Circularly polarized antenna and intelligent terminal for satellite communication of metal frame intelligent terminal

Abstract

The application discloses a circularly polarized antenna and a smart terminal for satellite communication of a metal frame smart terminal, and relates to the technical field of antennas. The circularly polarized antenna comprises a metal frame and a dielectric substrate arranged in the metal frame. Metal ground plates are arranged on both sides of the dielectric substrate, and the metal ground plates on both sides of the dielectric substrate are electrically connected through metallized through holes. A gap is arranged on the top of the metal frame, and the gap separates the metal frame. One end of the dielectric substrate close to the gap is not covered by the metal ground plate and forms a hollow opening. The metallized through holes surround the one end of the dielectric substrate close to the gap and combine with the hollow opening to form a magnetic dipole. The two metal ground plates at the magnetic dipole are connected to two separated connection ends in the metal frame through two parallel feed lines. A feed port is arranged on one side of the cavity close to the feed line. The antenna is easy to process and has low cost based on the specific design structure. The antenna has the advantages of a metal frame, a single-layer structure, an end-fire circularly polarized beam and the like, and has excellent practical application effects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless communication devices, and in particular to a circularly polarized antenna for satellite communication of a metal-frame smart terminal and a smart terminal. BACKGROUND

[0002] With the rapid development of smart communication technology, satellite communication in small smart terminals (such as mobile phones, satellite phones, etc.) has become an important function that needs to be developed, which has effectively expanded the coverage of communication services. This function can enable users in remote mountainous areas and at sea and other areas without cellular network coverage to still communicate seamlessly with the outside world. In satellite communication services, circularly polarized (CP) antennas are particularly special because circularly polarized antennas are not sensitive to the polarization mode of signal transmission and reception, so circular polarization is often used as the polarization mode of signals in satellite communication. In addition, the distance between the satellite and the terminal is far, which inevitably leads to a large amount of signal attenuation, so it is particularly important to align the transmission beam direction of the mobile terminal with the reception beam direction of the satellite in actual application. In order to achieve these functions, the antenna must have the characteristics of beam directional radiation and circular polarization.

[0003] Nowadays, smart terminal antennas are usually designed based on metal frames, because metal frames can bring users a better experience and increase the aesthetics of smart terminals. However, metal frames also bring some problems that cannot be ignored, the most important of which is that the existence of metal frames will reflect or couple with the electromagnetic waves radiated by the antennas on the mainboard of the terminal, which greatly deteriorates the radiation performance of the entire terminal antenna. Therefore, metal frames and directional radiation cannot be considered simultaneously, in other words, the directional circularly polarized beam cannot directly pass through the metal frame and maintain the original directional radiation characteristics. In recent years, several directional circularly polarized antennas for smart terminals have been reported, which can achieve end-fire circular polarization by coupling feed to loop antennas, differential feed circularly polarized antennas based on narrow cross-dipoles, and reconfigurable directional circularly polarized antennas by combining folding smart terminals, but these antennas cannot be applied to metal frames. There are also some dual-frequency circularly polarized microstrip antennas that can be used in smart terminals, and the circularly polarized radiation direction of this type of antenna is directed to the normal direction of the plane of the smart terminal, so it is not suitable for mobile terminal satellite communication with end-fire circular polarization characteristics.

[0004] In order to realize end-fire circular polarization in a smart terminal with extremely limited space, a lower profile end-fire circular polarization antenna is needed, in which a complementary dipole antenna is widely used. A magnetic dipole is formed by the establishment of a metal cavity, and another electric dipole is parallel to the cavity plane. A double-wire parallel line corresponding to the amplitude and phase difference between the magnetic dipole and the electric dipole is introduced, so as to realize planar end-fire circular polarization. However, the antenna size in the current technology is too large, and the ground clearance is 25.6mm. Therefore, in order to further reduce the size, the double-wire parallel line is bent, so as to realize end-fire circular polarization in a limited space. However, this type of complementary dipole antenna cannot be applied to terminals with metal frames, because the metal frame limits the deterioration of the directional radiation characteristics and circular polarization characteristics of the antenna.

