A high-gain small circularly polarized monopole array antenna and a design method thereof

Abstract

The application discloses a high-gain small-sized circularly polarized monopole array antenna and a design method thereof, and relates to the technical field of antenna design. The antenna comprises a middle dielectric layer, a first L-shaped metal radiation patch, a second L-shaped metal radiation patch, an equal-amplitude power divider, a bottom metal ground, a metal via, a metal tin block, a coaxial line and a plastic support column. The application can simultaneously realize the performance optimization of miniaturization, array high gain, wideband circular polarization, high radiation efficiency and the like. The application can be widely applied to the technical field of antenna design.

Description

Technical Field

[0001] This invention relates to the field of antenna design technology, and in particular to a high-gain, small-sized circularly polarized monopole array antenna and its design method. Background Technology

[0002] Wireless remote control technology is now widely used, and the 2.4GHz industrial, scientific, and medical unlicensed frequency band, with its advantages of global universality and no need for spectrum approval, is widely used in various types of waterborne remote control equipment. These devices have stringent standards for the stability of the wireless control link, anti-interference capabilities, and effective control radius. As the core component of radio frequency transceivers, the antenna's performance directly determines the equipment's maximum operating distance, signal transmission stability, and safety during waterborne operations.

[0003] Conventional linearly polarized monopole radiating antennas offer advantages such as simple construction and low production cost. However, when used in actual waterborne scenarios, they are prone to polarization mismatch at the transmitting and receiving ends due to multipath interference caused by the attitude deviation of the controlled vessel and electromagnetic wave reflection from the water surface. This leads to drastic fluctuations in the received signal amplitude and insufficient stability of the wireless control link. In contrast, circularly polarized antennas can effectively reduce signal fading caused by multipath reflection, alleviate signal loss caused by polarization mismatch, and significantly enhance the anti-interference capability and environmental adaptability of the remote control communication link, making them more suitable for the complex application scenarios of outdoor waterborne remote control. Existing technologies have proposed miniaturized circularly polarized monopole antennas suitable for this type of remote control equipment, which can achieve basic impedance matching and circularly polarized radiation in the 2.40–2.48 GHz frequency band, adapting to the limited installation space inside the remote control. However, the aforementioned single-element circularly polarized antennas still have inherent performance limitations: the antenna gain upper limit of a single radiating element is relatively low, and current commercial equipment equipped with this type of antenna can only achieve a remote control distance of several hundred meters, which is insufficient to meet the needs of users for long-distance waterborne operations. Meanwhile, when the antenna is integrated inside the remote control, the surrounding circuit boards, batteries, metal brackets and other components will significantly affect the antenna's radiation characteristics and impedance matching, further reducing the actual radiation gain and causing a significant reduction in the effective remote control distance.

[0004] To improve antenna radiation gain, the industry standard is to use multi-element antenna arrays, which achieve gain enhancement by superimposing the electromagnetic waves radiated by each element in phase. However, existing circularly polarized array solutions have many drawbacks: most array structures are too large to fit the compact layout inside the remote controller; the array feed network is difficult to achieve equal energy distribution between the two paths, and inconsistent input power between the two radiating elements will weaken the array superposition gain; discrete feed components and multiple independent coaxial cables will occupy additional internal space, and metal feed lines will exacerbate electromagnetic interference inside the fuselage and worsen the antenna radiation environment, making it impossible to simultaneously meet the multiple constraints of miniaturization, equal amplitude and in-phase feeding, high gain, and compatibility with the fuselage's metal components. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a high-gain miniature circularly polarized monopole array antenna and its design method, which can simultaneously achieve multiple performance optimizations including miniaturization, high array gain, wideband circular polarization, and high radiation efficiency.

