Multiband patch antenna and communication device

Abstract

The application discloses a multi-band patch antenna and a communication device, and relates to the technical field of antennas. The multi-band patch antenna comprises a metal floor, a dielectric substrate, a radiator, a feed structure, a first capacitive structure, a short-circuit parasitic unit, a second capacitive structure and a plurality of second short-circuit columns. The first capacitive structure is used for reducing the main mode resonance frequency to a first frequency band; the second capacitive structure is arranged at the end of the short-circuit parasitic unit to increase the bandwidth of the first frequency band; and the plurality of second short-circuit columns are connected with the feed structure and the radiator to excite high-order mode resonance modes of a second frequency band and a third frequency band. The application can simultaneously cover multiple communication frequency bands under the condition of extremely small size, meets the strict space limitation of small-sized communication devices, overcomes the defects of large size, few frequency bands, narrow bandwidth, high profile, poor radiation performance and insufficient platform adaptability of traditional patch antennas, and is suitable for large-sized complete metal floor installation scenes, so that stable radiation and low cross-polarization characteristics of the multi-band patch antenna are ensured.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and in particular to a multi-band patch antenna and communication device. Background Technology

[0002] Miniaturized communication devices are evolving towards multifunctionality and high integration. Small-sized antennas need to meet requirements such as small size, multi-band coverage, low profile, high gain, and high efficiency. Patch antennas have become the mainstream solution for miniaturized antennas due to their small size, low cost, and ease of integration. However, traditional patch antennas have relatively large electrical dimensions in the low-frequency band, resulting in a large overall size and occupying more space in communication equipment. Moreover, most only achieve single-frequency or dual-frequency operation, making it difficult to cover the commonly used UHF, L, and S bands. At the same time, traditional patch antennas have narrow impedance bandwidths in each frequency band, affecting communication stability. While stacking or folding structures attempt to improve performance, they increase the installation volume, which is not conducive to the integration of communication equipment. In addition, the gain and efficiency of miniaturized patch antennas are often low, and they are difficult to adapt to large-size solid metal ground planes, resulting in insufficient radiation pattern stability, which limits their application in complex communication equipment. Summary of the Invention

[0003] The main objective of this invention is to propose a multi-band patch antenna and communication device that simultaneously covers multiple communication frequency bands under extremely small size conditions, meets the strict space constraints of miniaturized communication devices, overcomes the shortcomings of traditional patch antennas such as large size, few frequency bands, narrow bandwidth, high profile, poor radiation performance and insufficient platform adaptability, and is suitable for large-size complete metal floor installation scenarios, ensuring stable radiation and low cross-polarization characteristics of the multi-band patch antenna.

[0004] To achieve the above objectives, the present invention proposes a multi-band patch antenna, comprising: Metal flooring; A dielectric substrate is disposed on one side of the metal ground plane along the z-direction; A radiator is disposed on the side of the dielectric substrate away from the metal floor along the z-direction; A power feeding structure is disposed between the radiator and the dielectric substrate; A first capacitive structure is disposed between the radiator and the dielectric substrate, and located on one side of the feed structure along the x-direction. The first capacitive structure and the feed structure are arranged side by side along the x-direction. The first capacitive structure and the metal ground plane are separated by the dielectric substrate. The first capacitive structure is used to reduce the frequency of the main mode resonant mode of the multi-band patch antenna to the first frequency band. A short-circuit parasitic unit is disposed on one side of the radiator along the y-direction, and the side of the short-circuit parasitic unit closest to the metal floor is electrically connected to the metal floor through a first short-circuit post; A second capacitive structure is provided at one end of the short-circuit parasitic unit along the y-direction and away from the feeding structure, for increasing the bandwidth of the multi-band patch antenna in the first frequency band; Multiple second short-circuit posts are arranged in at least one row along the y-direction of the radiator and disposed between the feed structure and the radiator, for connecting the feed structure and the radiator in the second and third frequency bands, so as to couple radio frequency energy from the feed structure to the radiator to excite higher-order mode resonant modes in the second and third frequency bands; wherein the first frequency band is smaller than the second frequency band, and the second frequency band is smaller than the third frequency band.

[0005] In one embodiment, the multi-band patch antenna is a quarter-wavelength short-circuit patch; The sum of the widths of the radiator and the short-circuit parasitic unit in the y-direction is 40 mm; The length of both the radiator and the short-circuit parasitic unit in the x-direction is 40 mm.

[0006] In one embodiment, the first resilient structure is a first rectangular metal sheet; The first rectangular metal sheet is arranged parallel to the metal floor. By increasing the area of ​​the first rectangular metal sheet or decreasing the distance between the first rectangular metal sheet and the metal ground, the frequency of the master mode resonant mode can be reduced to the first frequency band.

[0007] In one embodiment, the second resilient structure is a second rectangular metal sheet; The first rectangular metal sheet is arranged parallel to the metal floor. The first frequency band has a first resonant point and a second resonant point; By adjusting the length of the first rectangular metal sheet and the width of the second rectangular metal sheet respectively, the positions of the first resonant point and the second resonant point are controlled, so that the first resonant point and the second resonant point are close to each other and coupled to each other, thereby increasing the bandwidth of the first frequency band.

[0008] In one embodiment, a plurality of the second short-circuit posts are arranged in two rows along the y-direction of the radiator; The two rows of the second short-circuit posts are staggered along the x-direction of the power supply structure.

[0009] In one embodiment, two rows of the second short-circuit posts are respectively arranged on both sides of the power supply structure along the x-direction.

[0010] In one embodiment, each row of second short-circuit posts is arranged at equal intervals, with a spacing of 1 mm between two adjacent second short-circuit posts.