[0005] Therefore, the complementary dipole antenna for satellite communication in the prior art method has the problem of being unable to be applied to a terminal with a metal frame. SUMMARY

[0006] Embodiments of the present application provide a circular polarization antenna for satellite communication of a smart terminal with a metal frame and a smart terminal, aiming to solve the problem that the complementary dipole antenna for satellite communication in the prior art method cannot be applied to a terminal with a metal frame.

[0007] In a first aspect, embodiments of the present application provide a circular polarization antenna for satellite communication of a smart terminal with a metal frame, which comprises a metal frame and a dielectric substrate arranged in the metal frame.

[0008] Both sides of the dielectric substrate are provided with metal ground plates, and the metal ground plates on both sides of the dielectric substrate are electrically connected through metallized vias. The top of the metal frame is provided with a gap, and the gap separates the metal frame.

[0009] One end of the dielectric substrate close to the gap is not covered with a metal ground plate and forms a hollow opening. The metallized vias form a semi-enclosed cavity around one end of the dielectric substrate close to the gap, and the cavity and the hollow opening form a magnetic dipole. The two metal ground plates at the magnetic dipole are connected to the connection ends on both sides of the gap in the metal frame through two parallel serpentine-shaped feed lines. The metal frame is further provided with a long strip-shaped through slot parallel to the dielectric substrate. The long strip-shaped through slot and the gap are perpendicular to each other. A coaxial feed terminal is arranged at a feed port of the dielectric substrate and connected to the two metal ground plates, and the feed port is arranged in the cavity close to one side of the feed line.

[0010] The circularly polarized antenna for satellite communication of the metal frame smart terminal, wherein the diameter of the metalized via hole is 0.5-3 mm, and the distance between the edges of adjacent metalized via holes is 1 / 3-1 / 2 of the diameter of the metalized via hole.

[0011] The circularly polarized antenna for satellite communication of the metal frame smart terminal, wherein the metalized via hole is arranged in a rectangular frame shape and forms a cavity of a rectangular structure together with the hollow opening.

[0012] The circularly polarized antenna for satellite communication of the metal frame smart terminal, wherein the length of the cavity of the rectangular structure is 5 / 7-3 / 4 of the width of the metal frame, and the width of the cavity is 2 / 7-1 / 3 of the length of the cavity.

[0013] The circularly polarized antenna for satellite communication of the metal frame smart terminal, wherein the distance between the feed port and the cavity away from one side of the feed line is 2 / 3-5 / 7 of the width of the cavity.

[0014] The circularly polarized antenna for satellite communication of the metal frame smart terminal, wherein the bending part of the feed line is chamfered.

[0015] The circularly polarized antenna for satellite communication of the metal frame smart terminal, wherein the height of the metal frame is 5-10 mm, and the thickness of the dielectric substrate is 1 / 10-1 / 8 of the height of the metal frame.

[0016] The circularly polarized antenna for satellite communication of the metal frame smart terminal, wherein the length of the long strip-shaped through slot is 1 / 2-2 / 3 of the width of the metal frame.

[0017] The circularly polarized antenna for satellite communication of the metal frame smart terminal, wherein the width of the slot is 1 / 2-3 / 5 of the width of the long strip-shaped through slot.

[0018] In a second aspect, the embodiments of the present application further provide a smart terminal, wherein the smart terminal comprises a communication circuit and the circularly polarized antenna for satellite communication of the metal frame smart terminal as described in the first aspect above; and the communication circuit is electrically connected with the coaxial feed terminal to realize the transmission and reception of antenna signals.

