A dual-band antenna structure

Abstract

The present invention relates to the technical field of communication antennas, and discloses a dual-band antenna structure. By adopting the form of short-circuit wall loading, the antenna area is reduced; by selecting an appropriate multi-layer dielectric substrate, the antenna bandwidth is expanded and the antenna profile is reduced; by using dual-port feeding, each port corresponds to an opposing frequency band, enabling the two frequency bands to be independently adjusted and radiated. At the same time, this design is applicable to most radio frequency front-end architectures, and the antenna can be directly connected to the output signal of the radio frequency front-end module without a combiner; by combining traditional matching methods and lumped element matching methods, extremely high antenna space utilization is achieved; it has the advantages of small size, low profile, and simple structure, and has good prospects in application fields such as intelligent mobile terminals and intelligent devices.

Description

Technical Field

[0001] The present invention relates to the technical field of communication antennas, and particularly to a dual-band antenna structure. Background Art

[0002] With the rapid development of mobile communication technology, WiFi has become the most widely used wireless transmission technology at present due to its characteristics such as high-speed transmission and convenient use, and is indispensable for modern mobile terminal devices. For modern 5G mobile terminals, on the one hand, the newly introduced frequency bands and high MIMO specifications in 5G have caused a sharp increase in the number of antennas. On the other hand, the metal frame is currently under great pressure because it is covered with antennas. In addition, larger batteries, cameras, screens, and even speakers will squeeze the frame space. These two aspects make it an urgent need to explore new spaces for terminal antennas. The terminal back cover is a space that has been ignored for decades, and it can provide a large area for patch antennas. Therefore, the contradiction between the increasing number of antennas and the decreasing frame space has intensified the demand for small-sized patch antennas.

[0003] According to the IEEE 802.11b / g and IEEE 802.11a protocol standards, the low-frequency operating range of WiFi 6 is 2.4 - 2.5 GHz, and the relative bandwidth is 4.1%. The high-frequency operating range is 5.15 - 5.85 GHz, and the relative bandwidth is 12.7%. Among them, the low-frequency relative bandwidth is about 3 times that of the high-frequency relative bandwidth, which means that the two frequency bands are extremely unbalanced. Currently, most existing dual-band Wi-Fi 6 patch antennas have problems such as an overly wide low-frequency bandwidth or an overly narrow high-frequency bandwidth, and cannot accurately cover these two frequency bands, that is, the -10 dB impedance bandwidth is exactly 2.4 - 2.5 GHz and 5.15 - 5.85 GHz. If there are extra frequencies, it means that the antenna volume is not fully occupied and it may be miniaturized. This is not desirable for modern mobile terminals with precious internal space.

[0004] Common WiFi dual-band antennas often complete the simultaneous feeding of 2.4G / 5G dual bands through a single feeding node. However, since the two frequency bands are not in a multiple-frequency relationship, problems such as unbalanced radiation frequency bands and antenna performance will occur. In addition, since the 2.4 GHz and 5 GHz frequency bands are far apart, the signals of the two frequency bands obtained by the radio frequency front-end module need to be combined together through a combiner and then transmitted to the antenna port, which introduces combiner loss and deteriorates the system performance. Therefore, how to reduce the system cost, reduce the antenna volume under limited space conditions, and at the same time easily adjust the frequency points and bandwidths of the dual band is the key point to be improved in the present invention. Summary of the Invention

[0005] In order to overcome the defects existing in the above-mentioned prior art, the object of the present invention is to provide a dual-band antenna structure to solve the technical problems in the prior art that the antenna cannot cover the unbalanced dual-frequency bands, the control of the frequency and bandwidth of the high and low frequencies is low, and the space utilization rate is not high.