[0011] In one embodiment, the radiator is provided with a radiation slot that extends along the x-direction of the radiator and is correspondingly arranged with the feeding structure. The radiation slot is located between the two rows of second short-circuit posts and is used to regulate the higher-order mode resonance modes of the second frequency band and the third frequency band.

[0012] In one embodiment, the dielectric substrate includes a first dielectric layer and a second dielectric layer, wherein the first dielectric layer and the second dielectric layer are stacked along the z-direction; And / or, the area of ​​the dielectric substrate is smaller than the area of ​​the metal floor.

[0013] The present invention also proposes a communication device, including the multi-band patch antenna as described above.

[0014] In this invention, by setting a first capacitive structure on one side of the feed structure along the x-direction and separating it from the metal ground plane using a dielectric substrate, the frequency of the main mode resonant mode of the multi-band patch antenna is reduced to the first frequency band. This helps to reduce the electrical size of the multi-band patch antenna in the low-frequency band, thereby reducing the overall volume. This invention also improves the problem of narrow impedance bandwidth in traditional patch antennas by setting a short-circuit parasitic unit electrically connected to the metal ground plane via a first short-circuit post, and setting a second capacitive structure at the end of the short-circuit parasitic unit along the y-direction and away from the feed structure. The second capacitive structure increases the bandwidth of the multi-band patch antenna in the first frequency band. Simultaneously, by arranging multiple second short-circuit posts in at least one row along the y-direction of the radiator and placing them between the feed structure and the radiator, the feed structure and the radiator are connected in the second and third frequency bands to couple radio frequency energy from the feed structure to the radiator, exciting higher-order mode resonant modes in the second and third frequency bands, enabling the multi-band patch antenna to cover three frequency bands. This configuration allows the multi-band patch antenna to achieve multi-band coverage and bandwidth expansion while maintaining a small size and low profile. It avoids the increased installation volume caused by stacking or folding structures, which helps to improve the gain and efficiency of the multi-band patch antenna and enhances the stability of the radiation pattern when the multi-band patch antenna is adapted to a large-size solid metal floor, thereby better meeting the integration needs of miniaturized communication devices. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the multi-band patch antenna of the present invention; Figure 2 This is a side view of the multi-band patch antenna of the present invention; Figure 3 This is a parameter diagram of the multi-band patch antenna of the present invention; Figure 4 This is a simulation curve of the multi-band patch antenna of the present invention.

[0017] Explanation of icon numbers: 100. Multi-band patch antenna; 10. Metal ground plane; 20. Dielectric substrate; 30. Radiator; 3001. Radiating slot; 40. Feed structure; 50. First capacitive structure; 60. Short-circuit parasitic element; 70. Second capacitive structure; 80. Second short-circuit post.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Miniaturized communication devices are evolving towards multifunctionality and high integration. Small-sized antennas need to meet requirements such as small size, multi-band coverage, low profile, high gain, and high efficiency. Patch antennas have become the mainstream solution for miniaturized antennas due to their small size, low cost, and ease of integration. However, traditional patch antennas have relatively large electrical dimensions in the low-frequency band, resulting in a large overall size and occupying more space in communication equipment. Moreover, most only achieve single-frequency or dual-frequency operation, making it difficult to cover the commonly used UHF, L, and S bands. At the same time, traditional patch antennas have narrow impedance bandwidths in each frequency band, affecting communication stability. While stacking or folding structures attempt to improve performance, they increase the installation volume, which is not conducive to the integration of communication equipment. In addition, the gain and efficiency of miniaturized patch antennas are often low, and they are difficult to adapt to large-size solid metal ground planes, resulting in insufficient radiation pattern stability, which limits their application in complex communication equipment.

[0021] This invention proposes a multi-band patch antenna 100.

[0022] Please see Figure 1 and Figure 2 In one embodiment of the present invention, the multi-band patch antenna 100 includes: Metal floor 10; The dielectric substrate 20 is disposed on one side of the metal ground plane 10 along the z-direction; The radiator 30 is disposed on the side of the dielectric substrate 20 away from the metal floor 10 along the z-direction; The power feeding structure 40 is disposed between the radiator 30 and the dielectric substrate 20; The first capacitive structure 50 is disposed between the radiator 30 and the dielectric substrate 20, and is located on one side of the feed structure 40 along the x-direction. The first capacitive structure 50 and the feed structure 40 are arranged side by side along the x-direction. The first capacitive structure 50 and the metal ground plane 10 are separated by the dielectric substrate 20, and are used to reduce the frequency of the main mode resonant mode of the multi-band patch antenna 100 to the first frequency band. The short-circuit parasitic unit 60 is located on one side of the radiator 30 along the y direction. The side of the short-circuit parasitic unit 60 closest to the metal floor 10 is electrically connected to the metal floor 10 through the first short-circuit post. The second capacitive structure 70 is located at one end of the short-circuit parasitic unit 60 along the y-direction and away from the feed structure 40, and is used to increase the bandwidth of the multi-band patch antenna 100 in the first frequency band. Multiple second short-circuit posts 80 are arranged in at least one row along the y-direction of the radiator 30 and disposed between the feed structure 40 and the radiator 30. They are used to connect the feed structure 40 and the radiator 30 in the second and third frequency bands, so as to couple radio frequency energy from the feed structure 40 to the radiator 30 to excite higher-order mode resonance modes in the second and third frequency bands. The first frequency band is smaller than the second frequency band, and the second frequency band is smaller than the third frequency band.

