PIFA antenna and intelligent terminal with same

Abstract

The invention provides a PIFA antenna and an intelligent terminal having the same. The PIFA antenna comprises a grounding plate; the radiation sheet is arranged opposite to the grounding plate; two ends of the short circuit sheet are respectively connected with the grounding plate and the radiation sheet; the feeder line comprises an inner conductor and an outer conductor penetrating through the inner conductor, the outer conductor is connected with the grounding plate, and the inner conductor is connected with the radiation sheet; wherein an L-shaped groove and a T-shaped groove are formed in the surface, deviating from the grounding plate, of the radiation sheet, the L-shaped groove comprises a first groove section and a second groove section which are perpendicular to each other, one end of the first groove section is connected with one end of the second groove section, the other end of the second groove section penetrates through the side edge of the radiation sheet, and the T-shaped groove comprises a third groove section and a fourth groove section which are perpendicular to each other. One end of the third groove section is connected with the middle of the fourth groove section, and the other end of the third groove section penetrates through the side edge of the radiation sheet. Through the technical scheme provided by the invention, the problem that a PIFA antenna serving as a terminal antenna in the prior art cannot adapt to the current multi-frequency requirement can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave antennas, and in particular to a PIFA antenna and an intelligent terminal having the same. Background Art

[0002] The PIFA antenna (Planar Inverted-Fantenna) has attracted much attention. It is evolved from a microstrip antenna with one end short-circuited. Since one end of the PIFA antenna is short-circuited, the antenna size can be greatly reduced, so it is widely used in terminal antennas.

[0003] In the related art, a PIFA antenna includes a radiation patch, a coaxial feed line, a short-circuit metal sheet, and a ground plate which are arranged in sequence from top to bottom.

[0004] However, with the rapid development of wireless networks, in order to meet the ever-changing Internet experience of users, wireless networks 2G, 3G, 4G and 5G have formed a situation where four generations of wireless networks live under the same roof. The PIFA antenna in the related technology as a terminal antenna cannot adapt to the current development needs of multi-frequency. Summary of the invention

[0005] The present invention provides a PIFA antenna and an intelligent terminal having the same, so as to solve the problem in the related art that the PIFA antenna as a terminal antenna cannot meet the current multi-frequency requirements.

[0006] According to one aspect of the present invention, a PIFA antenna is provided, which includes: a ground plate; a radiating plate, which is arranged opposite to the ground plate; a short-circuit plate, wherein both ends of the short-circuit plate are respectively connected to the ground plate and the radiating plate; a feed line, which includes an inner conductor and an outer conductor passing through the inner conductor, wherein the outer conductor is connected to the ground plate, and the inner conductor is connected to the radiating plate; wherein an L-shaped slot and a T-shaped slot are provided on a surface of the radiating plate facing away from the ground plate, wherein the L-shaped slot includes a first slot segment and a second slot segment which are perpendicular to each other, wherein one end of the first slot segment is connected to one end of the second slot segment, and the other end of the second slot segment passes through the side of the radiating plate, and wherein the T-shaped slot includes a third slot segment and a fourth slot segment which are perpendicular to each other, wherein one end of the third slot segment is connected to the middle of the fourth slot segment, and the other end of the third slot segment passes through the side of the radiating plate.

[0007] Furthermore, the radiation sheet is a rectangular structure, and the first slot segment, the second slot segment, the third slot segment and the fourth slot segment are all parallel to the side of the rectangular structure.

[0008] Furthermore, the radiation plate has a first long side and a second long side that are arranged opposite to each other, and the radiation plate also has a first short side and a second short side that are arranged opposite to each other, the first slot segment and the third slot segment are both parallel to the first long side, and the second slot segment and the fourth slot segment are both parallel to the first short side.

[0009] Further, the end of the second slot segment facing away from the first slot segment passes through the first long side, and the end of the third slot segment facing away from the fourth slot segment passes through the first short side.

