A high-efficiency IFA antenna system and corresponding electronic equipment

Abstract

The present invention discloses a high-efficiency IFA antenna system and corresponding electronic equipment. The antenna system includes a matching network, an IFA antenna and a switch network. Among them, the two transmission lines in the IFA antenna are respectively connected to the matching network and the switch network, and dual resonance is achieved through the coordinated work of the matching network and the switch network, completing the work of the antenna system transmitting and receiving communication signals of each frequency band. The present invention utilizes the coordinated work of the matching network and the switch network to achieve coverage and switching of each target frequency band, and by changing the distribution connection mode and inductance value of the series inductance and branch inductance in the switch network, on the basis of ensuring the excellent S parameters of the antenna system, the power loss on the switches of each frequency band is reduced, so that the radiation efficiency and system efficiency of the antenna system are significantly improved.

Description

Technical Field

[0001] The present invention relates to a high-efficiency IFA antenna system and also relates to electronic equipment comprising the IFA antenna system, belonging to the technical field of wireless communications. Background Art

[0002] In wireless communication devices, the antenna system is an important component for transmitting and receiving communication signals. The IFA (Inverted-F Antenna) antenna is an inverted F-type antenna, which is obtained by adding a ground path to an inverted L-shaped monopole antenna. It is a typical built-in antenna and is widely used in existing wireless communication devices.

[0003] As wireless communication equipment is increasingly pursuing the development trend of thinness and large screen-to-body ratio, the space left for the antenna system is very limited, so it is necessary to further reduce the physical size of the antenna system to meet the requirements. At the same time, the miniaturized antenna system is also required to have multi-band and wide-band working characteristics. In the prior art, the methods for miniaturizing antenna systems usually include material loading, current loading, meandering, matching networks, coupled feeding and other technical solutions, and the methods for broadbanding antenna systems usually include widening the antenna width, multi-resonance, multi-mode, matching networks, coupled feeding and other technical solutions. On the other hand, since the addition of lumped elements and switching elements will also lead to increased antenna system losses and reduced efficiency, how to reduce losses and improve antenna system efficiency has become a problem that needs to be solved urgently.

[0004] In the Chinese invention patent with the authorization announcement number CN107394358B, an antenna structure and an electronic device are disclosed. The antenna structure includes: an IFA antenna assembly, the IFA antenna assembly is located near the first conductive frame segment formed by the two breaks on the conductive frame, and the feed point and the first grounding point of the IFA antenna assembly are respectively electrically connected to the first conductive frame segment; wherein the IFA antenna assembly is relatively close to the first break of the two breaks, and the feed point is closer to the first break relative to the first grounding point; the second grounding point is located on the side of the IFA antenna assembly away from the first break, and the second grounding point forms a parasitic branch toward the second break of the two breaks to couple to the first conductive frame segment. Through this technical solution, the full-band coverage of the antenna structure can be achieved when the internal space of the electronic device is insufficient. Summary of the invention

[0005] The primary technical problem to be solved by the present invention is to provide a high-efficiency IFA antenna system.

[0006] Another technical problem to be solved by the present invention is to provide an electronic device including the above-mentioned IFA antenna system.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] According to a first aspect of an embodiment of the present invention, a high-efficiency IFA antenna system is provided, comprising a matching network, an IFA antenna and a switch network; wherein the matching network and the switch network work together to achieve dual resonance; two transmission lines in the IFA antenna are respectively connected to the matching network and the switch network; the switch network comprises N frequency band branches, each frequency band branch being connected in parallel to each other, wherein N is a positive integer greater than 1.