[0006] The present invention is realized through the following technical solutions:

[0007] A dual-band antenna structure includes a radiation patch, a dielectric substrate, a plurality of short-circuit metal posts, a metal floor, a first metal feeding probe, a second metal feeding probe, a first matching module, and a second matching module; the radiation patch is attached to the dielectric substrate, the plurality of short-circuit metal posts are arranged in parallel side by side, and one end of each of them penetrates through the metal floor, and the other end penetrates through the dielectric substrate and is connected to the radiation patch to form an electric field zero point; there is a gap between the dielectric substrate and the metal floor to form an air layer; the first matching module and the second matching module are both arranged on the metal floor, one end of the first metal feeding probe is assembled on the first matching module, and the other end penetrates through the dielectric substrate and is connected to the radiation patch to excite the low-frequency band of the antenna; one end of the second metal feeding probe is assembled on the second matching module, and the other end penetrates through the dielectric substrate and is connected to the radiation patch to excite the high-frequency band of the antenna.

[0008] Preferably, a plurality of short-circuit metal posts penetrate through one side of the dielectric substrate side by side and are connected to one side of the radiation patch, and the side of the radiation patch close to the plurality of short-circuit metal posts is the first side to form an electric field zero point.

[0009] Further, the position of the first matching module on the metal floor corresponds to the longitudinal center line position of the first side of the radiation patch, one end of the first metal feeding probe is assembled on the first matching module, and the other end penetrates through the dielectric substrate and is connected to the longitudinal center line position of the first side of the radiation patch to excite the low-frequency band of the antenna.

[0010] Preferably, the side of the radiation patch perpendicular to the first side is the second side, the position of the second matching module on the metal floor corresponds to the position of the second side of the radiation patch, one end of the second metal feeding probe is assembled on the second matching module, and the other end penetrates through the dielectric substrate and is connected to the position of the second side of the radiation patch to excite the high-frequency band of the antenna.

[0011] Preferably, one end of the first metal feeding probe is assembled on the first matching module, and the other end penetrates through the dielectric substrate and is connected to the radiation patch to excite the low-frequency band of the antenna as the 2.4G band; one end of the second metal feeding probe is assembled on the second matching module, and the other end penetrates through the dielectric substrate and is connected to the radiation patch to excite the high-frequency band of the antenna as the 5G band.

[0012] Preferably, a first matching groove is provided on the metal floor, and the first matching module is assembled in the first matching groove. The first matching module includes a first metal feeding probe patch and a first rectangular patch. The first metal feeding probe patch is attached in the first matching groove and connected to one end of the first metal feeding probe. The first rectangular patch is attached in the first matching groove and is disposed close to the first metal feeding probe patch. A first port is formed between one side of the first rectangular patch and the side wall of the first matching groove. The other side of the first rectangular patch is connected to the first metal feeding probe patch through a second capacitor C2. One side of the first metal feeding probe patch is connected to the side wall of the first matching groove through a first capacitor C1.

[0013] Further, lumped elements are soldered on the first rectangular patch and the first metal feeding probe patch close to the first rectangular patch side.

[0014] Preferably, a second matching groove is provided on the metal floor, and the second matching module is assembled in the second matching groove. The second matching module includes a second metal feeding probe patch, a second rectangular patch, and a third rectangular patch. The second metal feeding probe patch is attached in the second matching groove and connected to one end of the second metal feeding probe. The second rectangular patch and the third rectangular patch are both attached in the first matching groove. A second port is formed between the third rectangular patch and the side wall of the second matching groove. A third capacitor C3 is disposed between the third rectangular patch and the second rectangular patch. A second inductor L2 is disposed between one side of the second rectangular patch and the side wall of the second matching groove. A first inductor Lsh and a fourth capacitor Csh are connected in parallel between the other side of the second rectangular patch and the second metal feeding probe patch.

[0015] Further, the first inductor Lsh and the fourth capacitor Csh form a parallel resonance circuit between the other side of the second rectangular patch and the second metal feeding probe patch. The resonance frequency of the parallel resonance circuit is f 0 = 1 / 2Π(LC) 1 / 2 , where when C×L remains unchanged, the bandwidth of the isolation degree formed by it is related to the Q value of this circuit. The larger the Q value, the narrower the isolation degree bandwidth.