[0019] The embodiment of the present application provides a circularly polarized antenna and a smart terminal for satellite communication of a metal-framed smart terminal, the circularly polarized antenna comprising a metal frame and a dielectric substrate arranged in the metal frame; metal floors are provided on both sides of the dielectric substrate, and the metal floors on both sides of the dielectric substrate are electrically connected through metallized through-holes; a gap is provided on the top of the metal frame to separate the metal frame; the end of the dielectric substrate close to the gap is not covered with the metal floor and forms a hollow opening; the metallized through-hole surrounds the end of the dielectric substrate close to the gap and combines with the hollow opening to form a magnetic dipole; the two metal floors at the magnetic dipole are respectively connected to the two separated connection ends in the metal frame through two parallel feed lines; the feed port is arranged on one side of the cavity close to the feed line. The above antenna is optimized and improved based on complementary dipoles, a magnetic dipole is formed by a cavity formed by metallized through-holes, and phase compensation is performed by two bent parallel feed lines, the end of the feed line is directly connected to the metal frame, and the top metal frame with a cross-shaped gap acts as an electric dipole, finally achieving a good end-fire circular polarization characteristic under the metal frame. The disclosed antenna is easy to process and has low cost. It also has the advantages of a metal frame, a single-layer structure, and an end-fire circularly polarized beam, and has good application effects in mobile terminals with satellite communication functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 A front structural diagram of a circularly polarized antenna for satellite communications of a metal-framed smart terminal provided in an embodiment of the present application;

[0022] Figure 2 Provided in the embodiments of this application Figure 1 Local structural diagram of area A in the middle;

[0023] Figure 3 A partial structural diagram of a circularly polarized antenna for satellite communications of a metal-framed smart terminal provided in an embodiment of the present application;

[0024] Figure 4 Another partial structural diagram of the circularly polarized antenna for satellite communication of a metal-framed smart terminal provided in an embodiment of the present application;

[0025] Figure 5 Another partial structural diagram of a circularly polarized antenna for satellite communications of a metal-framed smart terminal provided in an embodiment of the present application;

[0026] Figure 6 A cross-sectional structure diagram of a circularly polarized antenna for satellite communication of a metal frame intelligent terminal is provided for the embodiments of the present application.

[0027] Figure 7 A local structure diagram of a middle B area is provided for the embodiments of the present application. Figure 5

[0028] Figure 8 An effect schematic diagram of a circularly polarized antenna for satellite communication of a metal frame intelligent terminal is provided for the embodiments of the present application.

[0029] Figure 9 An effect schematic diagram of a circularly polarized antenna for satellite communication of a metal frame intelligent terminal is provided for the embodiments of the present application.

[0030] Figure 10 An effect schematic diagram of a circularly polarized antenna for satellite communication of a metal frame intelligent terminal is provided for the embodiments of the present application.

[0031] Figure 11 An effect schematic diagram of a circularly polarized antenna for satellite communication of a metal frame intelligent terminal is provided for the embodiments of the present application.

[0032] Fig. 1 is a metal frame; Fig. 2 is a dielectric substrate; Fig. 21 is a metal floor; Fig. 22 is a metalized via; Fig. 11 is a slit; Fig. 3 is a feed line; Fig. 12 is a long strip-shaped slot; Fig. 4 is a coaxial feed terminal; Fig. 41 is a feed port. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] It should be understood that when used in the specification and the appended claims, the terms "comprise" and "include" indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0035] It should also be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the present application specification and the appended claims, unless otherwise clearly indicated by the context, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0036] ​It should also be further understood that the term "and / or" used in the specification and the appended claims, means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0037] Referring to Figure 1 As shown in the figure, the application discloses a circularly polarized antenna for satellite communication of a metal frame intelligent terminal, which comprises a metal frame 1 and a dielectric substrate 2 arranged in the metal frame 1. Both sides of the dielectric substrate 2 are provided with metal floors 21, and the metal floors 21 on both sides of the dielectric substrate 2 are electrically connected through metallized through holes 22. The top of the metal frame 1 is provided with a gap 11, and the gap 11 separates the metal frame 1. One end of the dielectric substrate 2 close to the gap 11 is not covered with a metal floor 21 and forms a hollow opening. The metallized through holes 22 form a semi-enclosed cavity around one end of the dielectric substrate 2 close to the gap 11, and the cavity and the hollow opening form a magnetic dipole. The two metal floors 21 at the magnetic dipole are connected to the connecting ends in the metal frame 1 on both sides of the gap 11 through two parallel serpentine-shaped feed lines 3, respectively. The metal frame 1 is also provided with a long strip-shaped through slot 12 parallel to the dielectric substrate 2. The long strip-shaped through slot 12 intersects the gap 11 perpendicularly. A coaxial feed terminal 4 is arranged at a feed port 41 of the dielectric substrate 2 and connected to the two metal floors 21, respectively. The feed port 41 is arranged in the cavity close to one side of the feed line 3.