[0010] Furthermore, the L-shaped slots and the T-shaped slots are arranged at intervals in the length direction of the radiation sheet, and the first slot section is located on a side of the second slot section that is away from the T-shaped slots.

[0011] Further, the length of the first slot segment is between 31 mm and 33 mm, and the length of the second slot segment is between 12.5 mm and 13.5 mm; and / or the length of the third slot segment is between 10.5 mm and 11.5 mm, and the length of the fourth slot segment is between 8.5 mm and 9.5 mm;

[0012] Furthermore, the groove width of the first groove segment, the groove width of the second groove segment, the groove width of the third groove segment and the groove width of the fourth groove segment are equal; and / or, the groove width of the first groove segment, the groove width of the second groove segment, the groove width of the third groove segment and the groove width of the fourth groove segment are all between 1.9 mm and 2.1 mm.

[0013] Furthermore, the shortest distance between the first slot segment and the side of the radiation plate is between 12 mm and 13 mm; the shortest distance between the fourth slot segment and the side of the radiation plate is between 2.9 mm and 3.1 mm; and the shortest distance between the L-shaped slot and the T-shaped slot is between 2.4 mm and 2.6 mm.

[0014] Furthermore, the connection position between the inner conductor and the radiation plate is located in the area surrounded by the side of the radiation plate, the first slot section and the second slot section.

[0015] Furthermore, the short-circuit plate is connected to the short side of the radiation plate.

[0016] Furthermore, the distance between the radiation plate and the ground plate is between 7.5 mm and 8.5 mm.

[0017] According to another aspect of the present invention, a smart terminal is provided. The smart terminal includes the PIFA antenna provided above.

[0018] The technical solution of the present invention is applied, and the PIFA antenna includes a ground plate, a radiating plate, a short-circuit plate and a feeder. The radiating plate is the main radiating part of the PIFA antenna. The radiating plate is indirectly connected to the ground plate through the short-circuit plate, so as to form a short circuit between the ground plate and the radiating plate by using the short-circuit plate, reduce the overall size of the PIFA antenna and control the current path, the inner conductor transmits the signal to the radiating plate, and the outer conductor is connected to the ground plate and sleeved on the inner conductor, so as to use the outer conductor to shield the inner conductor and improve the accuracy of the signal transmitted by the inner conductor. L-shaped grooves and T-shaped grooves are arranged on the surface of the radiating plate away from the ground plate, which can change the current distribution and current path on the surface of the radiating plate, wherein the setting of the L-shaped groove can form two relatively independent current loops on the surface of the radiating plate, forming two different resonance modes, and the T-shaped groove can resonate with the L-shaped groove to produce a third resonance mode, realize the resonance of three frequency bands, and enable the PIFA antenna as a terminal antenna to adapt to the current multi-frequency requirements. In addition, L-shaped grooves and T-shaped grooves are arranged on the surface of the radiating plate away from the ground plate, which is simple, practical and easy to process, and can reduce the size of the PIFA antenna. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic diagram of the structure of a PIFA antenna provided in an embodiment of the present invention is shown;

[0021] Figure 2 A top view of a PIFA antenna provided according to an embodiment of the present invention is shown;

[0022] Figure 3 shows a cross-sectional view of a PIFA antenna provided according to an embodiment of the present invention;

[0023] Figure 4 A schematic diagram showing the echo reflection and isolation effect of a PIFA antenna provided in an embodiment of the present invention is shown;

[0024] Figure 5 The GSM900MHz antenna radiation pattern of the PIFA antenna provided according to an embodiment of the present invention is shown;

[0025] Figure 6 The LTE 1.8 GHz antenna radiation pattern of the PIFA antenna provided in an embodiment of the present invention is shown;

[0026] Figure 7 The LTE 1.8 GHz antenna radiation pattern of the PIFA antenna provided according to an embodiment of the present invention is shown.