[0006] The first technical solution adopted in this invention is: a high-gain, small circularly polarized monopole array antenna, comprising an intermediate dielectric layer, a first L-shaped metal radiating patch, a second L-shaped metal radiating patch, an equal-amplitude power divider, a bottom metal ground plane, metal vias, a metal ingot, a coaxial cable, and a plastic support post. The first L-shaped metal radiating patch, the second L-shaped metal radiating patch, and the equal-amplitude power divider are printed on the upper surface of the intermediate dielectric layer. The bottom metal ground plane is printed on the lower surface of the intermediate dielectric layer. The metal vias penetrate the intermediate dielectric layer. The coaxial cable is soldered to the equal-amplitude power divider through the metal ingot. The coaxial cable is electrically connected to the bottom metal ground plane through the metal vias. The plastic support post is installed on the side of the intermediate dielectric layer, wherein: The intermediate dielectric layer is used to support the radiating structure and the grounding structure, providing physical support and electromagnetic isolation. The radiating structure includes a first L-shaped metal radiating patch, a second L-shaped metal radiating patch, and an equal amplitude power divider. The grounding structure includes a bottom metal ground. The first L-shaped metal radiating patch and the second L-shaped metal radiating patch serve as the array dual-radiating body. The unit is miniaturized by extending the equivalent current path through bending branches, and orthogonal electric field components are formed to excite circularly polarized electromagnetic waves. The equal-amplitude power divider is used to evenly distribute the input radio frequency energy, and to deliver excitation signals with consistent amplitude and synchronized phase to the first L-shaped metal radiating patch and the second L-shaped metal radiating patch. The bottom metal ground is used to adjust the current distribution of the first L-shaped metal radiating patch and the second L-shaped metal radiating patch respectively, and to correct the phase deviation of the orthogonal electric field. The metal via is used to connect the inner conductor of the coaxial cable to the bottom metal ground to form a power supply grounding loop; The tin block is used to achieve a stable weld between the inner conductor of the coaxial cable and the equal-amplitude power divider, ensuring stable transmission of the radio frequency excitation signal; The coaxial cable includes an inner conductor and an outer conductor, and the coaxial cable is used to feed radio frequency excitation signals to the antenna. The plastic support column is used to fix the intermediate medium layer.

[0007] Furthermore, the first L-shaped metal radiating patch and the second L-shaped metal radiating patch are symmetrically arranged on the upper surface of the dielectric substrate. Both the first L-shaped metal radiating patch and the second L-shaped metal radiating patch include an integrally bent horizontal radiating arm and a vertical radiating arm, wherein: The horizontal and vertical radiation arms are used to form two mutually perpendicular current radiation paths, which generate orthogonal electric field components with a 90° phase difference after feeding, thus exciting the circularly polarized radiation mode. The integrally bent structure is used to extend the equivalent current radiation path, thereby miniaturizing the radiation unit without increasing the substrate size.

[0008] Furthermore, the bottom metal ground includes a first grounding metal surface and a second grounding metal surface, which are integrally connected to form a complete reference ground plane. The edge contours of the first grounding metal surface and the second grounding metal surface have differentiated edge structures, wherein: The first grounding metal surface and the second grounding metal surface are used to form a coupling resonant structure with the first L-shaped metal radiating patch and the second L-shaped metal radiating patch on the corresponding side, respectively, so as to independently adjust the input impedance of the two current radiation paths. The differentiated edge structure is used to disturb the induced current under the first L-shaped metal radiating patch and the second L-shaped metal radiating patch respectively, regulate the phase difference of the orthogonal polarization components, and reduce the electromagnetic mutual coupling between units. The integrated, interconnected reference ground plane is used to provide a complete grounding loop and suppress antenna back radiation.

[0009] Furthermore, the equal-amplitude power divider is disposed between the first L-shaped metal radiating patch and the second L-shaped metal radiating patch, and adopts an integrated wiring structure with single-ended input and two symmetrical outputs, wherein: The single-ended input is used to connect to the inner conductor of the coaxial cable and receive external radio frequency excitation signals; The two symmetrical outputs are used to connect the first L-shaped metal radiating patch and the second L-shaped metal radiating patch respectively, so as to achieve equal output signal amplitude and phase synchronization.

[0010] Furthermore, a grounding metal patch is provided on the upper surface of the intermediate dielectric layer. The grounding metal patch is connected to the bottom metal ground through a metal via. The outer conductor of the coaxial cable is welded to the grounding metal patch, and electrical grounding with the bottom metal ground is achieved through the metal via.