[0009] Preferably, the IFA antenna includes a first dielectric substrate 1a, a second dielectric substrate 1b, a third dielectric substrate 1c, a fourth dielectric substrate 1d, a first metal floor 2, a first antenna radiation metal patch 3, a second antenna radiation metal patch 4, a third antenna radiation metal patch 5, a fourth antenna radiation metal patch 6, and a first transmission line 7 and a second transmission line 8; wherein the fourth dielectric substrate 1d is vertically connected to the first dielectric substrate 1a, the second dielectric substrate 1b, and the third dielectric substrate 1c, the first metal floor 2 is covered below the fourth dielectric substrate 1d, the first antenna radiation metal patch 3, the second antenna radiation metal patch 4, the third antenna radiation metal patch 5, and the fourth antenna radiation metal patch 6 are respectively covered on the outside of the first dielectric substrate 1a, the second dielectric substrate 1b, and the third dielectric substrate 1c; one end of the first transmission line 7 and the second transmission line 8 are respectively connected to the first metal floor 2 and the second antenna radiation metal patch 4, the other end of the first transmission line 7 is connected to the matching network, and the other end of the second transmission line 8 is connected to the switch network.

[0010] Preferably, the first metal floor 2 in the IFA antenna is etched on the lower surface of the fourth dielectric substrate 1d through the PCB process, and the first antenna radiation metal patch 3, the second antenna radiation metal patch 4, the third antenna radiation metal patch 5, and the fourth antenna radiation metal patch 6 are respectively etched on the outer surfaces of the first dielectric substrate 1a, the second dielectric substrate 1b, and the third dielectric substrate 1c through the PCB process.

[0011] Preferably, the first thickness of the first dielectric substrate 1a, the second dielectric substrate 1b, and the third dielectric substrate 1c is 2 mm, and the second thickness of the fourth dielectric substrate 1d is 0.8 mm; the width of the first metal floor 2 is slightly greater than that of the fourth dielectric substrate 1d.

[0012] Preferably, the first transmission line 7 and the second antenna radiation metal patch 4 are both fed by discrete feeding ports 9 .

[0013] Preferably, the switching network includes N frequency band branches and a first series inductor L0, and the N frequency band branches are respectively composed of a frequency band switch and a branch inductor connected in series; wherein, the branch inductor ends of the N frequency band branches are connected in parallel with each other and then connected to the first series inductor L0, the other end of the first series inductor L0 is connected to the second transmission line 8 in the IFA antenna, and the frequency band switch ends of the N frequency band branches are respectively connected to the ground potential end.

[0014] Preferably, the switch network includes N frequency band branches and N series inductors, and each of the N frequency band branches is respectively composed of a frequency band switch and a branch inductor connected in series; wherein, the branch inductor end of the first frequency band branch is connected to the first series inductor L0 and the second series inductor L1, the other end of the first series inductor L0 is connected to the second transmission line 8 in the IFA antenna, the second series inductor L1, the third series inductor L2 and the Nth series inductor Ln, a total of N-1 series inductors, are respectively connected between the branch inductor ends of the N frequency band branches, and the frequency band switch ends of the N frequency band branches are respectively connected to the ground potential end.

[0015] Preferably, the series inductance and branch inductance in the switch network are distributed or lumped inductances, and the frequency band switch is an SP4T or SPST switch.

[0016] According to a second aspect of an embodiment of the present invention, an electronic device is provided, comprising the above-mentioned high-efficiency IFA antenna system.

[0017] Compared with the prior art, the IFA antenna system provided by the present invention utilizes the coordinated work of the matching network and the switch network to achieve coverage and switching of each target frequency band, and by changing the distribution connection mode and inductance value of the series inductor and the branch inductor in the switch network, the power loss on the switches of each frequency band is reduced while ensuring the excellent S parameters of the antenna system, so that the radiation efficiency and system efficiency of the antenna system are significantly improved. Therefore, the present invention has the beneficial effects of ingenious and reasonable structural design, low production cost, small chip size, excellent system performance and system efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A structural block diagram of a high-efficiency IFA antenna system provided by the present invention;

[0019] Figure 2 It is a structural schematic diagram of an IFA antenna in the first embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of a dielectric structure of an IFA antenna in the first embodiment of the present invention;

[0021] Figure 4This is a schematic diagram of the metal structure of the IFA antenna in the first embodiment of the present invention;

