of the main board. The metal connector is connected between the upper metal plate and the lower metal plate. The upper metal plate and the lower metal plate are used to form a second opening. A fan is disposed within the airflow guiding structure and corresponds to the first opening; and A coaxial feed line is connected from the outside of the airflow guiding structure to the feed point of the upper metal sheet, for exciting a fundamental resonant mode with a frequency range of 2.4 GHz, and for exciting at least one higher-order resonant mode with a frequency range of 5 GHz and 6 GHz. The feed point is located between the first opening and the second opening.

3. The cooling fan antenna according to claim 1 or 2, characterized in that, The upper metal sheet is composed of a semi-circular disk and a rectangle, with one long side of the rectangle completely overlapping the diameter side of the semi-circular disk. The length of the long side of the rectangle is the same as the length of the diameter side of the semi-circular disk, and the ratio of the long side to the short side of the rectangle is 2:

1. The outer contour of the lower metal sheet is the same as the outer contour of the upper metal sheet.

4. The cooling fan antenna according to claim 3, characterized in that, The radius of the semi-circular disk is 40 mm, the first opening is a circular opening with a radius of 26 mm, the distance between the upper metal plate and the lower metal plate is 6 mm, the distance between the feed point and the center of the semi-circular disk is 40 mm, and the distance between the feed point and the short side of the rectangle is 10 mm.

5. The cooling fan antenna according to claim 1 or 2, characterized in that, The cooling fan antenna includes at least one metal locking element connected between the upper metal plate and the lower metal plate for adjusting impedance matching.

6. The cooling fan antenna according to claim 1 or 2, characterized in that, The cooling fan antenna is a planar inverted F-shaped antenna or a short-circuited monopole antenna.

7. The cooling fan antenna according to claim 1 or 2, characterized in that, The cooling fan antenna is a wireless local area network antenna operating at 2.4GHz, 5GHz, and 6GHz.

8. The cooling fan antenna according to claim 1 or 2, characterized in that, The scattering parameter S11 of the cooling fan antenna in the operating frequency range of 2.4GHz, 5GHz and 6GHz meets the specification of -3dB.

9. The cooling fan antenna according to claim 1 or 2, characterized in that, The first opening is an air inlet, and the second opening is an air outlet.

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