[0011] Furthermore, the intermediate dielectric layer is a single-layer planar dielectric substrate without multi-layer dielectric stacking or three-dimensional parasitic metal components, and the cross-sectional height of the intermediate dielectric layer is equal to the substrate thickness.

[0012] Furthermore, the inner conductor of the coaxial cable is an RF coaxial line, and it adopts a side-mounted single-point feeding layout, eliminating the need for external discrete power distribution components and phase-shifting networks.

[0013] The second technical solution adopted in this invention is: a design method for a high-gain, small-scale circularly polarized monopole array antenna, comprising: Determine the circular polarization and gain performance indicators of the array antenna, construct two sets of symmetrically arranged L-shaped radiating patches and an integrated equal amplitude power distribution line to form the upper radiating layer structure; Design a bottom metal grounding structure with differentiated profiles, independently control the surface current distribution of two sets of L-shaped radiating patches, broaden the impedance and axial ratio working bandwidth, and construct the bottom grounding layer structure. A side coaxial power supply component is introduced, and the inner conductor of the coaxial cable is connected to the input end of the equal amplitude power divider through a metal tin block. A power supply grounding loop is constructed with metal vias. The upper radiating layer, single-layer dielectric substrate, and feed grounding circuit are assembled and fixed to obtain a high-gain small circularly polarized monopole array antenna.

[0014] The beneficial effects of the antenna and design method of this invention are as follows: This invention adopts a single-layer dielectric substrate planar architecture, with a differentiated segmented extended metal grounding structure set on the back of the substrate, and two sets of symmetrical bent orthogonal L-shaped monopole radiating patches on the front of the substrate. An integrated equal-amplitude power divider is integrated in the middle to achieve single-path coaxial equal-division feeding. By applying boundary perturbations to the two sets of radiated electric fields through differentiated stepped grounding branches, the resonant frequency and phase difference of the two sets of orthogonal radiation modes are independently controlled, realizing efficient coupling of dual-unit orthogonal degenerate modes. Simultaneously, multiple performance optimizations are achieved, including miniaturization, high array gain, wideband circular polarization, and high radiation efficiency. Moreover, without introducing multi-layer dielectric interfaces and complex discrete shift matching networks, the dielectric loss and reflection loss during electromagnetic signal transmission are greatly reduced. The equal-amplitude and in-phase superposition of the dual radiating units further improves the peak gain of the array. Attached Figure Description

[0015] Figure 1 This is a top view of a high-gain, small circularly polarized monopole array antenna according to the present invention; Figure 2 This is a flowchart of a design method for a high-gain, small circularly polarized monopole array antenna according to the present invention; Figure 3 This is a top view of the antenna bottom provided in a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the left side view of the antenna provided in a specific embodiment of the present invention; Figure 5 This is a schematic diagram of the right side view of the antenna provided in a specific embodiment of the present invention; Figure 6This is a schematic diagram of the first structural surface of antenna A provided in a specific embodiment of the present invention; Figure 7 This is a schematic diagram of the second structural surface of antenna A provided in a specific embodiment of the present invention; Figure 8 This is a schematic diagram of the first structural surface of antenna B provided in a specific embodiment of the present invention; Figure 9 This is a schematic diagram of the second structural surface of antenna B provided in a specific embodiment of the present invention; Figure 10 This is a schematic diagram of antenna A, antenna B, and the simulation coefficients of the antenna provided in a specific embodiment of the present invention; Figure 11 This is a schematic diagram of the simulated axial ratio of antenna A, antenna B, and antenna provided in a specific embodiment of the present invention; Figure 12 This is a schematic diagram of the simulation coefficients of the antenna provided in a specific embodiment of the present invention; Figure 13 This is a schematic diagram of the axial ratio of the antenna simulation provided in a specific embodiment of the present invention; Figure 14 This is a gain diagram of antenna simulation provided in a specific embodiment of the present invention; Figure 15 This is a schematic diagram of the first structural surface of a single monopole antenna provided in a specific embodiment of the present invention; Figure 16 This is a schematic diagram of the second structural surface of a single monopole antenna provided in a specific embodiment of the present invention; Figure 17 This is a schematic diagram comparing the gain of an antenna array and a single monopole antenna according to a specific embodiment of the present invention.