[0023] In this embodiment, the metal ground plane 10 serves as the reference ground plane for the multi-band patch antenna 100. It forms stable electromagnetic boundary conditions and reflects rearward-radiated electromagnetic waves, thereby improving the forward radiation gain and radiation pattern stability of the multi-band patch antenna 100. Simultaneously, the metal ground plane 10 provides an installation interface for the multi-band patch antenna 100 to accommodate installation scenarios with large-size, complete metal ground planes. To achieve a low-profile design for the multi-band patch antenna 100 and maintain electrical insulation between the metal ground plane 10 and the radiator 30, a dielectric substrate 20 is provided on one side of the metal ground plane 10 along the z-direction. The dielectric substrate 20 supports the radiator 30 while isolating the metal ground plane 10 from the radiator 30, preventing direct contact between the radiator 30 and the metal ground plane 10 and potential short circuits. Furthermore, the dielectric constant of the dielectric substrate 20 shortens the operating wavelength of the multi-band patch antenna 100, which is beneficial for further reducing the physical size of the multi-band patch antenna 100. A radiator 30 is disposed on the side of the dielectric substrate 20 away from the metal ground plane 10 along the z-direction. The radiator 30 can be implemented by etching a pattern on copper foil or by using a conductive metal patch. The radiator 30 is the core resonant component of the multi-band patch antenna 100, used to generate electromagnetic resonance at a specific frequency and radiate radio frequency energy into free space. A feed structure 40 is disposed between the radiator 30 and the dielectric substrate 20. The feed structure 40 can be implemented by using a microstrip transmission line or a coaxial probe. The function of the feed structure 40 is to transmit external radio frequency signals to the radiator 30, exciting the radiator 30 to generate the electromagnetic resonance mode of the required frequency band, so that the multi-band patch antenna 100 can operate normally.

[0024] To overcome the drawback of large electrical dimensions in the low-frequency band of traditional patch antennas, and to reduce the frequency of the main mode resonant mode of the multi-band patch antenna 100 to cover the first frequency band (UHF band), a first capacitive structure 50 is disposed between the radiator 30 and the dielectric substrate 20. The first capacitive structure 50 can be implemented using an additional metal patch or a lumped capacitor element. The first capacitive structure 50 is located on one side of the feed structure 40 along the x-direction and is arranged side-by-side with the feed structure 40 along the x-direction, forming a strongly coupled capacitor region between the first capacitive structure 50 and the feed structure 40. This effectively increases the equivalent electrical length without significantly increasing the physical size of the multi-band patch antenna 100, thereby reducing the frequency of the main mode resonant mode of the multi-band patch antenna 100. The first capacitive structure 50 and the metal ground plane 10 are separated by a dielectric substrate 20, that is, the dielectric substrate 20 is located between the first capacitive structure 50 and the metal ground plane 10. The dielectric properties of the dielectric substrate 20 are used to enhance the capacitive loading effect, so that the frequency of the main mode resonant mode of the multi-band patch antenna 100 is reduced to the first frequency band, thereby realizing the miniaturization of the multi-band patch antenna 100 in the UHF band and alleviating the problem that traditional patch antennas occupy too much space in communication equipment.

[0025] However, relying solely on the first capacitive structure 50 for capacitive loading results in a relatively narrow operating bandwidth in the UHF band, which cannot meet the actual communication needs of communication equipment. To extend the operating bandwidth of the UHF band, a short-circuit parasitic unit 60 is provided on one side of the radiator 30 along the y-direction. The short-circuit parasitic unit 60 can be implemented using a metal strip or a conductive sheet. The side of the short-circuit parasitic unit 60 closest to the metal ground plane 10 is electrically connected to the metal ground plane 10 via a first short-circuit post, causing the short-circuit parasitic unit 60 to form an inductive load and generate electromagnetic coupling with the radiator 30. This introduces an additional resonant path to broaden the impedance bandwidth of the multi-band patch antenna 100 in the UHF band, improving the poor communication stability caused by the narrow impedance bandwidth of traditional patch antennas in each frequency band. A second capacitive structure 70 is provided at the end of the short-circuit parasitic unit 60 along the y-direction and away from the feed structure 40. The second capacitive structure 70 can be implemented using a metal patch or a lumped capacitor. A second capacitive structure 70 is provided at the end of the short-circuit parasitic unit 60 along the y-direction and away from the feed structure 40. This allows for fine adjustment of the resonant characteristics of the short-circuit parasitic unit 60 and its coupling strength with the radiator 30, further increasing the bandwidth of the multi-band patch antenna 100 in the UHF band. This enables the multi-band patch antenna 100 to have a wider usable bandwidth in the UHF band, improving the communication reliability of communication equipment in complex electromagnetic environments.

[0026] To maintain the performance of the UHF band while increasing the coverage of the second and third bands, the second band is the L band and the third band is the S band. Multiple second short-circuit posts 80 are provided between the power supply structure 40 and the radiator 30. Multiple second short-circuit posts 80 are arranged in at least one row along the y-direction of the radiator 30. This arrangement is because the surface current distribution of the radiator 30 exhibits a specific standing wave pattern along the y-direction in the high-order mode resonance modes of the L-band and S-band. Arranging multiple second short-circuit posts 80 in at least one row along the y-direction of the radiator 30 ensures that the positions of the multiple second short-circuit posts 80 correspond to the positions where the current amplitude of the high-order mode resonance mode reaches its maximum value. This enhances the electromagnetic coupling efficiency between the feed structure 40 and the radiator 30 in the L-band and S-band. At the same time, arranging multiple second short-circuit posts 80 in at least one row along the y-direction of the radiator 30 can also regulate the high-order mode current distribution on the radiator 30, improve the impedance matching characteristics of the multi-band patch antenna 100 in the L-band and S-band, and suppress unnecessary spurious modes, making the radiation performance of the multi-band patch antenna 100 in the L-band and S-band more stable. Multiple second short-circuit posts 80 are used to connect the feed structure 40 and the radiator 30 in the L-band and S-band. Analysis shows that the second short-circuit post 80 exhibits high impedance characteristics in the UHF band, meaning that the electrical length of the second short-circuit post 80 in the UHF band is much less than a quarter wavelength, making the second short-circuit post 80 equivalent to an open circuit. Therefore, it has almost no impact on the aforementioned main mode resonant mode and its bandwidth extension in the UHF band. However, in the L-band and S-band, the second short-circuit post 80 exhibits low impedance characteristics, meaning that the electrical length of the second short-circuit post 80 in the L-band and S-band is close to a quarter wavelength, making the second short-circuit post 80 equivalent to a short circuit. This becomes an effective feed path, coupling radio frequency energy from the feed structure 40 to the radiator 30, thereby exciting higher-order mode resonant modes in the second and third bands. With this configuration, the present invention can achieve effective coverage of the UHF, L, and S frequency bands with an extremely small electrical size of 0.118λL×0.118λL×0.015λL, and each frequency band has a usable impedance bandwidth. This avoids the increase in installation volume caused by using stacked or folded structures, helps maintain the low profile characteristics of the multi-band patch antenna 100, improves the gain and efficiency of the multi-band patch antenna 100, and enhances the radiation pattern stability of the multi-band patch antenna 100 when adapted to a large-size solid metal ground plane 10, so as to meet the integration requirements of miniaturized communication devices.

