A composite 5g antenna applied to a portable wi-fi and an application method thereof

Abstract

The application discloses a composite 5G antenna applied to a portable WiFi and an application method thereof, which comprises a first antenna and a second antenna, the first antenna and the second antenna are both installed on an antenna support in a shell of a portable WiFi device, the first antenna comprises a first radiator, a feed spring, two ground spring and a coaxial cable II, and the second antenna comprises a second radiator and a coaxial cable I. In the application, the second antenna is parasitic on the ground spring of the first antenna, the independent ground structure of the second antenna is omitted, the occupied space of the antenna in the portable WiFi device is remarkably reduced, the space utilization of the device is high, the design requirement of miniaturization is adapted, and the electromagnetic coupling between the two antennas is effectively optimized by arranging a fold line structure at the ground position of the second antenna. In a same-frequency working scene, the isolation degree can reach above 15 dB, signal interference is avoided, the isolation degree is excellent, communication stability is improved, and multi-scene communication is adapted.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, specifically to a composite 5G antenna for portable WiFi and its application method. Background Technology

[0002] With the development of 5G communication technology, the use of portable WiFi is gradually being promoted. Portable WiFi is a portable network device that can convert mobile network, wired broadband and other signals into WiFi hotspots for multiple devices such as mobile phones and tablets to share the Internet. Its core value lies in solving the network needs in mobile scenarios. Depending on the signal source, it can be divided into card-type portable WiFi and shared portable WiFi. As a portable network access device, current portable WiFi devices need to support multi-band (such as N1, N3, N28, N41, N78, N79) communication to meet the network needs in different scenarios.

[0003] Current portable WiFi devices are small in size and have extremely limited internal space. In traditional designs, multiple antennas are usually arranged independently, meaning each antenna has its own radiator and grounding structure. This not only occupies a lot of space but is also prone to co-channel interference due to insufficient antenna spacing, making it difficult to improve isolation and affecting communication performance. In existing technologies, some solutions save space by shortening the antenna size or optimizing the shape of the radiator, but this often leads to narrower antenna bandwidth and reduced gain. Other solutions use parasitic branches to improve isolation, but these are mostly for specific frequency bands and are difficult to adapt to the multi-frequency band requirements of 5G. Summary of the Invention

[0004] This invention provides a composite 5G antenna for portable WiFi and its application method, which can effectively solve the problems mentioned in the background art. Current portable WiFi devices are small in size and have extremely limited internal space. In traditional designs, multiple antennas are usually arranged independently, that is, each antenna has an independent radiator and grounding structure. This not only occupies a lot of space, but is also prone to co-channel interference due to insufficient antenna spacing, making it difficult to improve isolation and affecting communication performance. In the prior art, some solutions save space by shortening the antenna size or optimizing the shape of the radiator, but this often leads to narrower antenna bandwidth and reduced gain. Other solutions use parasitic branches to improve isolation, but these are mostly for specific frequency bands and are difficult to adapt to the multi-frequency band requirements of 5G.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a composite 5G antenna for portable WiFi, comprising a first antenna and a second antenna, both the first antenna and the second antenna being mounted on an antenna bracket inside the housing of the portable WiFi device; the first antenna comprising a first radiator, a feed spring, two grounding springs and a second coaxial cable; and the second antenna comprising a second radiator and a first coaxial cable.

[0006] A motherboard is installed on one side of the top of the portable WiFi device housing, and a 5G module is installed on the other side of the top of the portable WiFi device housing. A grounding solder point is provided on the inner side of the second antenna, and a power supply solder point is provided on the inner side of the second antenna next to the grounding solder point. The power supply solder point is connected to the antenna interface one on the 5G module through a coaxial cable one. An antenna interface two is provided on the side of the 5G module next to the antenna interface one, and a coaxial cable two is connected to the antenna interface two.

[0007] The first antenna has a feeding spring inside, and grounding springs are provided on both sides of the feeding spring. The feeding spring is connected to the antenna RF connector of the 5G module via a 50-ohm impedance transmission line through a coaxial cable.

[0008] The second antenna uses the grounding spring of the first antenna as its own grounding reference, that is, the ground of the second antenna is the grounding spring of the first antenna, and the second radiator of the second antenna is arranged adjacent to the grounding spring of the first antenna to form a parasitic coupling structure.