[0027] The above drawings include the following reference numerals:

[0028] 10. Ground plate;

[0029] 20, radiation piece; 21, L-shaped slot; 211, first slot section; 212, second slot section; 22, T-shaped slot; 221, third slot section; 222, fourth slot section; 23, first long side; 24, second long side; 25, first short side; 26, second short side;

[0030] 30. short-circuit plate; 40. feed line; 50. dielectric layer;

[0031] L1, length of the first slot segment; L2, length of the second slot segment; L3, length of the third slot segment; L4, length of the fourth slot segment; L5, shortest distance between the first slot segment and the side of the radiation piece; L6, shortest distance between the fourth slot segment and the side of the radiation piece; L7, shortest distance between the L-shaped slot and the T-shaped slot;

[0032] D1, the slot width of the first slot section; D2, the slot width of the second slot section; D3, the slot width of the third slot section; D4, the slot width of the fourth slot section;

[0033] H. Radiator and ground plane. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] like Figures 1 to 7As shown, an embodiment of the present invention provides a PIFA antenna, which includes a ground plate 10, a radiating plate 20, a short-circuit plate 30 and a feed line 40. The radiating plate 20 is arranged opposite to the ground plate 10, and two ends of the short-circuit plate 30 are respectively connected to the ground plate 10 and the radiating plate 20. The feed line 40 includes an inner conductor and an outer conductor passing through the inner conductor, the outer conductor is connected to the ground plate 10, and the inner conductor is connected to the radiating plate 20. The surface of the radiating plate 20 facing away from the ground plate 10 is provided with an L-shaped slot 21 and a T-shaped slot 22. The L-shaped slot 21 includes a first slot section 211 and a second slot section 212 which are perpendicular to each other, one end of the first slot section 211 is connected to one end of the second slot section 212, and the other end of the second slot section 212 passes through the side of the radiating plate 20. The T-shaped slot 22 includes a third slot section 221 and a fourth slot section 222 which are perpendicular to each other, one end of the third slot section 221 is connected to the middle of the fourth slot section 222, and the other end of the third slot section 221 passes through the side of the radiating plate 20.

[0036] The PIFA antenna provided in this embodiment is applied, and the PIFA antenna includes a ground plate 10, a radiating plate 20, a short-circuit plate 30 and a feed line 40. The radiating plate 20 serves as the main radiating part of the PIFA antenna. The radiating plate 20 is indirectly connected to the ground plate 10 through the short-circuit plate 30, so that the short-circuit plate 30 is used to form a short circuit between the ground plate 10 and the radiating plate 20, thereby reducing the overall size of the PIFA antenna and controlling the current path. The inner conductor transmits the signal to the radiating plate 20, and the outer conductor is connected to the ground plate 10 and is sleeved on the inner conductor, so that the outer conductor can shield the inner conductor and improve the accuracy of the signal transmitted by the inner conductor. The L-shaped slot 21 and the T-shaped slot 22 are arranged on the surface of the radiation piece 20 away from the ground plate 10, which can change the current distribution and current path on the surface of the radiation piece 20. The L-shaped slot 21 can form two relatively independent current loops on the surface of the radiation piece 20, forming two different resonance modes. The T-shaped slot 22 can resonate with the L-shaped slot 21 to produce a third resonance mode, realize the resonance of three frequency bands, and enable the PIFA antenna as a terminal antenna to adapt to the current multi-frequency requirements. In addition, the L-shaped slot 21 and the T-shaped slot 22 are arranged on the surface of the radiation piece 20 away from the ground plate 10, which is simple, practical and easy to process, and can reduce the size of the PIFA antenna.

[0037] like Figure 1 As shown, the radiation plate 20 is a rectangular structure, and the first slot section 211, the second slot section 212, the third slot section 221 and the fourth slot section 222 are all parallel to the side of the rectangular structure. This not only simplifies the design and manufacture of the PIFA antenna, but also improves the frequency tuning capability, size optimization, isolation between frequency bands and overall communication performance of the PIFA antenna.