[0027] In the technical solution of this invention, by setting the first capacitive structure 50 on one side of the feed structure 40 along the x-direction and spaced from the metal ground plane 10 by the dielectric substrate 20, the frequency of the main mode resonant mode of the multi-band patch antenna 100 is reduced to the first frequency band, which helps to reduce the electrical size of the multi-band patch antenna 100 in the low-frequency band, thereby reducing the overall volume. This invention also improves the problem of narrow impedance bandwidth of traditional patch antennas by setting the short-circuit parasitic unit 60 electrically connected to the metal ground plane 10 via the first short-circuit post and setting the second capacitive structure 70 at the end of the short-circuit parasitic unit 60 along the y-direction and away from the feed structure 40. The second capacitive structure 70 increases the bandwidth of the multi-band patch antenna 100 in the first frequency band. Simultaneously, by arranging multiple second short-circuit posts 80 in at least one row along the y-direction of the radiator 30 and placing them between the feed structure 40 and the radiator 30, the feed structure 40 and the radiator 30 are connected in the second and third frequency bands to couple radio frequency energy from the feed structure 40 to the radiator 30, thereby exciting higher-order mode resonant modes in the second and third frequency bands. This allows the multi-band patch antenna 100 to cover three frequency bands. This configuration enables the multi-band patch antenna 100 to achieve multi-band coverage and bandwidth expansion while maintaining a small size and low profile. It avoids the increased installation volume caused by stacked or folded structures, which is beneficial for improving the gain and efficiency of the multi-band patch antenna 100 and enhances the stability of the radiation pattern when the multi-band patch antenna 100 is adapted to a large-size solid metal ground plane 10, thus better meeting the integration requirements of miniaturized communication devices.

[0028] like Figure 1 and Figure 2 As shown, in one embodiment, the multi-band patch antenna 100 is a quarter-wavelength short-circuit patch antenna; The sum of the widths of the radiator 30 and the short-circuit parasitic unit 60 in the y direction is 40 mm; The length of both the radiator 30 and the short-circuit parasitic unit 60 in the x-direction is 40 mm.

[0029] In this embodiment, according to the cavity model theory, the multi-band patch antenna 100, when the second short-circuit post 80 is not loaded, its Odd mode belongs to a higher-order mode resonance mode. In this mode, the electric field exhibits an anti-phase distribution along the length of the multi-band patch antenna 100, resulting in lower radiation efficiency and larger size. Through the central plane of the multi-band patch antenna 100 (i.e., By setting multiple second short-circuit pillars 80 on the zero potential surface of the odd mode's electric field, the high-order mode resonance mode can be forcibly truncated and transformed using short-circuit boundary conditions. Semi-modal operating state. From the perspective of mode evolution, this... The half-mode is equivalent to the dominant mode resonant mode of a traditional rectangular patch in terms of electromagnetic field distribution, current path, and radiation characteristics. However, it only utilizes half of the original higher-order mode physical structure for resonance. Therefore, this transformation from "higher-order mode" to "equivalent dominant mode" allows the multi-band patch antenna 100 to obtain the high radiation efficiency and stable impedance characteristics of the dominant mode resonance mode while maintaining the original external dimensions. At the same time, in this equivalent dominant mode operating state, the resonant frequency of the multi-band patch antenna 100 is determined by its width and length, thereby achieving flexible control of the resonant frequency without increasing the area.

[0030] Based on the theoretical foundation of converting higher-order modes into equivalent dominant mode resonant modes described above, this embodiment further implements this through a specific size configuration. Since the multi-band patch antenna 100 adopts a quarter-wavelength short-circuit patch structure, the sum of the widths of its radiator 30 and short-circuit parasitic element 60 in the y-direction is set to 40mm, and their lengths in the x-direction are both set to 40mm. This results in a theoretical resonant frequency of approximately 0.947GHz for the multi-band patch antenna 100 without considering edge effects. This theoretical calculation demonstrates the effectiveness of the aforementioned equivalent dominant mode conversion mechanism; that is, the quarter-wavelength short-circuit patch structure of the multi-band patch antenna 100 can achieve lower-frequency electromagnetic resonance within a limited physical size, which is beneficial for reducing the overall volume of the multi-band patch antenna 100 to adapt to the space constraints of miniaturized communication devices.

[0031] Based on the operating characteristics of the equivalent master mode, the radiator 30 and the short-circuit parasitic element are both 40mm wide in the y direction and 40mm long in the x direction. This design makes the radiator 30 physically symmetrical, which helps maintain the symmetry of the current distribution of the multi-band patch antenna 100 in the master mode resonance mode, reduces the cross-polarization components caused by structural asymmetry, and improves the purity of the radiation pattern of the multi-band patch antenna 100.