[0009] According to the above technical solution, the first radiator of the first antenna is used to receive 5G frequency band signals, specifically including the N28, N3, N1, N41, N78, and N79 frequency bands.

[0010] The second radiator of the second antenna is used to receive and transmit 5G frequency band signals, specifically receiving 5G frequency band signals in band N1, and transmitting and receiving 5G frequency band signals in bands N41, N78, and N79.

[0011] According to the above technical solution, the grounding position of the second antenna, that is, the connection area between the second radiator of the second antenna and the grounding spring of the first antenna, is provided with a broken line structure.

[0012] According to the above technical solution, the parasitic coupling structure refers to the grounding spring of the first antenna serving as the ground of the second antenna, which is equivalent to the second antenna being parasitic on the first antenna. The adjacent distance between the second radiator of the second antenna and the grounding spring of the first antenna is 5-15mm.

[0013] According to the above technical solution, both antenna interface one and antenna interface two are set on the antenna RF connector of the 5G module.

[0014] According to the above technical solution, both the grounding spring and the power supply spring are made of conductive materials, specifically copper, silver, or alloy, and both the grounding spring and the power supply spring are connected to the grounding terminal of the motherboard of the portable WiFi device.

[0015] According to the above technical solution, the broken line structure is used to adjust the impedance matching of the second antenna and the isolation from the first antenna. The broken line structure improves the low-frequency isolation by increasing the ground wire length and improves the bandwidth and efficiency through gap coupling.

[0016] An application method for a composite 5G antenna for portable WiFi includes the following steps:

[0017] Step 1: Antenna assembly and layout;

[0018] Step 2, circuit connection configuration;

[0019] Step 3: Electrical connection and commissioning;

[0020] Step four: Equipment integration and packaging.

[0021] According to the above technical solution, in step one, before antenna assembly, it is necessary to confirm the installation position of the reserved antenna bracket inside the housing of the portable WiFi device, and ensure that the size of the antenna bracket matches the structure between the first antenna and the second antenna, so as to satisfy the parasitic layout between the first antenna and the second antenna.

[0022] During the assembly process, the first antenna and the second antenna 2 are installed on the antenna brackets pre-set inside the housing of the portable WiFi device, and the positions of the first antenna and the second antenna need to be fixed.

[0023] When installing the first antenna, it is necessary to ensure that its two grounding springs are reliably connected to the grounding terminal of the equipment motherboard, and the power supply spring is connected to the RF signal input terminal of the motherboard;

[0024] When installing the second antenna, the second radiator of the second antenna needs to be placed near the grounding spring of the first antenna, with a spacing of 5-15mm between them.

[0025] The grounding connection with the second radiator of the second antenna is achieved through a broken line structure. The broken line structure needs to be pre-designed with a specific shape to optimize the impedance matching of the second antenna and the isolation from the first antenna.

[0026] In step two, during the connection process between the first antenna and the second antenna, the first antenna receives and transmits multi-band signals through the feed spring, including N28, N3, N1, N41, N78, and N79.

[0027] The second antenna is connected to the antenna RF connector of the 5G module via a coaxial cable. It mainly covers the N1 frequency band and works with the first antenna to extend the coverage of the N41, N78, and N79 frequency bands.

[0028] According to the above technical solution, in step three, the feed spring of the first antenna is connected to the antenna RF connector of the 5G module through the second coaxial cable, and the second antenna is indirectly grounded through the parasitic grounding spring. Furthermore, the grounding of the second antenna is indirectly dependent on the grounding spring of the first antenna through the zigzag structure.

[0029] During the specific debugging process, the mainstream 5G frequency bands, including N1, N3, N28, N41, N78, and N79, were switched through the equipment software to verify the signal strength and isolation index of each mainstream frequency band, ensuring that the signal strength is ≥-75dBm;

[0030] The broken line structure is used to ensure an isolation of ≥15dB when operating at the same frequency. In the event of signal abnormality, the geometric parameters of the broken line structure are adjusted to optimize impedance matching so that it matches the impedance of the motherboard RF circuit. This adjustment process needs to be debugged and calibrated during the mass production stage.