[0016] Reference numerals: 1. First L-shaped metal radiating patch; 2. Second L-shaped metal radiating patch; 3. Equal amplitude power divider; 4. Metal tin block; 5. Inner conductor of coaxial cable; 6. Metal via; 7. Outer conductor of coaxial cable; 8. First grounding metal surface; 9. Second grounding metal surface; 10. Intermediate dielectric layer; 11. Plastic support column; 12. Insulating dielectric layer of coaxial cable. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

[0018] First, existing technologies have the following problems, for example: 1) Existing antennas, for example, have proposed a three-layer dielectric broadband dipole circularly polarized antenna that can achieve a wide circular polarization bandwidth. However, this antenna adopts a complex layered architecture with multiple dielectric layers and support pillars, which makes the processing and assembly process cumbersome and costly. The overall size is relatively large, and miniaturization and integration are difficult. Moreover, it is only a single radiating element, and the antenna gain is limited, which cannot meet the requirements of long-distance remote control operation. The ultra-wide bandwidth has performance redundancy in the 2.4~2.48GHz narrowband scenario.

[0019] 2) Existing examples include single-layer metasurface low-profile circularly polarized antennas, which can slightly improve antenna gain. However, these rely on precision metasurface arrays, are sensitive to manufacturing tolerances, and do not match the 2.4GHz ISM band. They lack an integrated equal-amplitude power-dividing array design, making it impossible to further increase gain through in-phase stacking of dual units. Furthermore, the lack of differentiated optimization of the dual-unit grounding structure leads to severe mutual coupling between array units, resulting in degraded internal impedance and axial ratio performance. In addition, existing circularly polarized antennas adapted for maritime remote control are mostly single-unit structures with low gain and limited remote control distance. Conventional dual-unit arrays are either multi-layered and bulky, or have uneven feeding and unoptimized grounding symmetry, failing to achieve high array gain, a small and thin profile, and excellent circular polarization characteristics in the 2.4GHz band within a compact substrate. Therefore, existing circularly polarized antennas struggle to simultaneously meet the multiple requirements of a simple single-layer structure, high array gain, miniaturized integration, and precise adaptation to the 2.4~2.48GHz remote control band. Related technologies require further improvement and refinement.

[0020] Based on this, the present invention improves upon the single-element circularly polarized monopole antenna by designing a dual-element circularly polarized array antenna. The power divider provides coaxial equal-amplitude feeding to ensure balanced input energy for the two radiating elements. The array superposition enhances the overall radiation gain while maintaining a compact size and adapting to the complex metallic electromagnetic environment inside the remote controller. This has significant practical and engineering value for extending the effective operating distance of the equipment, improving the reliability of the remote control link, and reducing the difficulty of equipment integration.

[0021] This invention comprises only three layers: a metal radiating patch, an intermediate dielectric layer, and a bottom metal ground plane. Its structure is extremely simple and compact, facilitating device integration. It accurately covers the 2.4GHz~2.48GHz ISM narrowband frequency band, with a full-band reflection coefficient S11 below -6dB and no redundant frequency band performance. The left-hand circularly polarized 3D radiation peak gain can reach 3.0dBic, offering superior gain performance compared to a single simple monopole antenna. It exhibits uniform radiation throughout space, with gain dips only at extremely small angles, demonstrating excellent omnidirectional radiation characteristics. It boasts good inner-band axial ratio purity and stable circularly polarized radiation performance. The overall design eliminates complex components such as multi-layer stacking, metal support pillars, and multi-feed networks, resulting in fewer processing and assembly steps and lower production costs.