[0016] Preferably, the areas of the radiation patch and the dielectric substrate are correspondingly set.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] The present invention provides a dual - frequency antenna structure. By adopting the form of short - circuit wall loading, the antenna area is reduced. By selecting an appropriate multi - layer dielectric substrate, the antenna bandwidth is expanded and the antenna profile is reduced. By using dual - port feeding, each port corresponds to an opposing frequency band, enabling the two frequency bands to be independently adjusted and radiated. At the same time, this design is applicable to most radio - frequency front - end architectures, and the antenna can be directly connected to the output signal of the radio - frequency front - end module without a combiner. By combining traditional matching methods and lumped - element matching methods, extremely high antenna space utilization is achieved. It has the advantages of small size, low profile, and simple structure, and has good prospects in application fields such as intelligent mobile terminals and intelligent devices.

[0019] Further, on one side of the radiation patch near several short - circuit metal posts, a first side forms an electric - field zero point, enabling the patch antenna to operate in the TM 0.5,0 mode, which can not affect the characteristics of the antenna mode, but the size of the antenna is reduced by half, achieving the miniaturization of the antenna.

[0020] Further, one end of the first metal feeding probe is assembled on the first matching module, and the other end penetrates the dielectric substrate and is connected to the longitudinal center - line position of the first side of the radiation patch to excite the low - frequency band of the antenna, exciting the TM 0.5,0 mode of the antenna. At the same time, it is located at the zero point of the TM 0.5,1 mode, avoiding exciting the TM 0.5,1 mode. Its position can be changed. The closer it is to the first side, the wider the antenna bandwidth and the higher the radiation efficiency.

[0021] Further, the side perpendicular to the first side on the radiation patch is the second side. The second matching module is located at the position corresponding to the second side of the radiation patch on the metal floor. One end of the second metal feeding probe is assembled on the second matching module, and the other end penetrates the dielectric substrate and is connected to the position of the second side of the radiation patch to excite the high - frequency band of the antenna. The distance of the second metal feeding probe from the first side and the distance from the second side can be adjusted. Both its distance from the first side and the distance from the second side can be changed. The closer it is to the first side, the wider the antenna bandwidth and the higher the radiation efficiency; the closer it is to the second side, the better the isolation from the port. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a side view of the dual - frequency antenna structure in the present invention;

[0023] Figure 2 It is a top view of the radiation patch of the dual - frequency antenna structure in the present invention;

[0024] Figure 3 It is a top view of the metal floor of the dual - frequency antenna structure in the present invention;

[0025] Figure 4 Details diagram of the 2.4G matching module of the dual-band antenna in the present invention;

[0026] Figure 5 Details diagram of the 5G matching module of the dual-band antenna in the present invention;

[0027] Figure 6 Schematic diagram of the return loss curve of the dual-band antenna in the present invention;

[0028] Figure 7 Schematic diagram of the total efficiency curve of the dual-band antenna in the present invention;

[0029] Figure 8 Schematic diagram of the E-plane pattern of the 2.4G port of the dual-band antenna at 2.45GHz in the present invention;

[0030] Figure 9 Schematic diagram of the H-plane pattern of the 2.4G port of the dual-band antenna at 2.45GHz in the present invention;

[0031] Figure 10 Schematic diagram of the E-plane pattern of the 5G port of the dual-band antenna at 5.5GHz in the present invention;

[0032] Figure 11 Schematic diagram of the H-plane pattern of the 5G port of the dual-band antenna at 5.5GHz in the present invention.

[0033] In the figure: 1 - radiation patch; 2 - dielectric substrate; 3 - air layer; 4 - shorting metal post; 5 - metal floor; 6 - first metal feeding probe; 7 - second metal feeding probe; 8 - first side; 9 - second side; 10 - first matching module; 11 - second matching module; 12 - first matching slot; 13 - first metal feeding probe patch; 14 - first rectangular patch; 15 - first port; 16 - second matching slot; 17 - second metal feeding probe patch; 18 - second rectangular patch; 19 - third rectangular patch; 20 - second port; C1 - first capacitor; C2 - second capacitor; C3 - third capacitor; Csh - fourth capacitor; Lsh - first inductor; L2 - second inductor. Detailed implementation manners

[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0035] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0036] The present invention will be further described in detail below with reference to the accompanying drawings:

[0037] The object of the present invention is to provide a dual-band antenna structure to solve the technical problems in the prior art that the antenna cannot cover unbalanced dual-frequency bands, the control of the frequency and bandwidth of high and low frequencies is low, and the space utilization rate is not high.