[0038] Specifically, the radiation plate 20 is a rectangular structure, so that the radiation plate 20 has a regular shape, which is convenient for parameter setting and theoretical analysis during design, and the first slot segment 211, the second slot segment 212, the third slot segment 221 and the fourth slot segment 222 follow the symmetry and regularity of the radiation plate 20, which can effectively control the distribution and path of the current, and facilitate the understanding and control of the current path and the radiation characteristics of the electromagnetic wave, simplifying the PIFA antenna design and optimization process. In addition, it also helps to control the impedance characteristics of the antenna, thereby achieving a relatively stable bandwidth in each frequency band, which is crucial to ensuring the communication quality and efficiency of the antenna in different frequency bands.

[0039] By slotting the surface of the radiation sheet 20 , current can flow along both sides of the slot to form an independent current loop, which helps to separate the resonances of different frequency bands, thereby improving the isolation between the frequency bands.

[0040] like Figure 2 As shown, the radiation plate 20 has a first long side 23 and a second long side 24 that are relatively set, and the radiation plate 20 also has a first short side 25 and a second short side 26 that are relatively set, the first slot section 211 and the third slot section 221 are both parallel to the first long side 23, and the second slot section 212 and the fourth slot section 222 are both parallel to the first short side 25, which helps to integrate the antenna with the circuit board and reduce errors and costs in the manufacturing process.

[0041] like Figure 2 As shown, the end of the second slot segment 212 facing away from the first slot segment 211 passes through the first long side 23, and the end of the third slot segment 221 facing away from the fourth slot segment 222 passes through the first short side 25, so that the antenna structure has good manufacturability and is easy to produce using a standard printed circuit board (PCB) manufacturing process.

[0042] like Figure 2 As shown, the L-shaped slots 21 and the T-shaped slots 22 are arranged at intervals in the length direction of the radiation plate 20 , and the first slot section 211 is located on a side of the second slot section 212 away from the T-shaped slot 22 .

[0043] like Figure 2 As shown, the length L1 of the first slot section 211 is between 31 mm and 33 mm, and the length L2 of the second slot section 212 is between 12.5 mm and 13.5 mm, so as to realize GSM900M / LTE1.8G dual-band operation.

[0044] The length L1 of the first slot segment 211 can be 31 mm, 32 mm, and 33 mm, and the length L2 of the second slot segment 212 can be 12.5 mm, 13 mm, and 13.5 mm. In this embodiment, the length L1 of the first slot segment 211 is 32 mm, and the length L2 of the second slot segment 212 is 13 mm.

[0045] like Figure 2 As shown, the length L3 of the third slot segment 221 is between 10.5 mm and 11.5 mm, and the length L4 of the fourth slot segment 222 is between 8.5 mm and 9.5 mm, so as to be able to resonate the 5G intermediate frequency NR3.5G band to meet the application requirements of today's 5G networks.

[0046] The length L3 of the third slot segment 221 can be 10.5 mm, 11 mm and 11.5 mm, and the length L4 of the fourth slot segment 222 can be 8.5 mm, 9 mm and 9.5 mm. In this embodiment, the length L3 of the third slot segment 221 is 11 mm, and the length L4 of the fourth slot segment 222 is 9 mm.

[0047] like Figure 2 As shown, the slot width D1 of the first slot segment 211 , the slot width D2 of the second slot segment 212 , the slot width D3 of the third slot segment 221 , and the slot width D4 of the fourth slot segment 222 are equal, which is convenient for parameter setting and theoretical analysis during design.

[0048] like Figure 2 As shown, the groove width D1 of the first groove segment 211 , the groove width D2 of the second groove segment 212 , the groove width D3 of the third groove segment 221 , and the groove width D4 of the fourth groove segment 222 are all between 1.9 mm and 2.1 mm.

[0049] Among them, the groove width D1 of the first groove segment 211, the groove width D2 of the second groove segment 212, the groove width D3 of the third groove segment 221 and the groove width D4 of the fourth groove segment 222 can all be 1.9 mm, 2 mm and 2.1 mm. In this embodiment, the groove width D1 of the first groove segment 211, the groove width D2 of the second groove segment 212, the groove width D3 of the third groove segment 221 and the groove width D4 of the fourth groove segment 222 are all 2 mm.