[0038] The circularly polarized antenna disclosed in the application mainly comprises two parts of a dielectric substrate 2 and a metal frame 1, and the planar design structure is as shown in the figure. Figure 1 Both sides of the dielectric substrate 2 are metal floors 21 of a PCB, and a metallized through hole 22 is designed in the dielectric substrate 2 to connect the metal floors 21 on both sides. The metallized through hole 22 forms a semi-enclosed cavity on one side of the hollow opening, thereby forming an equivalent magnetic dipole at the hollow opening. The diameter of the metallized through hole 22 is R1, and the distance between the edges of two adjacent metallized through holes 22 is G4, and the specific size is shown in the local enlarged view of the circle part in the figure. Figure 1

[0039] The metal floors 21 at the magnetic dipole are connected to the two connecting ends formed by the separation of the metal frame 1 through two feed lines 3, respectively. The feed line 3 is arranged in a serpentine shape, and the U-shaped bending structure formed on both sides of the feed line 3 has the same width except the connection with the metal frame 1. The U-shaped bending structure formed on both sides of the feed line 3 can be used to produce the required phase lag relative to the cavity magnetic dipole. The size of the feed line 3 is shown in the figure. Figure 2

[0040] ​​The metal frame 1 is only processed with a groove near the top of the hollowed-out opening. The longitudinal gap 11 directly penetrates the entire frame longitudinally. The transversely arranged long slot 12 is perpendicular to the gap 11. The length of the long slot 12 is L5. The specific structure of the feed line 3 connected to the two connection ends of the top metal frame 1 is shown in Figure 5 and Figure 7 . The upper and lower ends of the two parallel feed lines 3 are respectively connected to one connection end of the metal frame 1 and the corresponding metal floor 21. Among them, the dielectric substrate 2 can be made of Rogers4350B (ε r = 3.66 and tanδ = 0.0037). The dielectric substrate 2 serves as a substrate, and its thickness is H2.

[0041] Specifically, the diameter R1 of the metalized via hole 22 is 0.5-3mm, and in the preferred embodiment, the diameter R1 of the metalized via hole 22 can be set to 0.8-1.2mm. The spacing G4 between the edges of adjacent metalized via holes 22 is 1 / 3-1 / 2 of the diameter R1 of the metalized via hole 22. Among them, the metalized via hole 22 is arranged in a rectangular frame shape and forms a rectangular structure cavity with the hollowed-out opening. Further, the length L2 of the rectangular structure cavity is 5 / 7-3 / 4 of the width W1 of the metal frame, and the width W2 of the cavity is 2 / 7-1 / 3 of the length L2 of the cavity.

[0042] As shown in Figure 1 , the metalized via hole 22 can be arranged in a rectangular frame shape and form a semi-enclosed structure. The metalized via hole 22 and the hollowed-out opening form a rectangular structure cavity. To improve the feeding effect, the length L2 of the cavity can be set to 5 / 7-3 / 4 of the width W1 of the metal frame 1, and the width W2 of the cavity can be set to 2 / 7-1 / 3 of the length L2 of the cavity.

[0043] In a more specific embodiment, the distance L4 between the feed port 41 and the side of the cavity away from the feed line is 2 / 3-5 / 7 of the width W2 of the cavity.

[0044] The feed port 41 is located on one side of the cavity close to the feed line 3, and the change of the corresponding feed position of the feed port 41 directly affects the impedance matching. The feed port 41 is electrically connected to the coaxial feed terminal 4. The coaxial feed terminal 4 includes an inner terminal line and an outer terminal line. The specific structure is shown in Figure 3 and Figure 4 .

[0045] Specifically, the bending part of the feed line 3 is processed with an angle cut. The bending part of the transmission line is processed with an angle cut to reduce the loss on the transmission line and improve the radiation efficiency.