[0022] Reference Figure 1This invention provides a high-gain, small-sized circularly polarized monopole array antenna. The antenna includes an intermediate dielectric layer 10, a first L-shaped metal radiating patch 1, a second L-shaped metal radiating patch 2, an equal-amplitude power divider 3, a bottom metal ground plane, a metal via 6, a metal ingot 4, a coaxial cable, and a plastic support post 11. The first L-shaped metal radiating patch, the second L-shaped metal radiating patch, and the equal-amplitude power divider are printed on the upper surface of the intermediate dielectric layer. The bottom metal ground plane is printed on the lower surface of the intermediate dielectric layer. The metal via penetrates the intermediate dielectric layer. The coaxial cable is soldered to the equal-amplitude power divider through the metal ingot. The coaxial cable is electrically connected to the bottom metal ground plane through the metal via. The plastic support post is mounted on the side of the intermediate dielectric layer. The intermediate dielectric layer is used to support the radiating structure and the grounding structure, providing physical support and electromagnetic isolation. The radiating structure includes a first L-shaped metal radiating patch, a second L-shaped metal radiating patch, and an equal amplitude power divider. The grounding structure includes a bottom metal ground. Specifically, a grounding metal patch is also provided on the upper surface of the intermediate dielectric layer. The grounding metal patch is connected to the bottom metal ground through a metal via. The outer conductor of the coaxial cable is welded to the grounding metal patch and electrically grounded to the bottom metal ground through the metal via. The intermediate dielectric layer is a single-layer planar dielectric substrate without multi-layer dielectric stacking or three-dimensional parasitic metal components. The cross-sectional height of the intermediate dielectric layer is equal to the substrate thickness.

[0023] The first L-shaped metal radiating patch and the second L-shaped metal radiating patch serve as the array dual-radiating body. The unit is miniaturized by extending the equivalent current path through bending branches, and orthogonal electric field components are formed to excite circularly polarized electromagnetic waves. Specifically, the first L-shaped metal radiating patch and the second L-shaped metal radiating patch are symmetrically arranged on the upper surface of the dielectric substrate. Both the first L-shaped metal radiating patch and the second L-shaped metal radiating patch include an integrally bent horizontal radiating arm and a vertical radiating arm. The horizontal radiating arm and the vertical radiating arm are used to form two mutually perpendicular current radiation paths. After being fed, they generate orthogonal electric field components with a 90° phase difference, which excite the circularly polarized radiation mode. The integrally bent structure is used to extend the equivalent current radiation path, thereby miniaturizing the radiating unit without increasing the substrate size.

[0024] The equal-amplitude power divider is used to evenly distribute the input radio frequency energy, and to deliver excitation signals with consistent amplitude and synchronized phase to the first L-shaped metal radiating patch and the second L-shaped metal radiating patch. Specifically, the equal-amplitude power divider is disposed between the first L-shaped metal radiating patch and the second L-shaped metal radiating patch, and adopts an integrated wiring structure with single-ended input and two symmetrical outputs. The single-ended input is used to connect to the inner conductor of the coaxial cable to receive external radio frequency excitation signals; the two symmetrical outputs are used to connect the first L-shaped metal radiating patch and the second L-shaped metal radiating patch respectively to achieve equal amplitude and phase synchronization of the output signals.

[0025] The bottom metal ground is used to adjust the current distribution of the first L-shaped metal radiating patch and the second L-shaped metal radiating patch respectively, and to correct the phase deviation of the orthogonal electric field. Specifically, the bottom metal ground plane includes a first grounding metal surface 8 and a second grounding metal surface 9. The first grounding metal surface and the second grounding metal surface are integrally connected to form a complete reference ground plane. The edge contours of the first grounding metal surface and the second grounding metal surface have differentiated edge structures. The first grounding metal surface and the second grounding metal surface are used to form a coupling resonance structure with the first L-shaped metal radiating patch and the second L-shaped metal radiating patch on the corresponding side, respectively, to independently control the input impedance of the two current radiation paths. The differentiated edge structure is used to disturb the induced current under the first L-shaped metal radiating patch and the second L-shaped metal radiating patch, respectively, to control the phase difference of the orthogonal polarization components and reduce the electromagnetic mutual coupling between units. The integrally connected reference ground plane is used to provide a complete grounding loop and suppress the rearward radiation of the antenna.