[0050] like Figure 2 As shown, the shortest distance L5 between the first slot section 211 and the side of the radiation piece 20 is between 12 mm and 13 mm. The shortest distance L5 between the first slot section 211 and the side of the radiation piece 20 can be 12 mm, 12.5 mm, and 13 mm. In this embodiment, the shortest distance L5 between the first slot section 211 and the side of the radiation piece 20 is 12.5 mm.

[0051] like Figure 2 As shown, the shortest distance L6 between the fourth slot section 222 and the side of the radiation piece 20 is between 2.9 mm and 3.1 mm. The shortest distance L6 between the fourth slot section 222 and the side of the radiation piece 20 can be 2.9 mm, 3 mm, and 3.1 mm. In this embodiment, the shortest distance L6 between the fourth slot section 222 and the side of the radiation piece 20 is 3 mm.

[0052] like Figure 2 As shown, the shortest distance L7 between the L-shaped slot 21 and the T-shaped slot 22 is between 2.4 mm and 2.6 mm, which helps to separate the resonances of different frequency bands, thereby improving the isolation between the frequency bands.

[0053] The shortest distance L7 between the L-shaped slot 21 and the T-shaped slot 22 may be 2.4 mm, 2.5 mm, or 2.6 mm. In the present embodiment, the shortest distance L7 between the L-shaped slot 21 and the T-shaped slot 22 is 2.5 mm.

[0054] like Figure 2 As shown, the connection position between the inner conductor and the radiation plate 20 is located in the area surrounded by the side of the radiation plate 20, the first slot section 211 and the second slot section 212 to ensure good impedance matching and radiation efficiency.

[0055] like Figure 2 As shown, the short-circuit plate 30 is connected to the short side of the radiation plate 20. In the PIFA antenna, the effective electrical length of the antenna is a key factor in determining the resonant frequency. By connecting the short-circuit plate 30 to the short side of the radiation plate 20, the electrical length of the antenna can be artificially shortened, so that the antenna can still resonate when the physical size is much smaller than the wavelength, thereby realizing the miniaturization of the antenna, which is particularly important for the compact design of mobile communication devices. In addition, the connection between the short-circuit plate 30 and the radiation plate 20 changes the current path on the radiation plate 20. When the current reaches the short-circuit plate 30, it is forced to fold back to form a compact current loop, which helps to achieve effective resonance at a lower frequency. At the same time, this design can suppress unnecessary high-frequency modes and help improve the performance of the antenna in a specified frequency band. The connection between the short-circuit plate 30 and the short side of the radiation plate 20 usually does not destroy the overall structural stability of the radiation plate 20. Compared with the connection with the long side of the radiation plate 20, the radiation plate 20 under this design is less susceptible to mechanical stress in space-constrained devices.

[0056] like Figure 1 As shown, the distance H between the radiation plate 20 and the ground plate 10 is between 7.5 mm and 8.5 mm.

[0057] The distance H between the radiation sheet 20 and the grounding plate 10 may be 7.5 mm, 8 mm, or 8.5 mm. In the present embodiment, the distance H between the radiation sheet 20 and the grounding plate 10 is 8 mm.

[0058] In this embodiment, an insulating space is provided between the outer wall of the inner conductor and the inner wall of the outer conductor, thereby improving the safety of the feeder 40. Specifically, the feeder 40 further includes an insulating layer, which is disposed in the insulating space. Specifically, the insulating layer may be made of materials such as FR4 or polytetrafluoroethylene (PTFE).

[0059] like Figure 3 As shown, the PIFA antenna further includes a dielectric layer 50, which is sandwiched between the radiation plate 20 and the ground plane 10, and the feed line 40 passes through the dielectric layer 50. In this embodiment, the dielectric layer 50 is made of air to improve the efficiency of the PIFA antenna.