[0046] In a more specific embodiment, the height H1 of the metal frame 1 is 5-10 mm, and the thickness H2 of the dielectric substrate 2 is 1 / 10-1 / 8 of the height H1 of the metal frame 1. The length L5 of the long strip-shaped through slot 12 is 1 / 2-2 / 3 of the width W1 of the metal frame 1. Further, the width S2 of the gap 11 is 1 / 2-3 / 5 of the width S1 of the long strip-shaped through slot 12.

[0047] Further, the gap 11 and the long strip-shaped through slot 12 combine to form a cross-shaped gap, and the specific dimensions of the cross-shaped gap are shown in Figure 6 The specific design values of the dimensions are shown in Table 1:

[0048] Table 1 (dimension unit: mm)

[0049] <L1> <L2> <L3> ​ [L5] <L6> [CD AT W1] 152 56.5 16.4 11.5 47 0.2 77 [CD AT W2] [CD AT W3] [CD AT W4] [G1] [G2] [G3] [G4] 16.5 0.4 0.3 0.3 0.3 0.6 0.5 [G5] [G6] [R1] [H1] [H2]

[00100] S1 [S2] 1 2.7 1 6.5 0.762 0.7 0.4

[0050] wherein L1 is the length of the metal frame, L3 is the length of the middle microstrip line in the serpentine-shaped feed line, L6 is the horizontal width of the connection between the feed line and the connecting end, W3 is the width of the feed line, W4 is the vertical width of the connection between the feed line and the connecting end, G1 is the spacing between the bottom of the feed line and the metal floor, G2 is the spacing between the bottom microstrip line and the middle microstrip line in the feed line, G3 is the spacing between the top of the feed line and the metal frame, G5 is the thickness of the vertical side plate in the metal frame, and G6 is the gap value of the hollow opening (the spacing between the metal floor and the top metal frame).

[0051] The above-described end-fire circularly polarized mobile phone antenna is simulated and verified in the embodiments of the present application. The reflection coefficient of the antenna is shown in Figure 8 The reflection coefficient is less than -10 dB in the range of 2482-2508 MHz, completely covering the S-band (2483.5-2500 MHz) for Beidou navigation satellite signal reception. The axial ratio (AR) is usually used to describe the polarization purity of a circularly polarized antenna, and it is generally considered that an axial ratio lower than 3 dB indicates a high circular polarization purity of the antenna. The axial ratio test results of the antenna in the present application are shown in Figure 9 The axial ratio in the end-fire direction (+y direction) is lower than 3 dB in the range of 2457-2516 MHz, also covering the S-band for Beidou navigation satellite signal reception.

[0052] The total efficiency (Total Efficiency) of the end-fire circularly polarized mobile phone satellite antenna is shown in Figure 10 As can be seen from the figure, the total efficiency of the antenna is greater than 47% in the entire operating frequency band.

[0053] Since the receiving frequency band of the Beidou satellite navigation system is to receive the mobile terminal signal on the ground in the polarization mode of right-hand circular polarization, the antenna also works in the main polarization mode of right-hand circular polarization, and the left-hand circular polarization is used as the cross-polarization. The radiation pattern of the end-fire circularly polarized antenna disclosed in the application is shown in Figure 11 Figure 11 Fig. (a) is the radiation intensity of the antenna in the x-y plane and the y-z plane at a frequency of 2483.5 MHz, Figure 11 Fig. (b) is the radiation intensity of the antenna in the x-y plane and the y-z plane at a frequency of 2491 MHz, Figure 11 Fig. (c) is the radiation intensity of the antenna in the x-y plane and the y-z plane at a frequency of 2500 MHz; the red solid line represents the main polarization, i.e., the right-hand circular polarization, and the blue dotted line represents the cross-polarization, i.e., the left-hand circular polarization. It can be seen that the antenna has good directional radiation circular polarization effect at the three frequency points of 2483.5 MHz, 2491 MHz and 2500 MHz, and the cross-polarization is maintained at about -20 dB in the +y direction.