[0026] The metal via is used to connect the inner conductor of the coaxial cable to the bottom metal ground to form a power supply grounding loop; The tin block is used to achieve a stable weld between the inner conductor of the coaxial cable and the equal-amplitude power divider, ensuring stable transmission of the radio frequency excitation signal; The coaxial cable includes an inner conductor 5 and an outer conductor 7 of the coaxial cable, and the coaxial cable is used to feed radio frequency excitation signals to the antenna. Specifically, the inner conductor of the coaxial cable is an RF coaxial line, which adopts a side-mounted single-point power supply layout and does not require external discrete power distribution devices and phase shifting networks.

[0027] The plastic support column is used to fix the intermediate medium layer.

[0028] In summary, as Figure 1As shown, the present invention has a square layout and continues the overall architecture of three-layer planar stacking. It mainly consists of two sets of symmetrically arranged upper L-shaped metal radiating patches, a middle dielectric layer, a bottom metal ground, and a coaxial single-ended feeding structure integrating an equal amplitude power divider network. The two sets of L-shaped metal radiating patches are array dual-radiating bodies. They achieve unit miniaturization by extending the equivalent current path through their own bent branches. A 90° phase difference is formed by two orthogonal branches to excite and generate circularly polarized electromagnetic waves. The equal-amplitude power divider is used to evenly distribute the input RF energy, delivering excitation signals with consistent amplitude and synchronized phase to the two sets of radiating patches, and improving the overall radiation gain of the array by relying on the in-phase superposition of electromagnetic waves; the metal tin block is used to achieve a stable welding connection between the inner conductor of the coaxial cable and the equal-amplitude power divider, preventing open circuits at the feed node and stabilizing the transmission of RF excitation signals; the inner conductor of the coaxial cable is used to feed RF electrical signals to the equal-amplitude power divider; the intermediate dielectric layer is used to support the two sets of L-shaped metal radiating patches, provide physical support and electromagnetic isolation, and help optimize the impedance characteristics of the entire 2.4GHz~2.48GHz frequency band; the plastic support column is used to fix the antenna substrate as a whole, adapting to the narrow installation space inside the equipment. Two sets of L-shaped metal radiating patches form the dual-radiating body of the array. Their respective bending structures can extend the equivalent current radiation path without increasing the overall area occupied by the substrate, thus achieving miniaturization of a single antenna element. Each L-shaped structure has two mutually perpendicular horizontal and vertical stubs. After feeding, the currents of the two branches can form a 90° phase difference. Two circularly polarized electromagnetic waves can be excited by relying only on the back-end power divider network and a single coaxial feed, without the need for an additional phase-shifting network, which can ensure the excellent axial ratio purity of the array as a whole. By optimizing the length ratio of the two L-shaped stubs, the impedance index of the 2.4GHz~2.48GHz operating frequency band can be accurately matched, so that the S11 parameter in the operating frequency band is below -6dB. The cooperative radiation of the orthogonal stubs can also balance the spatial radiation level and weaken the radiation dip. The equal-amplitude power divider adopts an integrated wiring structure to achieve equal distribution of the two output energy, ensuring that the RF signals flowing to the radiating patch have consistent amplitude and phase synchronization. It relies on the in-phase superposition of electromagnetic waves from the array unit to improve the overall radiation gain. The antenna as a whole adopts a single-ended coaxial cable for centralized feeding. The inner conductor of the coaxial cable is stably soldered to the power divider through a metal tin block to avoid open circuit faults at the feeding connection. It reliably inputs RF excitation signals to the power divider network, completing port impedance matching and equal transmission of the two signals.The intermediate dielectric layer is placed between the two sets of metal radiating patches and the bottom metal ground plane, serving the dual functions of physical support and electromagnetic isolation, and helping to optimize the impedance characteristics of the entire 2.4GHz~2.48GHz frequency band. The outer conductor of the coaxial cable is connected to the bottom metal ground plane by metal patches and four metal vias, forming a complete and reliable feed grounding loop, which greatly reduces the RF loss of the feed link and ensures that the two radiating elements receive a stable and consistent excitation input. The plastic support helps to fix the antenna. Under the compact substrate layout, it takes into account the multiple advantages of high array gain, stable unit circular polarization performance, simple and reliable feed structure, and adaptability to the small installation space inside the equipment.