[0060] In this embodiment, HFSS15.0 software is used to model and simulate the PIFA antenna, wherein the sweep frequency range is set between 0.7 GHz and 3.8 GHz, and the sweep frequency step is set to 0.01 GHz. The antenna dimensions that meet the design requirements are obtained through simulation design as follows: the length of the ground plate 10 is 120 mm, the width of the ground plate 10 is 60 mm, the spacing H between the radiation plate 20 and the ground plate 10 is 8 mm, the length of the first long side 23 and the length of the second long side 24 are both 60 mm, the length of the first short side 25 and the second short side 26 are both 18 mm, the width of the short-circuit plate 30 is 5 mm, the length L1 of the first slot section 211 is 32 mm, the length L2 of the second slot section 212 is 1 3mm, the length L3 of the third slot segment 221 is 11mm, the length L4 of the fourth slot segment 222 is 9mm, the shortest distance L5 between the first slot segment 211 and the side of the radiation plate 20 is 12.5mm, the shortest distance L6 between the fourth slot segment 222 and the side of the radiation plate 20 is 3mm, the shortest distance L7 between the L-shaped slot 21 and the T-shaped slot 22 is 2.5mm, the spacing H between the radiation plate 20 and the grounding plate 10 is 8mm, the distance between the connection position of the inner conductor and the radiation plate 20 and the first long side 23 is 42.5mm, the distance between the connection position of the inner conductor and the radiation plate 20 and the second short side 26 is 7mm, the diameter of the inner conductor is 0.25mm, and the diameter of the outer conductor is 0.59mm.

[0061] Through simulation analysis, the frequency bands in which the antenna's return loss is less than -10dB are 880MHz-960MHz, 1.76GHz-1.88GHz and 3.44GHz-3.57GHz, which completely cover the three frequency bands of GSM900MHz, LTE1.8GHz and LTE1.8GHz, meeting the bandwidth requirements of tri-band terminal antennas. The maximum gain of the antenna reaches 1.76dB in the GSM900MHz band, 1.45dB in the 1.8GHz band, and 2.48dB in the NR3.5GHz band, with good directional gain.

[0062] The PIFA antenna provided in this embodiment is applied, and an L-shaped slot 21 and a T-shaped slot 22 are set on the surface of the radiation plate 20 away from the ground plate 10. The L-shaped slot 21 divides the radiation plate 20 into two parts responsible for low-frequency resonance (such as GSM900M) and supporting high-frequency resonance (such as LTE1.8G). The T-shaped slot 22 can resonate with the L-shaped slot 21 to produce a third resonance mode, so that only one feeding point is used for feeding, and GSM900 / LTE1.8G / NR3.5G triple-frequency resonance can be achieved. It can be applied to the field of wireless network communications, has practical application value, and has the characteristics of simple design, small size, and easy adjustment of operating frequency, which greatly shortens the design cycle.

[0063] An embodiment of the present invention provides a smart terminal, and the smart terminal includes the PIFA antenna provided above. The smart terminal provided by this embodiment can also set an L-shaped slot 21 and a T-shaped slot 22 on the surface of the radiation plate 20 away from the ground plate 10, which can change the current distribution and current path on the surface of the radiation plate 20, wherein the setting of the L-shaped slot 21 can form two relatively independent current loops on the surface of the radiation plate 20, forming two different resonance modes, and the T-shaped slot 22 can resonate with the L-shaped slot 21 to produce a third resonance mode, realize resonance in three frequency bands, and enable the PIFA antenna as a terminal antenna to adapt to the current multi-frequency requirements. In addition, setting the L-shaped slot 21 and the T-shaped slot 22 on the surface of the radiation plate 20 away from the ground plate 10 is simple, practical and easy to process, and can reduce the size of the PIFA antenna.