[0038] Specifically, according to Figure 1 、 Figure 2 and Figure 3 shown, the dual-band antenna structure includes a radiation patch 1, a dielectric substrate 2, a plurality of short-circuit metal posts 4, a metal floor 5, a first metal feeding probe 6, a second metal feeding probe 7, a first matching module 10 and a second matching module 11; the radiation patch 1 is attached to the dielectric substrate 2, and a plurality of short-circuit metal posts 4 are arranged in parallel side by side, and one end of each of them penetrates through the metal floor 5, and the other end penetrates through the dielectric substrate 2 and is connected to the radiation patch 1 to form an electric field zero point; there is a gap between the dielectric substrate 2 and the metal floor 5 to form an air layer 3; the first matching module 10 and the second matching module 11 are both arranged on the metal floor 5, one end of the first metal feeding probe 6 is assembled on the first matching module 10, and the other end penetrates through the dielectric substrate 2 and is connected to the radiation patch 1 to excite the low-frequency band of the antenna; one end of the second metal feeding probe 7 is assembled on the second matching module 11, and the other end penetrates through the dielectric substrate 2 and is connected to the radiation patch 1 to excite the high-frequency band of the antenna.

[0039] Specifically, a plurality of short-circuit metal posts 4 penetrate through one side of the dielectric substrate 2 side by side and are connected to one side of the radiation patch 1, and the side of the radiation patch 1 close to the plurality of short-circuit metal posts 4 is the first side 8 to form an electric field zero point.

[0040] Among them, the first matching module 10 is located at the position corresponding to the longitudinal center line of the first side 8 of the radiation patch 1 at the position of the metal floor 5. One end of the first metal feeding probe 6 is assembled on the first matching module 10, and the other end penetrates through the dielectric substrate 2 and is connected to the position of the longitudinal center line of the first side 8 of the radiation patch 1 to excite the low-frequency band of the antenna.

[0041] Specifically, one side of the radiation patch 1 perpendicular to the first side 8 is the second side 9. The second matching module 11 is located at the position corresponding to the second side 9 of the radiation patch 1 at the position of the metal floor 5. One end of the second metal feeding probe 7 is assembled on the second matching module 11, and the other end penetrates through the dielectric substrate 2 and is connected to the position of the second side 9 of the radiation patch 1 to excite the high-frequency band of the antenna.

[0042] Specifically, one end of the first metal feeding probe 6 is assembled on the first matching module 10, and the other end penetrates through the dielectric substrate 2 and is connected to the radiation patch 1 to excite the low-frequency band of the antenna, which is the 2.4G band; one end of the second metal feeding probe 7 is assembled on the second matching module 11, and the other end penetrates through the dielectric substrate 2 and is connected to the radiation patch 1 to excite the high-frequency band of the antenna, which is the 5G band.

[0043] Specifically, according to Figure 4 As shown, a first matching groove 12 is provided on the metal floor 5. The first matching module 10 is assembled in the first matching groove 12. The first matching module 10 includes a first metal feeding probe patch 13 and a first rectangular patch 14. The first metal feeding probe patch 13 is attached in the first matching groove 12 and is connected to one end of the first metal feeding probe 6. The first rectangular patch 14 is attached in the first matching groove 12 and is disposed close to the first metal feeding probe patch 13. A first port 15 is formed between one side of the first rectangular patch 14 and the side wall of the first matching groove 12. The other side of the first rectangular patch 14 is connected to the first metal feeding probe patch 13 through a second capacitor C2. One side of the first metal feeding probe patch 13 is connected to the side wall of the first matching groove 12 through a first capacitor C1.