[0032] Furthermore, the theoretical resonant frequency at this size is approximately 0.947 GHz, which is close to the frequency range of the UHF band. This ensures that the capacitive loading required by the first capacitive structure 50 is within a reasonable range, avoiding a significant decrease in the radiation efficiency of the multi-band patch antenna 100 due to excessive capacitive loading or an inability to effectively reduce the frequency of the main mode resonant mode to the UHF band due to insufficient capacitive loading. Thus, while reducing the physical size of the multi-band patch antenna 100, its basic radiation performance in the UHF band is maintained.

[0033] like Figure 1 and Figure 2 As shown, in one embodiment, the first resilient structure 50 is a first rectangular metal sheet; The first rectangular metal sheet is set parallel to the metal floor 10; By increasing the area of ​​the first rectangular metal sheet or decreasing the distance between the first rectangular metal sheet and the metal ground plate 10, the frequency of the main mode resonant mode can be reduced to the first frequency band.

[0034] In this embodiment, to reduce the frequency of the main mode resonant mode of the multi-band patch antenna 100 to cover the first frequency band, the first capacitive structure 50 is composed of a first rectangular metal sheet arranged parallel to the metal ground plane 10. The first rectangular metal sheet and the metal ground plane 10 are separated by a dielectric substrate 20 to form an equivalent planar capacitor structure. According to the planar capacitor formula C=εS / d, increasing the area S of the first rectangular metal sheet or decreasing the distance d between the first rectangular metal sheet and the metal ground plane 10 will increase the equivalent capacitance C of the first capacitive structure 50, thereby extending the equivalent electrical length of the multi-band patch antenna 100 and shifting the frequency of the main mode resonant mode of the multi-band patch antenna 100 towards lower frequencies. By adjusting the geometric parameters of the first rectangular metal sheet to achieve frequency tuning, the multi-band patch antenna 100 can reduce the frequency of the main mode resonant mode to the first frequency band without significantly increasing its physical size, effectively alleviating the problem of large overall volume caused by the large electrical size of traditional patch antennas in the low-frequency band. Meanwhile, the parallel arrangement of the first rectangular metal sheet and the metal ground plane 10 helps maintain the uniformity of the electromagnetic field distribution inside the multi-band patch antenna 100, avoiding additional radiation loss introduced by the asymmetric loading of the first capacitive structure 50 or edge electric field distortion. This helps maintain the gain and efficiency of the multi-band patch antenna 100 in the first frequency band, enabling the multi-band patch antenna 100 to meet the RF performance requirements of communication equipment while achieving miniaturization. Furthermore, by adjusting the area S of the first rectangular metal sheet or the distance d between the first rectangular metal sheet and the metal ground plane 10, the equivalent capacitance C of the first capacitive structure 50 can be adjusted, providing a flexible adjustment method for the frequency design of the multi-band patch antenna 100. This facilitates precise tuning of the multi-band patch antenna 100 according to the specific frequency value of the target first frequency band in practical engineering, thereby improving the adaptability of the multi-band patch antenna 100 to different first frequency band applications.

[0035] In the single-resonant-point operating mode formed solely by the first capacitive structure 50, the operating bandwidth of the multi-band patch antenna 100 in the first frequency band is still relatively narrow, making it difficult to meet actual communication needs.

[0036] like Figure 1 and Figure 2 As shown, in one embodiment, the second resilient structure 70 is a second rectangular metal sheet; The first rectangular metal sheet is set parallel to the metal floor 10; The first frequency band has a first resonant point and a second resonant point; By adjusting the length of the first rectangular metal sheet and the width of the second rectangular metal sheet respectively, the positions of the first resonant point and the second resonant point are controlled, so that the first resonant point and the second resonant point are close to each other and coupled together, thereby increasing the bandwidth of the first frequency band.

[0037] In this embodiment, to extend the operating bandwidth of the first frequency band, the side of the short-circuit parasitic unit 60 closest to the metal ground plane 10 is electrically connected to the metal ground plane 10 via a first short-circuit post, enabling the short-circuit parasitic unit 60 to generate a resonant mode independent of the main mode, thereby giving the first frequency band a first resonant point and a second resonant point. Since the first rectangular metal sheet, as the first capacitive structure 50, is directly loaded between the radiator 30 and the dielectric substrate 20, it mainly participates in and adjusts the resonant characteristics of the radiator 30. Therefore, the position of the first resonant point is mainly determined by the geometric parameters of the first rectangular metal sheet. The second rectangular metal sheet is disposed at the end of the short-circuit parasitic unit 60 along the y-direction and away from the feed structure 40, mainly affecting the resonant characteristics of the short-circuit parasitic unit 60 and its coupling strength with the radiator 30. Therefore, the position of the second resonant point is mainly determined by the geometric parameters of the second rectangular metal sheet. The two resonant modes are relatively independent in physical space and electromagnetic path, allowing the first rectangular metal sheet and the second rectangular metal sheet to respectively target and regulate the first and second resonant points without significant mutual interference. Therefore, by adjusting the length of the first rectangular metal plate and the width of the second rectangular metal plate respectively, the positions of the first and second resonant points can be independently controlled. When the first and second resonant points are close to each other on the frequency axis, a strong electromagnetic coupling effect is generated between the two resonant modes, merging the originally separate single-point narrowband response into a continuous double-peak broadband response, thereby effectively increasing the impedance bandwidth of the multi-band patch antenna 100 in the first frequency band. By using the first and second rectangular metal plates to control the dual resonant points respectively, the multi-band patch antenna 100 can achieve a significant expansion of the first frequency band bandwidth without adding additional stacking or folding structures, which is beneficial to maintaining the low profile characteristics and miniaturization advantages of the multi-band patch antenna 100. Meanwhile, the layout of the first and second rectangular metal plates being arranged parallel to the metal ground plane 10 helps to maintain the symmetry of the electric field distribution inside the multi-band patch antenna 100, reduces the radiation pattern distortion introduced by the bandwidth expansion, and enables the multi-band patch antenna 100 to maintain good radiation efficiency and pattern stability while widening the bandwidth of the first frequency band, thus better adapting to the application requirements of miniaturized communication equipment for stable UHF band communication.