[0064] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0065] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0066] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0067] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0068] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A PIFA antenna, characterized in that: The PIFA antenna comprises: A ground plate (10); A radiation plate (20) arranged opposite to the ground plate (10); A short-circuit plate (30), two ends of which are respectively connected to the ground plate (10) and the radiation plate (20); A feed line (40) comprising an inner conductor and an outer conductor passing through the inner conductor, wherein the outer conductor is connected to the ground plate (10), and the inner conductor is connected to the radiation plate (20); The surface of the radiation plate (20) facing away from the grounding plate (10) is provided with an L-shaped groove (21) and a T-shaped groove (22); the L-shaped groove (21) comprises a first groove section (211) and a second groove section (212) which are perpendicular to each other; one end of the first groove section (211) is connected to one end of the second groove section (212); the other end of the second groove section (212) passes through the side of the radiation plate (20); the T-shaped groove (22) comprises a third groove section (221) and a fourth groove section (222) which are perpendicular to each other; one end of the third groove section (221) is connected to the middle of the fourth groove section (222); the other end of the third groove section (221) passes through the side of the radiation plate (20).

2. The PIFA antenna according to claim 1, characterized in that: The radiation sheet (20) is a rectangular structure, and the first slot section (211), the second slot section (212), the third slot section (221) and the fourth slot section (222) are all parallel to the side edges of the rectangular structure.

3. The PIFA antenna according to claim 2, characterized in that: The radiation sheet (20) has a first long side (23) and a second long side (24) arranged opposite to each other, and the radiation sheet (20) also has a first short side (25) and a second short side (26) arranged opposite to each other, the first slot section (211) and the third slot section (221) are both parallel to the first long side (23), and the second slot section (212) and the fourth slot section (222) are both parallel to the first short side (25).

4. The PIFA antenna according to claim 3, characterized in that: The end of the second slot segment (212) facing away from the first slot segment (211) passes through the first long side (23), and the end of the third slot segment (221) facing away from the fourth slot segment (222) passes through the first short side (25).

5. The PIFA antenna according to claim 1, characterized in that: The L-shaped slot (21) and the T-shaped slot (22) are arranged at intervals in the length direction of the radiation plate (20), and the first slot section (211) is located on a side of the second slot section (212) away from the T-shaped slot (22).

6. The PIFA antenna according to claim 1, characterized in that: The length of the first groove section (211) is between 31 mm and 33 mm, and the length of the second groove section (212) is between 12.5 mm and 13.5 mm; and / or, The length of the third groove section (221) is between 10.5 mm and 11.5 mm, and the length of the fourth groove section (222) is between 8.5 mm and 9.5 mm.

7. The PIFA antenna according to claim 1, characterized in that: The groove width of the first groove section (211), the groove width of the second groove section (212), the groove width of the third groove section (221) and the groove width of the fourth groove section (222) are equal; and / or, The groove width of the first groove section (211), the groove width of the second groove section (212), the groove width of the third groove section (221) and the groove width of the fourth groove section (222) are all between 1.9 mm and 2.1 mm.

8. The PIFA antenna according to claim 1, characterized in that: The shortest distance between the first slot section (211) and the side edge of the radiation sheet (20) is between 12 mm and 13 mm; The shortest distance between the fourth slot section (222) and the side edge of the radiation sheet (20) is between 2.9 mm and 3.1 mm; The shortest distance between the L-shaped groove (21) and the T-shaped groove (22) is between 2.4 mm and 2.6 mm.

9. The PIFA antenna according to claim 1, characterized in that: The connection position between the inner conductor and the radiation plate (20) is located within a region surrounded by a side edge of the radiation plate (20), the first slot section (211) and the second slot section (212).

10. The PIFA antenna according to claim 1, characterized in that: The short-circuit plate (30) is connected to the short side of the radiation plate (20).

11. The PIFA antenna according to claim 1, characterized in that: The distance between the radiation plate (20) and the ground plate (10) is between 7.5 mm and 8.5 mm.

12. An intelligent terminal, characterized in that: The smart terminal comprises the PIFA antenna according to any one of claims 1 to 11.

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