[0022] Figure 5 This is a structural dimension diagram of an IFA antenna in the first embodiment of the present invention;

[0023] Figure 6 A feeding port and structural dimension diagram of an IFA antenna in the first embodiment of the present invention;

[0024] Figure 7 A circuit schematic diagram of a switch network in the first embodiment of the present invention;

[0025] Figure 8 A circuit schematic diagram of a switch network in a second embodiment of the present invention;

[0026] Fig. 9 The S11 parameter test result of the antenna system in the B28 frequency band in the first embodiment of the present invention;

[0027] Fig.10 The radiation efficiency and system efficiency test results of the antenna system in the B28 frequency band in the first embodiment of the present invention;

[0028] Fig.11 The S11 parameter test result of the antenna system in the B28 frequency band in the second embodiment of the present invention;

[0029] Fig.12 The radiation efficiency and system efficiency test results of the antenna system in the B28 frequency band in the second embodiment of the present invention;

[0030] Fig.13 This is an example diagram of an electronic device using the IFA antenna system provided by the present invention. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, a high-efficiency IFA antenna system provided by the present invention comprises at least a matching network, an IFA antenna and a switch network. The two transmission lines in the IFA antenna are respectively connected to the matching network and the switch network, and dual resonance is achieved through the coordinated work of the matching network and the switch network, so that the antenna system can transmit and receive communication signals of various frequency bands.

[0033] Among them, the matching network is composed of conventional adjustable LC elements, and its function is to adjust the impedance matching of the antenna system and achieve matching resonance together with the switching network.

[0034] In the first embodiment of the present invention, taking the mobile phone antenna in the wireless communication device as an example, Figure 2 As shown, the IFA antenna is composed of a first dielectric substrate 1a, a second dielectric substrate 1b, a third dielectric substrate 1c, a fourth dielectric substrate 1d, a first metal floor 2, a first antenna radiation metal patch 3, a second antenna radiation metal patch 4, a third antenna radiation metal patch 5, a fourth antenna radiation metal patch 6, a first transmission line 7, and a second transmission line 8. Among them, the fourth dielectric substrate 1d is vertically connected to the first dielectric substrate 1a, the second dielectric substrate 1b, and the third dielectric substrate 1c, and the first metal floor 2 is covered below the fourth dielectric substrate 1d. The first antenna radiation metal patch 3, the second antenna radiation metal patch 4, the third antenna radiation metal patch 5, and the fourth antenna radiation metal patch 6 are respectively covered on the outside of the first dielectric substrate 1a, the second dielectric substrate 1b, and the third dielectric substrate 1c. One end of the first transmission line 7 and the second transmission line 8 are respectively connected to the first metal floor 2 and the second antenna radiation metal patch 4, the other end of the first transmission line 7 is connected to the matching network, and the other end of the second transmission line 8 is connected to the switch network.

[0035] The first metal floor 2 is etched on the lower surface of the fourth dielectric substrate 1d through the PCB process, and the first antenna radiation metal patch 3, the second antenna radiation metal patch 4, the third antenna radiation metal patch 5, and the fourth antenna radiation metal patch 6 are respectively etched on the outer surfaces of the first dielectric substrate 1a, the second dielectric substrate 1b, and the third dielectric substrate 1c through the PCB process.

[0036] like Figure 3 As shown, the first dielectric substrate 1a, the second dielectric substrate 1b, the third dielectric substrate 1c, and the fourth dielectric substrate 1d are all made of FR-4 flame resistant material. In one embodiment of the present invention, the dielectric constant thereof is preferably 4.3. The first thickness of the first dielectric substrate 1a, the second dielectric substrate 1b, and the third dielectric substrate 1c is 2 mm, and the second thickness of the fourth dielectric substrate 1d is 0.8 mm.

[0037] like Figure 4 As shown, in one embodiment of the present invention, the thickness of the first antenna radiation metal patch 3, the second antenna radiation metal patch 4, the third antenna radiation metal patch 5, and the fourth antenna radiation metal patch 6 is 0.02 mm. The width of the first metal floor 2 is slightly larger than the fourth dielectric substrate 1d.