[0038] like Figure 1 and Figure 2 As shown, in one embodiment, a plurality of second short-circuit posts 80 are arranged in two rows along the y-direction of the radiator 30; The two rows of second short-circuit posts 80 are staggered along the x-direction of the power supply structure 40.

[0039] In this embodiment, to increase the coverage of the second and third frequency bands while maintaining the performance of the first frequency band, multiple second short-circuit posts 80 are provided between the feed structure 40 and the radiator 30. Since the second short-circuit posts 80 exhibit high impedance characteristics in the first frequency band, which is equivalent to an open circuit, they have almost no impact on the TM0, 1 / 2 modes and their bandwidth extension in the first frequency band. However, in the second and third frequency bands, the second short-circuit posts 80 exhibit low impedance characteristics, which is equivalent to a short circuit, becoming an effective feed path that couples radio frequency energy from the feed structure 40 to the radiator 30, thereby exciting higher-order mode resonant modes. Based on this, to better achieve impedance matching of the multi-band patch antenna 100, multiple second short-circuit posts 80 are arranged in two rows along the y-direction of the radiator 30, and the two rows of second short-circuit posts 80 are staggered along the x-direction of the feed structure 40. This creates an asymmetrical coupling path in space, which helps to adjust the coupling strength and phase relationship between the feed structure 40 and the radiator 30 in different frequency bands. This makes it easier to match the input impedance of the multi-band patch antenna 100 to the target resistance value in the second and third frequency bands, reducing reflection loss caused by multi-mode coexistence. At the same time, the staggered arrangement of the two rows of second short-circuit posts 80 along the x-direction of the feed structure 40 avoids excessive mutual coupling effect in the high-frequency band, helps maintain the relative independence between each resonant mode, and allows the multi-band patch antenna 100 to maintain the original bandwidth and radiation performance of the first frequency band without significant interference while expanding the coverage of the second and third frequency bands. In addition, the multiple second short-circuit pillars 80 are arranged in two rows along the y-direction of the radiator 30, which increases the effective coupling area between the feed structure 40 and the radiator 30, improves the efficiency of radio frequency energy transmission to the radiator 30, and improves the gain of the multi-band patch antenna 100 in the second and third frequency bands, better meeting the application requirements of miniaturized communication equipment for efficient and stable multi-band communication.

[0040] like Figure 1 and Figure 2 As shown, in one embodiment, two rows of second short-circuit posts 80 are respectively arranged on both sides of the power supply structure 40 along the x direction.

[0041] In this embodiment, two rows of second short-circuit posts 80 are respectively arranged on both sides of the feed structure 40 along the x-direction, such that one side of the feed structure 40 along the x-direction corresponds to one row of second short-circuit posts 80, and the other side of the feed structure 40 along the x-direction corresponds to another row of second short-circuit posts 80. This arrangement allows the two rows of second short-circuit posts 80 to form spatially separated coupling channels on both sides of the feed structure 40 along the x-direction, which helps to disperse the electromagnetic energy transmission area between the feed structure 40 and the radiator 30 along the x-direction, and avoids excessive concentration of radio frequency energy at the center of the feed structure 40, which would cause excessively high local field strength and mode perturbation. Meanwhile, the two rows of second short-circuit posts 80 are located on both sides of the feed structure 40 along the x-direction, which allows the radio frequency energy to obtain a more sufficient excitation range along the x-direction when it is transmitted from the feed structure 40 to the radiator 30. This improves the radiation efficiency and pattern stability of the multi-band patch antenna 100 in the second and third frequency bands, and helps to reduce the mutual coupling interference between the two rows of second short-circuit posts 80. It also maintains the relative independence of each resonant mode, so that while expanding the coverage of the second and third frequency bands, the multi-band patch antenna 100 can still maintain the original bandwidth and radiation performance of the first frequency band without significant impact, thus better adapting to the application requirements of miniaturized communication equipment for stable multi-band communication.

[0042] like Figure 1 and Figure 2 As shown, in one embodiment, each row of second short-circuit posts 80 is equidistantly spaced, and the interval between two adjacent second short-circuit posts 80 is 1 mm.

[0043] In this embodiment, each row of second short-circuit posts 80 is arranged at equal intervals, and the spacing between two adjacent second short-circuit posts 80 is set to 1 mm. This ensures that the coupling channel formed by each row of second short-circuit posts 80 along the radiator 30y direction has a uniform periodic structural feature, which is beneficial for maintaining a stable phase progression relationship when radio frequency energy is transmitted from the feed structure 40 to the radiator 30, and reducing local impedance fluctuations and mode disturbances caused by uneven spacing. At the same time, the 1 mm spacing between two adjacent second short-circuit posts 80 can maintain a sufficient number of coupling elements in a limited space, enabling the multi-band patch antenna 100 to obtain a more continuous equivalent feed path in the second and third frequency bands, thereby improving the high-frequency excitation efficiency and bandwidth expansion capability. Furthermore, this equidistant and fixed-interval arrangement helps reduce the impact of machining tolerances on electromagnetic performance, making it easier for the multi-band patch antenna 100 to maintain the designed resonant characteristics and matching state during actual manufacturing. This allows it to expand the coverage of the second and third frequency bands while maintaining the original bandwidth and radiation performance of the first frequency band without significant interference, thus better adapting to the application requirements of miniaturized communication equipment for stable multi-band communication.