[0054] In addition, the antenna design disclosed in the application can be switched by simply replacing the main polarization and the cross-polarization. On the basis of the antenna, only the parts connected between the top of the metal frame and the double-wire parallel line feeders on the upper and lower layers of the dielectric substrate need to be exchanged, so that the polarization mode can be easily switched.

[0055] Finally, the new end-fire circularly polarized antenna based on the complementary dipole disclosed in the application is compared with other recently disclosed (documents 1 to 5) circularly polarized antennas for satellite communication of smart phones. The design of the application has the advantage of end-fire compared with the normal radiation antenna in the existing design (documents 4 and 5), and can be well applied to mobile terminal satellite communication. In addition, compared with the end-fire circularly polarized antenna in the existing design (documents 1 to 3), the design of the application has the same impedance bandwidth and axial ratio bandwidth, and also has a metal frame. Compared with the plastic material frame of the mobile phone, the design has stronger hardness and better aesthetics, and can bring better experience to the user.

[0056] ​Document 1: Z. Cao, L. Chang, Y. Li, K. Wei, and Z. Zhang, “Compact mobile terminal antenna with endfire circularly polarized beam for satellite communications,” IEEE Trans. Antennas Propag., vol. 71, no. 12, pp. 9980-9985, Dec. 2023; Document 2: X. Zhang, K. Wei, Y. Li, and Z. Zhang, “A circularly polarized antenna based on narrowed crossed dipole for smartphone satellite communication,” IEEE Antennas Wireless Propag. Lett., vol. 23, no. 8, pp. 2511-2515, Aug. 2024; Document 3: X. Zhang, K. Wei, Y. Li, and Z. Zhang, “A polarization reconfigurable antenna for satellite communication in foldable smartphone,” IEEE Trans. Antennas Propag., vol. 71, no. 12, pp. 9938-9943, Dec. 2023; Document 4: Y. Zhang, Y. Li, M. Hu, P. Wu, and H. Wang, “Dual-band circular-polarized microstrip antenna for ultrawideband positioning in smartphones with flexible liquid crystal polymer process,” IEEE Trans. Antennas Propag., vol. 71, no. 4, pp. 3155-3163, April 2023; Document 5: M. Hu, Y. Li, Y. Zhang, P. Wu, and H. Wang, “Ultrathin dual-band circularly polarized antenna,” IEEE Antennas Wireless Propag. Lett., vol. 23, no. 3, pp. 930-934, March 2024.

[0057] The application discloses a terminal-radiation circularly polarized mobile phone antenna applicable to mobile terminal satellite communication. The whole antenna is composed of a dielectric substrate with metal on both sides and a peripheral metal frame, wherein a cross-shaped cross slot is dug in the center of the top of the metal frame. The antenna is optimized and improved based on complementary dipoles, a magnetic dipole is formed by a cavity composed of metalized through holes, and phase compensation is performed by two curved parallel feed lines, the end of the feed line is directly connected to the metal frame, the top metal frame with the cross-shaped slot acts as an electric dipole, and finally good terminal-radiation circularly polarized characteristics are realized under the metal frame. The disclosed antenna is easy to process, low in cost, and has the advantages of metal frame, single-layer structure, terminal-radiation circularly polarized beam and the like, has good application effect in mobile terminals with satellite communication function, and shows great advantages in mobile terminal satellite communication application.

[0058] The application also discloses a smart terminal, wherein the smart terminal comprises a communication circuit and a circularly polarized antenna for satellite communication of a metal frame smart terminal as described in the above embodiments; the communication circuit is electrically connected with the coaxial feed terminal to realize the transmission and reception of antenna signals. The smart terminal in the application includes mobile phones, satellite phones, tablet computers, vehicle-mounted multimedia terminals and the like.