[0038] like Figure 5 As shown, in one embodiment of the present invention, the length of the first antenna radiation metal patch 3 and the fourth antenna radiation metal patch 6 is 142 mm and the height is 7 mm, and the total length of the second antenna radiation metal patch 4 and the third antenna radiation metal patch 5 is 84 mm.

[0039] like Figure 6 As shown, in one embodiment of the present invention, the first transmission line 7 and the second transmission line 8 are separated by a predetermined distance, the first transmission line 7 is 15 mm away from the short-circuit point, the second transmission line 8 is 8 mm away from the open-circuit point, and the total length of the antenna is 58.5 mm. The first transmission line 7 and the second antenna radiation metal patch 4 are both fed by the feeding port 9, and the feeding port 9 is fed in a discrete port manner.

[0040] In a high-efficiency IFA antenna system provided by the present invention, the switch network is composed of switch branches of each target frequency band connected in parallel. In the first embodiment of the present invention, the B28, B20, B5, and B8 frequency bands are taken as examples for analysis and description.

[0041] like Figure 7 As shown, the switch network is composed of a B28 frequency band branch, a B20 frequency band branch, a B5 frequency band branch, a B8 frequency band branch and a first series inductor L0. Among them, one end of the B28 frequency band branch, the B20 frequency band branch, the B5 frequency band branch and the B8 frequency band branch are connected in parallel to one end of the first series inductor L0, and the other end of the first series inductor L0 is connected to the second transmission line 8 in the IFA antenna. Each frequency band branch is composed of a frequency band switch and a branch inductor in series. Specifically, the B28 frequency band branch is composed of a first frequency band switch K28 and a first branch inductor L28 in series, the other end of the first branch inductor L28 is connected to the first series inductor L0, and the other end of the first frequency band switch K28 is connected to the ground potential end. The B20 frequency band branch is composed of the second frequency band switch K20 and the second branch inductor L20 connected in series, the other end of the second branch inductor L20 is connected to the first series inductor L0, and the other end of the second frequency band switch K20 is connected to the ground potential end. The B5 frequency band branch is composed of the third frequency band switch K5 and the third branch inductor L5 connected in series, the other end of the third branch inductor L5 is connected to the first series inductor L0, and the other end of the third frequency band switch K5 is connected to the ground potential end. The B8 frequency band branch is composed of the fourth frequency band switch K8 and the fourth branch inductor L8 connected in series, the other end of the fourth branch inductor L8 is connected to the first series inductor L0, and the other end of the fourth frequency band switch K8 is connected to the ground potential end.

[0042] The series inductor and the branch inductor can be distributed or lumped inductors, as well as other forms of inductors. The frequency band switch can be SP4T or SPST switch, as well as other forms of switches.

[0043] Combine the following Figure 7 , the working principle of a high-efficiency IFA antenna system provided by the present invention is described in detail.

[0044] The IFA antenna system provided by the embodiment of the present invention utilizes reconfigurable technology to achieve dual resonance through the coordinated work of the matching network and the switch network, and achieves coverage of the entire target frequency band through the switching of the frequency band switch. Figure 7 As shown, the technical solution adopted by the present invention is to reduce the branch inductance of each frequency band branch in series in the switch network and increase the series inductance between the switch network and the IFA antenna.

[0045] When each frequency band branch is turned on, the frequency band switch can be equivalent to a small resistor; when each frequency band branch is turned off, the frequency band switch can be equivalent to a large resistor Roff in parallel with a capacitor Coff. Therefore, when the frequency band branch is turned off, the load voltage V2 on the frequency band switch is calculated as follows:

[0046]

[0047] Among them, V1 is the loading voltage on the frequency band branch, that is, Figure 7 The voltage at the middle node A; V2 is the load voltage on the frequency band switch, that is, Figure 7 The voltage at the middle node B; Roff is the equivalent resistance when the band switch is off; Coff is the equivalent capacitance when the band switch is off; L is the branch inductance connected in series on the band branch.