[0031] Step four involves potting the pre-installed antenna bracket inside the casing of the portable WiFi device after connection, using low dielectric loss resin for encapsulation.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. By parasitizing the second antenna on the grounding spring of the first antenna, the independent grounding structure of the second antenna is eliminated, which significantly reduces the space occupied by the antenna in the portable WiFi device, making the device space utilization high and adapting to the miniaturization design requirements. Furthermore, by setting a zigzag structure at the grounding position of the second antenna, the electromagnetic coupling between the two antennas is effectively optimized. In the same frequency working scenario, the isolation can reach more than 15dB, avoiding signal interference, with excellent isolation and improving communication stability.

[0034] The first and second antennas cover different 5G frequency bands respectively. When combined, they can meet the transmission and reception needs of portable WiFi devices for mainstream 5G frequency bands such as N1, N3, N28, N41, N78, and N79. They have strong multi-band coverage capabilities and are suitable for communication in various scenarios. In addition, the second antenna adopts a grounding scheme, which reduces the influence of coaxial cable. It can maintain good VSWR and efficiency in each frequency band, ensuring efficient and stable transmission of 5G signals.

[0035] 2. By realizing a multi-band coverage, high isolation, and compact 5G antenna in a miniaturized portable WiFi device, and through an innovative parasitic structure design, efficient transmission and reception of multi-band 5G signals is achieved within the limited space of the portable WiFi device. At the same time, the antenna isolation is improved when operating on the same frequency through a zigzag structure. This effectively solves the problems of large space occupation, low isolation on the same frequency, and difficulty in achieving the performance of multiple bands in existing portable WiFi devices with multi-antenna layouts. It is suitable for portable 5G communication devices such as portable WiFi devices. This composite antenna has the characteristics of compact structure, high isolation, and support for multi-band 5G communication. Attached Figure Description

[0036] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0037] In the attached diagram:

[0038] Figure 1 This is a schematic diagram of the antenna connection and installation of the present invention;

[0039] Figure 2 This is a schematic diagram of the unfolded first and second antennas of the present invention;

[0040] Figure 3 This is a schematic diagram of the actual arrangement of the antenna of the present invention;

[0041] Figure 4 This is a flowchart of the antenna application method of the present invention;

[0042] Figure 5 This is the return loss diagram of the first antenna of the present invention;

[0043] Figure 6 This is the second antenna return loss diagram of this invention;

[0044] Figure 7 This is a graph showing the isolation between the first antenna and the second antenna of the present invention.

[0045] Figure 8 This is a flowchart of the steps for achieving the first antenna efficiency curve in this invention;

[0046] Figure 9 This is a flowchart of the second-stage line efficiency curve of the present invention;

[0047] The diagram is labeled as follows: 1. First antenna; 2. Second antenna; 3. Mainboard; 4. 5G module; 5. Grounding solder joint; 6. Feed solder joint; 7. Antenna interface one; 8. Antenna interface two; 9. Coaxial cable one; 10. Coaxial cable two; 11. Grounding spring; 12. Feed spring; 13. Folded line structure. Detailed Implementation

[0048] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0049] Example: Figure 1-3 As shown, this invention provides a technical solution: a composite 5G antenna for portable WiFi, comprising a first antenna 1 and a second antenna 2. Both the first antenna 1 and the second antenna 2 are mounted on an antenna bracket inside the housing of the portable WiFi device. The first radiator of the first antenna 1 is used to receive 5G frequency band signals, specifically including the N28, N3, N1, N41, N78, and N79 frequency bands. The second radiator of the second antenna 2 is used to receive and transmit 5G frequency band signals, specifically receiving 5G frequency band signal N1. The antenna is designed to transmit and receive 5G frequency bands including N41, N78, and N79. The first antenna 1 and the second antenna 2 cover different 5G frequency bands respectively. When combined, they can meet the transmission and reception needs of portable WiFi devices for mainstream 5G frequency bands such as N1, N3, N28, N41, N78, and N79. It has strong multi-band coverage and is suitable for communication in multiple scenarios. The first antenna 1 includes a first radiator, a feeding spring 12, two grounding springs 11, and a second coaxial cable 10. The second antenna 2 includes a second radiator and a first coaxial cable 9.