[0044] like Figure 1 and Figure 2As shown, in one embodiment, the radiator 30 is provided with a radiation slot 3001, which extends along the x-direction of the radiator 30 and is correspondingly provided with the power supply structure 40. The radiation slot 3001 is located between two rows of second short-circuit posts 80 and is used to regulate the higher-order mode resonance modes of the second and third frequency bands.

[0045] In this embodiment, the radiating slot 3001 is located at the center of the radiator 30 along the x-direction, and extends along the x-direction of the radiator 30, corresponding to the feeding structure 40. Since the radiating slot 3001 is located between the two rows of second short-circuit posts 80, the radiating slot 3001 and the two rows of second short-circuit posts 80 form a synergistic relationship in space, jointly perturbing the high-frequency current distribution on the surface of the radiator 30. This perturbation alters the continuity of the original current path, making it easier for radio frequency energy to couple to higher-order mode resonance states in the second and third frequency bands, thereby stably exciting the higher-order mode resonance modes in the second and third frequency bands. Simultaneously, the layout of the radiating slot 3001 extending along the x-direction of the radiator 30 and located between the two rows of second short-circuit posts 80 makes the field strength distribution of higher-order modes more concentrated in the central region of the radiator 30, which is beneficial for improving the radiation efficiency and mode purity of the second and third frequency bands. Furthermore, by adjusting the size and position of the radiation slot 3001, the resonant frequency and impedance matching characteristics of the higher-order mode can be further fine-tuned, so that while expanding the coverage of the second and third frequency bands, the multi-band patch antenna 100 can still maintain the original bandwidth and radiation performance of the first frequency band without significant interference, thus better adapting to the application requirements of miniaturized communication equipment for stable multi-band communication.

[0046] like Figure 1 and Figure 2 As shown, in one embodiment, the dielectric substrate 20 includes a first dielectric layer and a second dielectric layer, which are stacked along the z-direction.

[0047] In this embodiment, the dielectric substrate 20 is composed of a first dielectric layer and a second dielectric layer stacked along the z-direction. Compared with a single integral dielectric substrate 20, this layered structure avoids the increased process difficulty and cost associated with processing blind vias on thick dielectric materials. When the dielectric substrate 20 is an integral structure, the depth of blind vias required for internal interconnection or grounding is large, making it difficult to control processing accuracy and prone to electrical performance fluctuations due to drilling deviations. By dividing the dielectric substrate 20 into a first dielectric layer and a second dielectric layer, each layer can be processed with through-holes or shallow holes, and then interlayer interconnection is completed through alignment and lamination, significantly reducing manufacturing complexity. At the same time, the stacking of the first and second dielectric layers along the z-direction allows the thickness of each layer to be independently selected according to RF performance requirements, which is beneficial for optimizing the equivalent dielectric constant and impedance matching characteristics of the multi-band patch antenna 100 in different frequency bands.

[0048] like Figure 1 and Figure 2 As shown, in one embodiment, the area of ​​the dielectric substrate 20 is smaller than the area of ​​the metal floor 10.

[0049] In this embodiment, the outline dimensions of the dielectric substrate 20 are designed to be smaller than those of the metal ground plane 10, so that the metal ground plane 10 forms an extended region on the outer side of the edge of the dielectric substrate 20. This extended region allows the metal ground plane 10 to cover the space outside the boundary of the dielectric substrate 20, which helps to reduce the leakage of radio frequency energy from the side of the dielectric substrate 20 and reduce the adverse effects of edge diffraction on the radiation pattern of the multi-band patch antenna 100. At the same time, the layout of the dielectric substrate 20 having a smaller area than the metal ground plane 10 allows the metal ground plane 10 to serve as a more complete reference ground plane, improving the impedance matching state between the feed structure 40 and the radiator 30, and reducing the resonant frequency shift and loss increase caused by incomplete grounding. In addition, this dimensional relationship also helps to reserve sufficient fixing or welding area for the metal ground plane 10 during assembly, improving the structural stability of the multi-band patch antenna 100 in practical applications.

[0050] like Figures 1 to 3 As shown, in one embodiment, the sum of the widths of the radiator 30 and the short-circuit parasitic unit 60 in the y-direction is 40 mm, the lengths of the radiator 30 and the short-circuit parasitic unit 60 in the x-direction are both 40 mm, the thickness H of the dielectric substrate 20 in the z-direction is 5 mm, the first dielectric layer is the upper dielectric layer with a thickness of 1.2 mm in the z-direction, the second dielectric layer is the lower dielectric layer with a thickness of 3.8 mm in the z-direction, the spacing d between the first capacitive structure 50 and the metal ground plane 10 is 3.8 mm, the width W1 of the first capacitive structure 50 in the y-direction is 38.7 mm, and the first capacitive structure... The length Wcf1 of structure 50 in the x direction is 8mm, the width L of short-circuit parasitic unit 60 in the x direction is 40mm, the length W2 of short-circuit parasitic unit 60 in the x direction is 1.1mm, the width Wcf2 of second capacitive structure 70 in the y direction is 14.2mm, the width Wf of feed structure 40 in the y direction is 38mm, L is the length Lf of feed structure 40 in the x direction is 14.8mm, the spacing Dv between two adjacent second short-circuit posts 80 is 1mm, the width Ls of radiation slot 3001 in the y direction is 21mm, and the length Ws of radiation slot 3001 in the x direction is 1mm.