[0044] Among them, lumped elements are soldered on the first rectangular patch 14 and the first metal feeding probe patch 13 close to the first rectangular patch 14 side.

[0045] Specifically, according to Figure 5As shown in the figure, a second matching groove 16 is provided on the metal floor 5, and the second matching module 11 is assembled in the second matching groove 16. The second matching module 11 includes a second metal feeding probe patch 17, a second rectangular patch 18, and a third rectangular patch 19. The second metal feeding probe patch 17 is attached to the second matching groove 16 and is connected to one end of the second metal feeding probe 7. The second rectangular patch 18 and the third rectangular patch 19 are both attached to the first matching groove 12. A second port 20 is provided between the third rectangular patch 19 and the side wall of the second matching groove 16. A third capacitor C3 is provided between the third rectangular patch 19 and the second rectangular patch 18. A second inductor L2 is provided between one side of the second rectangular patch 18 and the side wall of the second matching groove 16. A first inductor Lsh and a fourth capacitor Csh are connected in parallel between the other side of the second rectangular patch 18 and the second metal feeding probe patch 17.

[0046] Among them, the first inductor Lsh and the fourth capacitor Csh form a parallel resonance circuit between the other side of the second rectangular patch 18 and the second metal feeding probe patch 17. The resonance frequency of the parallel resonance circuit is f0 = 1 / 2Π(LC) 1 / 2 = 2.4 GHz.

[0047] Specifically, the areas of the radiation patch 1 and the dielectric substrate 2 are correspondingly set.

[0048] Embodiment

[0049] The present invention provides a micro antenna. The microstrip antenna includes a metal floor 5, an air layer 3, a plurality of short - circuit metal columns 4, a dielectric substrate 2, and a radiation patch 1 from bottom to top. Among them, the first matching module 10 and the second matching module 11 are provided in the metal floor 5. The first matching module 10 is a 2.4G matching module, and the second matching module 11 is a 5G matching module.

[0050] As Figure 1As shown, in this embodiment, the longitudinal length and the transverse length of the metal floor 5 are both set to 100 mm. Since the metal floor 5 does not participate in antenna radiation, this value can be set arbitrarily, and the shape can also be changed, which does not affect the antenna performance, but it is required to be able to completely place the 2.4G matching module and the 5G matching module. The material of the dielectric substrate 2 is FR-4, the dielectric constant is 4.3, and the thickness is 0.5 mm. Any other material that can be used as an antenna substrate is applicable to the present invention and is not limited to this embodiment. The transverse length of the dielectric substrate 2 is set to 23.45 mm, and the longitudinal length is set to 24.35 mm. The thickness of the air layer 3 is set to 2.5 mm. By using the method of placing the air layer 3 under the dielectric substrate 2, the system Q value can be reduced and the impedance bandwidth of the antenna can be expanded. The material of several short-circuit metal posts 4 is copper, the radius is set to 0.3 mm, and its height is the sum of the heights of the air layer 3 and the dielectric substrate 2, which is 3 mm here. It can be seen that the antenna profile in this embodiment is low and the size is small.

[0051] As Figure 2 shown, several short-circuit metal posts 4, the first metal feeding probe patch 6 and the second metal feeding probe 7 are distributed on the radiation patch 1. The short-circuit wall of the dual-band antenna is composed of vertical short-circuit metal posts 4. Among them, the first metal feeding probe patch 6 is a 2.4G metal feeding probe, and the second metal feeding probe 7 is a 5G metal feeding probe.