[0050] A motherboard 3 is installed on one side of the top of the portable WiFi device housing, and a 5G module 4 is installed on the other side of the top of the portable WiFi device housing. A grounding solder point 5 is provided on the inner side of the second antenna 2. A power supply solder point 6 is provided on the inner side of the second antenna 2 on one side of the grounding solder point 5. The power supply solder point 6 is connected to the antenna interface 7 on the 5G module 4 through a coaxial cable 9. An antenna interface 8 is provided on the side of the 5G module 4 on one side of the antenna interface 7. Both the antenna interface 7 and the antenna interface 8 are provided on the antenna RF connector of the 5G module 4. A coaxial cable 10 is connected to the antenna interface 8.

[0051] The first antenna 1 has a feed spring 12 inside. Both the ground spring 11 and the feed spring 12 are made of conductive material, specifically copper. Both the ground spring 11 and the feed spring 12 are connected to the ground terminal of the motherboard of the portable WiFi device. The second antenna 2 adopts a grounding scheme, which reduces the influence of the coaxial cable and can maintain good VSWR and efficiency in all frequency bands. The feed spring 12 has ground springs 11 on both sides. The feed spring 12 is connected to a 50-ohm impedance transmission line and is connected to the antenna RF connector of the 5G module 4 through a coaxial cable 10.

[0052] The second antenna 2 uses the grounding spring 11 of the first antenna 1 as its own grounding reference. That is, the ground of the second antenna 2 is the grounding spring 11 of the first antenna 1. The parasitic coupling structure means that the grounding spring 11 of the first antenna 1 serves as the ground of the second antenna 2, which is equivalent to the second antenna 2 being parasitic on the first antenna 1. The adjacent distance between the second radiator of the second antenna 2 and the grounding spring 11 of the first antenna 1 is 10mm. By parasitizing the second antenna 2 on the grounding spring 11 of the first antenna 1, the independent grounding structure of the second antenna 2 is eliminated, which significantly reduces the space occupied by the antenna in the portable WiFi device, making the device space utilization high. In addition, the second radiator of the second antenna 2 is set adjacent to the grounding spring 11 of the first antenna 1 to form a parasitic coupling structure.

[0053] The grounding position of the second antenna 2, that is, the connection area between the second radiator of the second antenna 2 and the grounding spring 11 of the first antenna 1, is provided with a broken line structure 13. The broken line structure 13 is used to adjust the impedance matching of the second antenna 2 and the isolation between it and the first antenna 1. The broken line structure 13 improves the low-frequency isolation by increasing the ground wire length and improves the bandwidth and efficiency by using slot coupling. By setting the broken line structure 13 at the grounding position of the second antenna 2, the electromagnetic coupling between the two antennas is effectively optimized. In the same frequency operating scenario, the isolation can reach more than 15dB, avoiding signal interference.

[0054] like Figure 4 As shown, an application method for a composite 5G antenna used in portable WiFi includes the following steps:

[0055] Step 1: Antenna assembly and layout;

[0056] Step 2, circuit connection configuration;

[0057] Step 3: Electrical connection and commissioning;

[0058] Step four: Equipment integration and packaging.

[0059] Based on the above technical solution, in step one, before assembling the antenna, it is necessary to confirm the installation position of the reserved antenna bracket inside the housing of the portable WiFi device, and ensure that the size of the antenna bracket matches the structure between the first antenna 1 and the second antenna 2, so as to satisfy the parasitic layout between the first antenna 1 and the second antenna 2.

[0060] During the assembly process, the first antenna 1 and the second antenna 2 are installed on the antenna brackets pre-set inside the housing of the portable WiFi device. The positions of the first antenna 1 and the second antenna 2 need to be fixed to avoid structural displacement due to device movement.

[0061] When installing the first antenna 1, it is necessary to ensure that its two grounding springs 11 are reliably connected to the grounding terminal of the equipment motherboard, and the power feeding spring 12 is connected to the RF signal input terminal of the motherboard;

[0062] When installing the second antenna 2, the second radiator of the second antenna 2 needs to be arranged near the grounding spring 11 of the first antenna 1, with a close spacing of 10mm between them.

[0063] The grounding connection with the second radiator of the second antenna 2 is achieved through the broken line structure 13. The broken line structure 13 needs to be pre-designed into a specific shape to optimize the impedance matching of the second antenna 2 and the isolation from the first antenna 1.

[0064] Step 2: During the connection process of the first antenna 1 and the second antenna 2, the first antenna 1 receives and transmits multi-band signals through the feed spring 12, including N28, N3, N1, N41, N78, and N79.