[0059] In the circularly polarized antenna for satellite communication of a metal frame smart terminal and the smart terminal provided by the application, the circularly polarized antenna comprises a metal frame and a dielectric substrate arranged in the metal frame; metal ground plates are arranged on both sides of the dielectric substrate, and the metal ground plates on both sides of the dielectric substrate are electrically connected through metalized through holes; a slot is arranged on the top of the metal frame, and the slot separates the metal frame; one end of the dielectric substrate close to the slot is not covered with a metal ground plate and forms a hollow opening; the metalized through holes surround one end of the dielectric substrate close to the slot and combine with the hollow opening to form a magnetic dipole; the two metal ground plates at the magnetic dipole are connected to two separated connection ends in the metal frame through two parallel feed lines; and a feed port is arranged on one side of the cavity close to the feed line. The antenna is optimized and improved based on complementary dipoles, a magnetic dipole is formed by a cavity composed of metalized through holes, and phase compensation is performed by two curved parallel feed lines, the end of the feed line is directly connected to the metal frame, the top metal frame with the cross-shaped slot acts as an electric dipole, and finally good terminal-radiation circularly polarized characteristics are realized under the metal frame. The disclosed antenna is easy to process, low in cost, and has the advantages of metal frame, single-layer structure, terminal-radiation circularly polarized beam and the like, has good application effect in mobile terminals with satellite communication function.

[0060] The above merely provides the specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A circularly polarized antenna for satellite communication of a metal frame intelligent terminal, characterized in that, The metal frame and the dielectric substrate arranged in the metal frame are provided. Both sides of the dielectric substrate are provided with metal ground plates, and the metal ground plates on both sides of the dielectric substrate are electrically connected through metallized vias; the top of the metal frame is provided with a gap, and the gap separates the metal frame; One end of the dielectric substrate close to the gap is not covered with a metal ground plate and forms a hollow opening; The metallized vias form a semi-enclosed cavity around one end of the dielectric substrate close to the gap, and the cavity and the hollow opening form a magnetic dipole; the two metal ground plates at the magnetic dipole are connected to the connection ends in the metal frame on both sides of the gap through two parallel serpentine feed lines, respectively; the metal frame is also provided with a long strip-shaped through slot parallel to the dielectric substrate; the long strip-shaped through slot and the gap are perpendicular to each other; Coaxial feed terminals are arranged at the feed ports of the dielectric substrate and are connected to the two metal ground plates, respectively, and the feed ports are arranged in the cavity close to one side of the feed line.

2. The circularly polarized antenna for satellite communication of metal frame smart terminal according to claim 1, characterized in that, The diameter of the metallized via is 0.5-3 mm, and the distance between the edges of adjacent metallized vias is 1 / 3-1 / 2 of the diameter of the metallized via.

3. The circularly polarized antenna for satellite communication of metal frame smart terminal according to claim 1 or 2, characterized in that, The metallized vias are arranged in a rectangular frame shape and form a rectangular structure cavity with the hollow opening.

4. The circularly polarized antenna for satellite communication of metal frame smart terminal according to claim 3, characterized in that, The length of the rectangular structure cavity is 5 / 7-3 / 4 of the width of the metal frame, and the width of the cavity is 2 / 7-1 / 3 of the length of the cavity.

5. The circularly polarized antenna for satellite communication of metal frame smart terminal according to claim 4, characterized in that, The distance between the feed port and the side of the cavity away from the feed line is 2 / 3-5 / 7 of the width of the cavity.

6. The circularly polarized antenna for satellite communication of metal frame smart terminal according to claim 3, characterized in that, The bending part of the feed line is chamfered.

7. The circularly polarized antenna for satellite communication of metal frame smart terminal according to claim 6, characterized in that, The height of the metal frame is 5-10 mm, and the thickness of the dielectric substrate is 1 / 10-1 / 8 of the height of the metal frame.

8. The circularly polarized antenna for satellite communication of metal frame smart terminal according to claim 7, characterized in that, The length of the long strip-shaped through slot is 1 / 2-2 / 3 of the width of the metal frame.

9. The circularly polarized antenna for satellite communication of metal frame smart terminal according to claim 8, characterized in that, The width of the gap is 1 / 2-3 / 5 of the width of the long strip-shaped through slot.

10. A smart terminal, characterized by The smart terminal includes a communication circuit and a circularly polarized antenna for a metal frame smart terminal satellite communication as claimed in any one of claims 1-9; The communication circuit is electrically connected to the coaxial feed terminals to realize the transmission and reception of antenna signals.

Images