[0052] Specifically, due to the symmetry of the main mode TM10 mode of the patch antenna, several short-circuit metal posts 4 artificially construct an electric field zero point on the first side 8, so that the patch antenna operates in the TM 0.5,0 mode. In this way, the characteristics of the antenna mode can be not affected, but the size of the antenna is reduced by half, realizing the miniaturization of the antenna. The 2.4G metal feeding probe is located at the center line position of the longitudinal direction of the radiation patch 1. Its purpose is to excite the TM 0.5,0 mode of the antenna, and at the same time, it is located at the zero point of the TM 0.5,1 mode to avoid exciting the TM 0.5,1 mode. Its position can be changed. The closer it is to the first side 8, the wider the antenna bandwidth and the higher the radiation efficiency. The distance between the 2.4G metal feeding probe and several short-circuit metal posts 4 on its upper and lower sides is set to 2.5 mm. This distance can adjust the relationship between the radiation efficiency and the impedance bandwidth at the 2.4 GHz frequency band. The smaller this value is, the wider the bandwidth and the lower the radiation efficiency. The distance between the 5G metal feeding probe and the first side 8 is set to 4 mm, and the distance from the second side 9 is set to 0.5 mm. The distances from the first side 8 and the second side 9 can both be changed. The closer it is to the first side 8, the wider the antenna bandwidth and the higher the radiation efficiency; the closer it is to the second side 9, the better the isolation from the port 1.

[0053] As Figure 3 , Figure 4 and Figure 5As shown, there are a 2.4G matching module and a 5G matching module on the metal floor 5. The working principles of the two matching modules are similar, and the similar principle parts will not be repeated here. The two matching modules mainly rely on lumped elements to adjust the impedance matching and isolation degree between the first port 17 (2.4G port) and the second port 20 (5G port).

[0054] The 2.4G matching module 10 is separated from the metal floor 5 by the first matching slot 12. The first matching slot 12 is engraved on the floor to be separated from the metal floor 5. The shape of this slot can be arbitrary, but it needs to be able to complete the structure required for matching. The shape adopted here is a combination of a semi-circular slot with a radius of 0.75 mm and a rectangular slot with a length of 2.15 mm and a width of 1.5 mm. The 2.4G metal feeding probe is connected to the first metal feeding probe patch 13, and its radius is set to 0.4 mm for easy connection with the 2.4G metal feeding probe. The transverse length of the connected rectangular slot is set to 0.8 mm. The length and width of the first rectangular patch 14 are set to 0.8 mm and 0.5 mm respectively. The two rectangular patch parts are used to connect the first capacitor C1 and the second capacitor C2 into the matching structure, and the distance between them is set to 0.35 mm, which can just weld the lumped elements of the 0402 model. The lengths and gaps set above are all based on the dimensions of the lumped elements of the 0402 model, and these values can be changed according to the component model. For the first capacitor C1, its two pins are respectively placed on the rectangular slot and the metal floor 5. For the capacitor C2, its two pins are respectively placed on the rectangular slot and the first rectangular patch 14. The capacitor C1 is set to 1.3 pF, and the capacitor C2 is set to 1.1 pF. Here, the two capacitors are used to match the first port 15. The values of the first capacitor C1 and the second capacitor C2 can be changed according to different frequency bands, as long as the other port is matched.

[0055] The shape of the second matching slot 16 in the 5G matching module can be arbitrary. Here, it is formed by a combination of a semi-circular slot with a radius of 0.75 mm and a rectangular slot with a length of 3.4 mm and a width of 1.5 mm. The longitudinal length of the second metal feeding probe patch 19 is 0.7 mm. The values of the capacitor Csh and the inductor Lsh are set to 0.5 pF and 8.7 nH respectively. Its two pins are respectively placed on the second metal feeding probe patch 19 and the second rectangular patch 18. The resonant frequency f0 of this parallel resonant circuit is f0 = 1 / 2Π(LC)1 / 2 = 2.4 GHz. Therefore, it can prevent the energy of the first port 15 (2.4G port) from being transmitted to the second port 20 (5G port). Because the second metal feeding probe 7 is not located in the TM excited by the first metal feeding probe 6 0.5,0At the zero point of the electric field in the mode, part of the energy will flow in. Next, a second inductor L2 with a value of 3.4 nH is connected in parallel, and finally a third capacitor C3 with a value of 0.31 pF is connected in series. They jointly play a role in impedance matching. The setting method of the rectangular patch value here is similar to that of the 2.4G matching module.