[0065] The second antenna 2 is connected to the antenna RF connector of the 5G module 4 via a coaxial cable 9. It mainly covers the N1 frequency band and works with the first antenna 1 to extend the coverage of the N41, N78, and N79 frequency bands.

[0066] Based on the above technical solution, in step three, the feed spring 12 of the first antenna 1 is connected to the antenna RF connector of the 5G module 4 through the second coaxial cable 10, and the second antenna 2 is indirectly grounded through the parasitic ground spring 11. Furthermore, the grounding of the second antenna 2 is indirectly dependent on the grounding spring 11 of the first antenna 1 through the zigzag structure 13, which reduces the space occupied by independent grounding components and effectively suppresses co-channel interference.

[0067] During the specific debugging process, the mainstream 5G frequency bands, including N1, N3, N28, N41, N78, and N79, were switched through the equipment software to verify the signal strength and isolation index of each mainstream frequency band, ensuring that the signal strength is ≥-75dBm;

[0068] The broken line structure 13 is used to ensure an isolation of ≥15dB when operating at the same frequency, reducing interference at the same frequency. When signal abnormalities occur, the geometric parameters of the broken line structure 13 are adjusted to optimize impedance matching and make it match the impedance of the motherboard RF circuit. The geometric parameters include the number of bends, the length of the broken line, the angle of the broken line, and the line width spacing. This adjustment process needs to be debugged and calibrated during the mass production stage.

[0069] Step four involves potting the pre-installed antenna bracket inside the casing of the portable WiFi device after connection. Low dielectric loss resin is used for encapsulation to enhance mechanical strength and reduce environmental interference.

[0070] like Figure 5 and Figure 6As shown, in this embodiment, the return loss of the first antenna 1 and the second antenna 2 in the 5G frequency bands (N1, N3, N28, N41, N78, N79) is less than -6, which meets the requirements.

[0071] like Figure 7 As shown, the isolation in 5G co-channel (N1, N41, N78, N79) reaches more than 18dB, which meets the radio frequency specifications for inter-antenna isolation of 5G modules and can effectively suppress co-channel interference.

[0072] like Figure 8 and Figure 9 As shown, the efficiency of the first antenna 1 and the second antenna 2 is over 50%, which meets the high-efficiency design standard for antennas in portable WiFi devices.

[0073] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A composite 5G antenna for portable WiFi, characterized in that: It includes a first antenna (1) and a second antenna (2). Both the first antenna (1) and the second antenna (2) are mounted on the antenna bracket inside the housing of the portable WiFi device. The first antenna (1) includes a first radiator, a feed spring (12), two ground springs (11) and a second coaxial cable (10). The second antenna (2) includes a second radiator and a first coaxial cable (9). A motherboard (3) is installed on one side of the top of the portable WiFi device housing, and a 5G module (4) is installed on the other side of the top of the portable WiFi device housing. A grounding solder point (5) is provided on the inner side of the second antenna (2), and a power supply solder point (6) is provided on the inner side of the second antenna (2) on one side of the grounding solder point (5). The power supply solder point (6) is connected to the antenna interface (7) on the 5G module (4) through a coaxial cable (9). An antenna interface (8) is provided on the side of the 5G module (4) on one side of the antenna interface (7), and a coaxial cable (10) is connected to the antenna interface (8). The first antenna (1) is provided with a feeding spring (12) inside, and grounding springs (11) are provided on both sides of the feeding spring (12). The feeding spring (12) is connected to the antenna RF connector of the 5G module (4) through a 50-ohm impedance transmission line via a coaxial cable (10). The second antenna (2) uses the grounding spring (11) of the first antenna (1) as its own grounding reference, that is, the ground of the second antenna (2) is the grounding spring (11) of the first antenna (1), and the second radiator of the second antenna (2) is arranged adjacent to the grounding spring (11) of the first antenna (1) to form a parasitic coupling structure. The grounding position of the second antenna (2), that is, the connection area between the second radiator of the second antenna (2) and the grounding spring (11) of the first antenna (1), is provided with a broken line structure (13).

2. The composite 5G antenna for portable WiFi as described in claim 1, characterized in that: The first radiator of the first antenna (1) is used to receive 5G frequency band signals, specifically including the N28, N3, N1, N41, N78, and N79 frequency bands; The second radiator of the second antenna (2) is used to receive and transmit 5G band signals, specifically receiving 5G band signals in the N1 band, and transmitting and receiving 5G band signals in the N41, N78, and N79 bands.