[0051] Based on the above dimensional parameters, simulation experiments have verified that, as Figure 4As shown, the multi-band patch antenna 100 has a coverage range of 0.889 GHz to 0.924 GHz in the UHF band, with a bandwidth of 35 MHz, a relative bandwidth of 4.0%, a maximum gain of 2.5 dBi, and a maximum efficiency of 64%. Simultaneously, the multi-band patch antenna 100 has a coverage range of 1.973 GHz to 1.993 GHz in the L band, with a bandwidth of 20 MHz, a relative bandwidth of 1.0%, a maximum gain of 5.5 dBi, and a maximum efficiency of 58%. Furthermore, the multi-band patch antenna 100 has a coverage range of 2.176 GHz to 2.210 GHz in the S band, with a bandwidth of 34 MHz, a relative bandwidth of 1.5%, a maximum gain of 6.4 dBi, and a maximum efficiency of 65%. Under the condition of a 125 mm × 68 mm metal ground plane 10, the dimensional coordination of the aforementioned components ensures stable radiation performance of the multi-band patch antenna 100, and all indicators highly match the design goals. By coordinating the geometric relationship between the radiator 30 and the feed structure 40, and combining the specific specifications of the first capacitive structure 50, the second capacitive structure 70, and the short-circuit parasitic element 60, the dimensional parameters effectively modulate the resonant characteristics of different frequency bands. The radiating slot 3001 and the second short-circuit post 80 work together to further optimize the high-frequency current distribution, thereby achieving multi-frequency coverage of the UHF, L, and S bands within a limited space, verifying the feasibility and effectiveness of this dimensional design in the application of the multi-band patch antenna 100.

[0052] The present invention also proposes a communication device, which includes a multi-band patch antenna 100. The specific structure of the multi-band patch antenna 100 is as described in the above embodiments. Since the communication device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0053] The above are merely exemplary embodiments of the present invention and do not limit the scope of the patent of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A multi-band patch antenna, characterized in that, include: Metal flooring; A dielectric substrate is disposed on one side of the metal ground plane along the z-direction; A radiator is disposed on the side of the dielectric substrate away from the metal floor along the z-direction; A power feeding structure is disposed between the radiator and the dielectric substrate; A first capacitive structure is disposed between the radiator and the dielectric substrate, and located on one side of the feed structure along the x-direction. The first capacitive structure and the feed structure are arranged side by side along the x-direction. The first capacitive structure and the metal ground plane are separated by the dielectric substrate. The first capacitive structure is used to reduce the frequency of the main mode resonant mode of the multi-band patch antenna to the first frequency band. A short-circuit parasitic unit is disposed on one side of the radiator along the y-direction, and the side of the short-circuit parasitic unit closest to the metal floor is electrically connected to the metal floor through a first short-circuit post; A second capacitive structure is provided at one end of the short-circuit parasitic unit along the y-direction and away from the feeding structure, for increasing the bandwidth of the multi-band patch antenna in the first frequency band; Multiple second short-circuit posts are arranged in at least one row along the y-direction of the radiator and disposed between the feed structure and the radiator, for connecting the feed structure and the radiator in the second and third frequency bands, so as to couple radio frequency energy from the feed structure to the radiator to excite higher-order mode resonant modes in the second and third frequency bands; wherein the first frequency band is smaller than the second frequency band, and the second frequency band is smaller than the third frequency band.

2. The multi-band patch antenna as described in claim 1, characterized in that, The multi-band patch antenna is a quarter-wavelength short-circuit patch antenna; The sum of the widths of the radiator and the short-circuit parasitic unit in the y-direction is 40 mm; The length of both the radiator and the short-circuit parasitic unit in the x-direction is 40 mm.

3. The multi-band patch antenna as described in claim 1, characterized in that, The first resilient structure is a first rectangular metal sheet; The first rectangular metal sheet is arranged parallel to the metal floor. By increasing the area of ​​the first rectangular metal sheet or decreasing the distance between the first rectangular metal sheet and the metal ground, the frequency of the master mode resonant mode can be reduced to the first frequency band.

4. The multi-band patch antenna as described in claim 3, characterized in that, The second capacitive structure is a second rectangular metal sheet; The second rectangular metal sheet is arranged parallel to the metal floor. The first frequency band has a first resonant point and a second resonant point; By adjusting the length of the first rectangular metal sheet and the width of the second rectangular metal sheet respectively, the positions of the first resonant point and the second resonant point are controlled, so that the first resonant point and the second resonant point are close to each other and coupled to each other, thereby increasing the bandwidth of the first frequency band.

5. The multi-band patch antenna as described in claim 1, characterized in that, Multiple second short-circuit posts are arranged in two rows along the y-direction of the radiator; The two rows of the second short-circuit posts are staggered along the x-direction of the power supply structure.

6. The multi-band patch antenna as described in claim 5, characterized in that, The two rows of the second short-circuit posts are respectively arranged on both sides of the feed structure along the x-direction.

7. The multi-band patch antenna as described in claim 6, characterized in that, The second short-circuit posts in each row are spaced at equal intervals, with a 1mm interval between two adjacent second short-circuit posts.

8. The multi-band patch antenna as described in claim 6, characterized in that, The radiator is provided with a radiation slot, which extends along the x-direction of the radiator and is correspondingly arranged with the feeding structure. The radiation slot is located between the two rows of second short-circuit posts and is used to regulate the higher-order mode resonance modes of the second frequency band and the third frequency band.

9. The multi-band patch antenna as described in any one of claims 1 to 8, characterized in that, The dielectric substrate includes a first dielectric layer and a second dielectric layer, wherein the first dielectric layer and the second dielectric layer are stacked along the z-direction; And / or, the area of ​​the dielectric substrate is smaller than the area of ​​the metal floor.

10. A communication device, characterized in that, Includes a multi-band patch antenna as described in any one of claims 1 to 9.

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