[0056] Based on the above design process, the design process of the antenna designed using this method is as follows: First, select an appropriate size of the radiation patch. The length and width of the radiation patch respectively determine the natural resonance frequencies generated by the two modes. The natural resonance frequency refers to the resonance frequency generated when the feeding probe is placed at the point where the antenna input impedance is 50 Ω. The designed dual-frequency points are obtained by adjusting the length and width of the radiation patch. Second, select an appropriate position for the feeding probe. Different positions of the feeding probe correspond to different impedance trajectories on the Smith chart. The smaller the impedance trajectory, the wider the antenna bandwidth. Optimize the feeding position to obtain the maximum bandwidth of the antenna. Finally, add a matching module. The lumped element matching method can be used to achieve good matching for the two resonance points.

[0057] The CST software is used to test the performance of this preferred embodiment. Figure 6 This is the schematic diagram of the return loss curve of this preferred embodiment. It can be seen from the figure that the operating frequency band of the 2.4G port is 2.4 - 2.5 GHz, which exactly covers the low-frequency band of WiFi; the operating frequency band of the 5G port is 5.15 - 5.85 GHz, which exactly covers the high-frequency band of WiFi. The isolation between the two ports can reach 30 dB within the operating frequency band, and the bandwidth and operating frequency band of the two ports can be adjusted relatively independently. Figure 7 This is the schematic diagram of the total efficiency curve of this preferred embodiment. It can be seen from the figure that the total efficiency of the antenna is greater than -1.65 dB within the operating frequency band. Figure 8 、 Figure 9 、 Figure 10 and Figure 11 These are the E-plane and H-plane radiation patterns of this preferred embodiment at different frequency bands. When the antenna is at 2.45 GHz, the gain is 4.4 dBi, and when it is at 5.5 GHz, the gain is 8.56 dBi.

[0058] The present invention can have various deformation methods. For example, changing the dielectric substrate material can further reduce the antenna height, and changing the length of the radiation patch and the values of the lumped elements in the matching module can make the antenna operate in other frequency bands, etc. The various parameters proposed in the present invention can be adjusted on the premise of achieving impedance matching.

[0059] Compared with the prior art, this preferred embodiment adopts the form of vertical short-circuit metal column loading to reduce the antenna area; by adding an air layer structure, the antenna Q value is reduced, the antenna impedance bandwidth is expanded, and the antenna profile is reduced; by using the TM 0.5,0 mode and TM0.5,1 The mode enables the two ports to work on the 2.4G band and 5G band of WiFi respectively; by loading lumped elements and properly selecting the feeding points, the two ports of the antenna exactly cover the WiFi dual-band completely, making full use of the volume of the antenna.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the specific implementation manners of the present invention can still be modified or equivalently replaced, and any modification or equivalent replacement without departing from the spirit and scope of the present invention shall be covered by the protection scope of the claims of the present invention.

Claims

1. A dual - frequency antenna structure, characterized in that, it includes a radiation patch (1), a dielectric substrate (2), several short - circuit metal posts (4), a metal floor (5), a first metal feeding probe (6), a second metal feeding probe (7), a first matching module (10) and a second matching module (11); the radiation patch (1) is attached to the dielectric substrate (2), several short - circuit metal posts (4) are arranged in parallel side by side, and one end of each of them penetrates through the metal floor (5) and the other end penetrates through the dielectric substrate (2) and is connected to the radiation patch (1) to form an electric - field zero point; there is a gap between the dielectric substrate (2) and the metal floor (5) to form an air layer (3); both the first matching module (10) and the second matching module (11) are arranged on the metal floor (5), one end of the first metal feeding probe (6) is assembled on the first matching module (10), and the other end penetrates through the dielectric substrate (2) and is connected to the radiation patch (1) to excite the low - frequency band of the antenna; one end of the second metal feeding probe (7) is assembled on the second matching module (11), and the other end penetrates through the dielectric substrate (2) and is connected to the radiation patch (1) to excite the high - frequency band of the antenna; several short - circuit metal posts (4) penetrate through one side of the dielectric substrate (2) side by side and are connected to one side of the radiation patch (1), and on the radiation patch (1), the side close to several short - circuit metal posts (4) is the first side (8) to form an electric - field zero point.