3. The composite 5G antenna for portable WiFi as described in claim 1, characterized in that: The parasitic coupling structure refers to the grounding spring (11) of the first antenna (1) serving as the ground of the second antenna (2), which is equivalent to the second antenna (2) being parasitic on the first antenna (1). The adjacent spacing between the second radiator of the second antenna (2) and the grounding spring (11) of the first antenna (1) is 5-15mm.

4. A composite 5G antenna for portable WiFi as described in claim 3, characterized in that: Both antenna interface one (7) and antenna interface two (8) are located on the antenna RF connector of the 5G module (4).

5. A composite 5G antenna for portable WiFi as described in claim 1, characterized in that: The grounding spring (11) and the power supply spring (12) are both made of conductive materials, specifically copper, silver, or alloy. Both the grounding spring (11) and the power supply spring (12) are connected to the grounding terminal of the motherboard of the portable WiFi device.

6. A composite 5G antenna for portable WiFi as described in claim 1, characterized in that: The broken line structure (13) is used to adjust the impedance matching of the second antenna (2) and the isolation from the first antenna (1). The broken line structure (13) improves the low-frequency isolation by increasing the ground wire length and improves the bandwidth and efficiency by slot coupling.

7. An application method for a composite 5G antenna for portable WiFi as described in any one of claims 1-6, characterized in that: Includes the following steps: Step 1: Antenna assembly and layout; Step 2, circuit connection configuration; Step 3: Electrical connection and commissioning; Step four: Equipment integration and packaging.

8. The application method of a composite 5G antenna for portable WiFi according to claim 7, characterized in that: In step one, before assembling the antenna, it is necessary to confirm the installation position of the reserved antenna bracket inside the housing of the portable WiFi device, and ensure that the size of the antenna bracket matches the structure between the first antenna (1) and the second antenna (2) to meet the parasitic layout between the first antenna (1) and the second antenna (2). During the specific assembly process, the first antenna (1) and the second antenna (2) are installed on the antenna bracket inside the housing of the portable WiFi device. The positions of the first antenna (1) and the second antenna (2) need to be fixed. When installing the first antenna (1), it is necessary to ensure that its two grounding springs (11) are reliably connected to the grounding terminal of the equipment motherboard, and the power feeding spring (12) is connected to the RF signal input terminal of the motherboard; When installing the second antenna (2), the second radiator of the second antenna (2) needs to be arranged near the grounding spring (11) of the first antenna (1), with a spacing of 5-15mm between them; And the grounding connection with the second radiator of the second antenna (2) is achieved through the broken line structure (13); In step two, during the connection process of the first antenna (1) and the second antenna (2), the first antenna (1) receives and transmits multi-band signals through the feed spring (12), including N28, N3, N1, N41, N78, and N79. The second antenna (2) is connected to the antenna RF connector of the 5G module (4) via a coaxial cable (9), mainly covering the N1 band, and working with the first antenna (1) to extend the coverage of the N41, N78 and N79 bands.

9. The application method of a composite 5G antenna for portable WiFi according to claim 7, characterized in that: In step three, the feed spring (12) of the first antenna (1) is connected to the antenna RF connector of the 5G module (4) through the second coaxial cable (10). The second antenna (2) is indirectly grounded through the parasitic ground spring (11). Furthermore, the grounding of the second antenna (2) is indirectly dependent on the grounding spring (11) of the first antenna (1) through the broken line structure (13). During the specific debugging process, the mainstream 5G frequency bands, including N1, N3, N28, N41, N78, and N79, were switched through the equipment software to verify the signal strength and isolation index of each mainstream frequency band, ensuring that the signal strength is ≥-75dBm; And the broken line structure (13) is used to ensure that the isolation is ≥15dB when working at the same frequency. When a signal abnormality occurs, the geometric parameters of the broken line structure (13) are adjusted to optimize the impedance matching so that it matches the impedance of the motherboard RF circuit. This adjustment process needs to be completed and calibrated during the mass production stage. Step four involves potting the pre-installed antenna bracket inside the casing of the portable WiFi device after connection, using low dielectric loss resin for encapsulation.

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