[0048] When the band switch is off, the power loss P on its equivalent resistance Roff is calculated as follows:

[0049]

[0050] According to formula (1) and formula (2), when the series branch inductance L in the band branch decreases, the load voltage V2 on the band switch decreases accordingly, and the power loss P on the equivalent resistance Roff of the band switch also decreases accordingly, and the efficiency of the antenna system is improved.

[0051] In the first embodiment of the present invention, taking the B28 frequency band branch as an example, an inductor L0 is added between the IFA antenna and the switch network to reduce the inductance value of the branch inductor L28 connected in series on the B28 frequency band branch, thereby reducing the load voltage V2 on the frequency band switch K28 and reducing the power loss caused by the frequency band switch, thereby effectively improving the efficiency of the antenna system. The working principles of other frequency band branches are the same and will not be repeated.

[0052] In a second embodiment of the present invention, Figure 8As shown, a high-efficiency IFA antenna system provided by the present invention at least includes a matching network, an IFA antenna and a switch network. The matching network and the IFA antenna are the same as those in the first embodiment described above. On the basis of the first embodiment described above, the switch network further increases the series inductance between the branches of each frequency band, and minimizes the branch inductance value of the branches connected in series with each frequency band, so as to further reduce the power loss caused by the frequency band switch, thereby maximizing the efficiency of the antenna system.

[0053] Among them, Figure 8 As shown, the second series inductor L1 is connected in series between the B28 frequency band branch and the B20 frequency band branch, the third series inductor L2 is connected in series between the B20 frequency band branch and the B5 frequency band branch, and the fourth series inductor L3 is connected in series between the B5 frequency band branch and the B8 frequency band branch.

[0054] Other aspects of the second embodiment of the present invention, such as the matching network, IFA antenna, working principle, system performance, etc., are the same or similar to those of the first embodiment, and therefore will not be described in detail herein.

[0055] In order to verify the excellent performance of the IFA antenna system provided by the embodiment of the present invention, the inventors Figure 7 The technical solution provided by the first embodiment shown, and Figure 8 The technical solution provided by the second embodiment shown in the figure firstly performs two comparative simulation tests (antenna reflection coefficient S11, radiation efficiency and system efficiency) for the B28 frequency band. The existing technical solution compared with the two technical solutions is as follows: Figure 7 The system solution when no series inductor L0 is added to the IFA antenna system shown.

[0056] Fig. 9 The S11 parameter test results of the antenna system in the B28 frequency band in the technical solution provided in the first embodiment of the present invention; Fig.10 In the technical solution provided in the first embodiment of the present invention, the test results of the antenna system radiation efficiency and system efficiency in the B28 frequency band.

[0057] Fig.11 The S11 parameter test results of the antenna system in the B28 frequency band in the technical solution provided in the second embodiment of the present invention; Fig.12 In the technical solution provided for the second embodiment of the present invention, the test results of the antenna system radiation efficiency and system efficiency in the B28 frequency band.

[0058] from Fig. 9 and Fig.11It can be seen that within the bandwidth of 700MHz to 780MHz, the antenna system of the prior art solution resonates at f1 and f2. In the technical solution provided by the first embodiment and the technical solution provided by the second embodiment of the present invention, the series inductance and branch inductance in the matching network and the switch network are adjusted respectively, so that the antenna system also resonates at f1 and f2, and then a comparative test of radiation efficiency and system efficiency is performed.

[0059] from Fig.10 and Fig.12 It can be seen that within the bandwidth of 700MHz to 780MHz, the radiation efficiency of the existing technical solution reaches -5.83dB, and the system efficiency reaches -6.36dB; the radiation efficiency of the technical solution provided by the first embodiment of the present invention reaches -5.36dB, and the system efficiency reaches -5.91dB; the radiation efficiency of the technical solution provided by the second embodiment of the present invention reaches -5.13dB, and the system efficiency reaches -5.73dB. Compared with the existing technical solution, it can be seen that the radiation efficiency of the technical solution provided by the first embodiment of the present invention is improved by 0.47dB, and the system efficiency is improved by 0.45dB; the radiation efficiency of the technical solution provided by the second embodiment of the present invention is improved by 0.7dB, and the system efficiency is improved by 0.63dB.