2. The dual - frequency antenna structure according to claim 1, characterized in that, the position of the first matching module (10) on the metal floor (5) corresponds to the longitudinal center - line position of the first side (8) of the radiation patch (1), one end of the first metal feeding probe (6) is assembled on the first matching module (10), and the other end penetrates through the dielectric substrate (2) and is connected to the longitudinal center - line position of the first side (8) of the radiation patch (1) to excite the low - frequency band of the antenna.

3. The dual - frequency antenna structure according to claim 1, characterized in that, the side of the radiation patch (1) perpendicular to the first side (8) is the second side (9), the position of the second matching module (11) on the metal floor (5) corresponds to the position of the second side (9) of the radiation patch (1), one end of the second metal feeding probe (7) is assembled on the second matching module (11), and the other end penetrates through the dielectric substrate (2) and is connected to the position of the second side (9) of the radiation patch (1) to excite the high - frequency band of the antenna.

4. The dual - frequency antenna structure according to claim 1, characterized in that, one end of the first metal feeding probe (6) is assembled on the first matching module (10), and the other end penetrates through the dielectric substrate (2) and is connected to the radiation patch (1) to excite the low - frequency band of the antenna as the 2.4G band; one end of the second metal feeding probe (7) is assembled on the second matching module (11), and the other end penetrates through the dielectric substrate (2) and is connected to the radiation patch (1) to excite the high - frequency band of the antenna as the 5G band.

5. The dual - frequency antenna structure according to claim 1, characterized in that, The metal floor (5) is provided with a first matching groove (12), and the first matching module (10) is assembled in the first matching groove (12). The first matching module (10) includes a first metal feeding probe patch (13) and a first rectangular patch (14); the first metal feeding probe patch (13) is attached in the first matching groove (12) and connected to one end of the first metal feeding probe (6). The first rectangular patch (14) is attached in the first matching groove (12) and is disposed close to the first metal feeding probe patch (13). A first port (15) is formed between one side of the first rectangular patch (14) and the side wall of the first matching groove (12). The other side of the first rectangular patch (14) is connected to the first metal feeding probe patch (13) through a second capacitor C2, and one side of the first metal feeding probe patch (13) is connected to the side wall of the first matching groove (12) through a first capacitor C1.

6. The dual-frequency antenna structure according to claim 5, wherein, lumped elements are welded on the first rectangular patch (14) and the first metal feeding probe patch (13) close to the first rectangular patch (14).

7. The dual-frequency antenna structure according to claim 1, wherein, The metal floor (5) is provided with a second matching groove (16), and the second matching module (11) is assembled in the second matching groove (16). The second matching module (11) includes a second metal feeding probe patch (17), a second rectangular patch (18) and a third rectangular patch (19); the second metal feeding probe patch (17) is attached in the second matching groove (16) and connected to one end of the second metal feeding probe (7). The second rectangular patch (18) and the third rectangular patch (19) are both attached in the first matching groove (12). A second port (20) is formed between the third rectangular patch (19) and the side wall of the second matching groove (16). A third capacitor C3 is disposed between the third rectangular patch (19) and the second rectangular patch (18). A second inductor L2 is disposed between one side of the second rectangular patch (18) and the side wall of the second matching groove (16). A first inductor Lsh and a fourth capacitor Csh are connected in parallel between the other side of the second rectangular patch (18) and the second metal feeding probe patch (17).

8. The dual-frequency antenna structure according to claim 7, wherein, The first inductor Lsh and the fourth capacitor Csh form a parallel resonant circuit between the other side of the second rectangular patch (18) and the second metal feeding probe patch (17), where the resonant frequency of the parallel resonant circuit is f 0 = 1 / 2Π(LC) 1 / 2 , where, when C×L remains unchanged, the bandwidth of the formed isolation degree is related to the Q value of this circuit. The larger the Q value, the narrower the isolation degree bandwidth.

9. The dual-frequency antenna structure according to claim 1, wherein, the areas of the radiation patch (1) and the dielectric substrate (2) are correspondingly set.

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