[0060] Using the above-mentioned simulation test method, the inventors conducted two comparative simulation tests (antenna reflection coefficient S11, radiation efficiency and system efficiency) on the technical solution of the IFA antenna system provided by the present invention for the B20, B5 and B8 frequency bands respectively. After comparing the data with the existing technical solutions, it can be seen that the radiation efficiency of the technical solution provided by the first embodiment of the present invention can be improved by an average of 0.47dB to 0.79dB, and the system efficiency can be improved by an average of 0.45dB to 0.68dB; the radiation efficiency of the technical solution provided by the second embodiment of the present invention can be improved by an average of 0.7dB to 0.76dB, and the system efficiency can be improved by an average of 0.63dB to 0.68dB.

[0061] It should be noted that the application scope of the high-efficiency IFA antenna system provided by the present invention is not limited to the B28, B20, B5, and B8 frequency bands proposed in the embodiment, nor is it limited to the structural dimensions given in the embodiment, and is not limited to factors such as the structural form and parameters of the matching network and the switch network.

[0062] The high-efficiency IFA antenna system provided by the present invention can be used in electronic devices as an important component of communication components. The electronic devices mentioned here refer to computer devices that can be used in mobile environments and support multiple communication formats such as GSM, EDGE, TD_SCDMA, TDD_LTE, FDD_LTE, including mobile phones, laptops, tablet computers, car computers, etc. In addition, the technical solution provided by the present invention is also applicable to other occasions where radio frequency integrated circuits are applied, such as communication base stations, smart connected cars, etc.

[0063] like Fig.13 As shown, the electronic device includes at least a processor and a memory, and may further include a communication component, a sensor component, a power component, a multimedia component and an input / output interface according to actual needs. Among them, the memory, the communication component, the sensor component, the power component, the multimedia component and the input / output interface are all connected to the processor. The memory may be a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, etc., and the processor may be a central processing unit (CPU), a graphics processing unit (GPU), a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a digital signal processing (DSP) chip, etc. Other communication components, sensor components, power components, multimedia components, etc. may all be implemented using general components, which will not be specifically described here.

[0064] It can be seen from the specific description of the technical solution of the present invention in the above embodiments that the IFA antenna system provided by the present invention uses the coordinated work of the matching network and the switch network to achieve coverage and switching of each target frequency band, and by changing the distribution connection mode and inductance value of the series inductor and the branch inductor in the switch network, the power loss on the switches of each frequency band is reduced on the basis of ensuring the excellent S parameters of the antenna system, so that the radiation efficiency and system efficiency of the antenna system are significantly improved. Therefore, the high-efficiency IFA antenna system provided by the present invention has the beneficial effects of ingenious and reasonable structural design, low production cost, small chip size, excellent system performance and system efficiency.

[0065] The above is a detailed description of a high-efficiency IFA antenna system and corresponding electronic equipment provided by the present invention. For those skilled in the art, any obvious changes made to it without departing from the essence of the present invention will fall within the scope of protection of the patent right of the present invention.

Claims

1. A high-efficiency IFA antenna system, comprising a matching network, characterized in that Also included are the IFA antenna and switch network; wherein, The matching network and the switch network work together to achieve double resonance; The two transmission lines in the IFA antenna are connected to the matching network and the switch network respectively; The switch network includes N frequency band branches and a series inductor; or, the switch network includes N frequency band branches and N series inductors; by reducing the branch inductance of each frequency band branch in series in the switch network, the series inductance between the switch network and the IFA antenna is increased to improve the efficiency of the antenna system; wherein N is a positive integer greater than 1; The IFA antenna system realizes dual resonance through the coordinated work of the matching network and the switch network, and realizes coverage of the entire target frequency band through the switching of the frequency band switch in the switch network.

2. The IFA antenna system according to claim 1, characterized in that: The IFA antenna comprises a first dielectric substrate (1a), a second dielectric substrate (1b), a third dielectric substrate (1c), a fourth dielectric substrate (1d), a first metal floor (2), a first antenna radiation metal patch (3), a second antenna radiation metal patch (4), a third antenna radiation metal patch (5), a fourth antenna radiation metal patch (6), a first transmission line (7), and a second transmission line (8); wherein the fourth dielectric substrate (1d) is vertically connected to the first dielectric substrate (1a), the second dielectric substrate (1b), and the third dielectric substrate (1c); and the fourth dielectric substrate (1d) is vertically connected to the first dielectric substrate (1a), the second dielectric substrate (1b), and the third dielectric substrate (1c). A first metal floor (2) is covered at the bottom, and a first antenna radiation metal patch (3), a second antenna radiation metal patch (4), a third antenna radiation metal patch (5), and a fourth antenna radiation metal patch (6) are respectively covered on the outside of the first dielectric substrate (1a), the second dielectric substrate (1b), and the third dielectric substrate (1c); one end of the first transmission line (7) and the second transmission line (8) are respectively connected to the first metal floor (2) and the second antenna radiation metal patch (4), the other end of the first transmission line (7) is connected to the matching network, and the other end of the second transmission line (8) is connected to the switch network.

3. The IFA antenna system according to claim 2, wherein: The first metal floor (2) is etched on the lower surface of the fourth dielectric substrate (1d) through a PCB process, and the first antenna radiation metal patch (3), the second antenna radiation metal patch (4), the third antenna radiation metal patch (5), and the fourth antenna radiation metal patch (6) are respectively etched on the outer surfaces of the first dielectric substrate (1a), the second dielectric substrate (1b), and the third dielectric substrate (1c) through a PCB process.

4. The IFA antenna system according to claim 2, wherein: The first dielectric substrate (1a), the second dielectric substrate (1b), and the third dielectric substrate (1c) have a first thickness, and the fourth dielectric substrate (1d) has a second thickness; the width of the first metal floor (2) is slightly greater than that of the fourth dielectric substrate (1d).

5. The IFA antenna system according to claim 2, characterized in that: The first transmission line (7) and the second transmission line (8) are spaced apart by a predetermined distance; the first transmission line (7) and the second antenna radiation metal patch (4) are both fed by a discrete feeding port (9).

6. The IFA antenna system according to claim 1, wherein: The switch network comprises N frequency band branches and a first series inductor (L0), wherein the N frequency band branches are respectively composed of a frequency band switch and a branch inductor connected in series; wherein the branch inductor ends of the N frequency band branches are connected in parallel to each other and then connected to the first series inductor (L0), the other end of the first series inductor (L0) is connected to a second transmission line (8) in the IFA antenna, and the frequency band switch ends of the N frequency band branches are respectively connected to a ground potential end.

7. The IFA antenna system according to claim 1, wherein: The switch network comprises N frequency band branches and N series inductors, wherein each of the N frequency band branches is respectively composed of a frequency band switch and a branch inductor connected in series; wherein the branch inductor end of the first frequency band branch is connected to the first series inductor (L0) and the second series inductor (L1), the other end of the first series inductor (L0) is connected to the second transmission line (8) in the IFA antenna, the second series inductor (L1), the third series inductor (L2) and the Nth series inductor (Ln), a total of N-1 series inductors, are respectively connected between the branch inductor ends of the N frequency band branches, and the frequency band switch ends of the N frequency band branches are respectively connected to the ground potential end.

8. The IFA antenna system according to claim 6 or 7, characterized in that: The series inductor and the branch inductor in the switch network are distributed or lumped inductors, and the frequency band switch is an SP4T or SPST switch.

9. An electronic device, characterized in that The IFA antenna system comprises any one of claims 1 to 8.

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