[0029] like Figure 3 As shown, the differentiated metal ground at the bottom is used to regulate the current distribution of the two sets of radiating units, correct the phase deviation of the orthogonal electric field, and suppress the mutual coupling of the units. The bottom metal ground planes corresponding to the two sets of radiating units are integrated and connected to form a complete reference ground plane for the array. This can simultaneously improve the overall spatial radiation uniformity of the dual units, suppress back radiation of the array, and reduce useless radiation loss. The two sets of metal ground planes form independent coupled resonant structures with the corresponding L-shaped monopole radiating patches on the upper layer, which can precisely control the input impedance of the two radiating branches in the 2.4~2.48GHz frequency band, and synergistically optimize the in-band S11 matching effect of the entire array. Each metal ground plane can balance the electromagnetic radiation intensity of the two orthogonal paths of the corresponding L-shaped branches, correct the phase deviation between the orthogonal electric fields, and simultaneously ensure the circular polarization purity of the two radiating units, avoiding mutual interference of polarization performance between array units. At the same time, the integrated and connected metal ground planes provide a complete grounding loop for the front-end coaxial feed structure. With the help of the bottom metal vias, the feed outer conductor is reliably grounded, which greatly reduces the RF loss of the power divider feed network and ensures that the amplitude and phase of the excitation signals of the two radiating units are highly consistent. Ultimately, the array achieves a comprehensive effect of in-phase superposition gain improvement, stable unit circular polarization performance, and excellent in-band impedance matching.

[0030] Furthermore, such as Figure 4 as well as Figure 5As shown, metal vias connect the coaxial outer conductor to the bottom metal ground plane, forming a complete grounding loop. The outer conductor of the coaxial cable connects to the metal patch, working with the metal vias to complete the feed grounding. The inner conductor of the coaxial cable is reliably connected to the equal-amplitude power divider via a metal solder block. The outer conductor of the coaxial cable is reliably soldered to the bottom metal ground plane and bottom metal surface via a metal layer, forming a stable impedance-matched feed path adapted to the 2.4GHz ISM band. Regarding the feed structure, a single-ended coaxial feed directly excites the radiating patch, eliminating the need for additional microstrip matching stubs and complex phase-shifting networks. This results in a simple structure, low RF transmission loss, and easy integration with RF circuits in small devices. A single-layer dielectric substrate is sandwiched between the upper radiating patch and the bottom metal ground plane, providing physical support for the radiating element. This ensures low dielectric loss and stable signal transmission in the microwave band while achieving a low-profile antenna design, adapting to the application requirements of miniaturized and highly integrated terminals. The side view structure intuitively demonstrates the core technical features of this invention: single-layer dielectric, no multi-layer stacking, no additional auxiliary structures such as metal support columns, low profile, and easy processing and integration. Relying on the coupling effect between the L-shaped monopole radiating unit and the metal ground, it provides reliable structural support for efficient transmission of feed signals, target narrowband impedance matching, and stable circular polarization radiation. In addition, a coaxial cable insulating dielectric layer 12 is provided around the inner conductor of the coaxial cable.

[0031] like Figure 6 as well as Figure 7 The image shows the initial ground metal layer of the antenna (antenna A). The high-gain, wideband circular polarization performance parameters of the 2.4-2.48 GHz array antenna were determined. Two sets of symmetrically arranged L-shaped radiating patches and an integrated equal-amplitude power distribution line were constructed to form the upper radiating layer structure. Two sets of mirror-symmetrical, perfectly contoured bottom metal grounding layers were designed to match the dual-element symmetrical layout. The surface induced current of the radiating elements was initially controlled to construct the bottom grounding metal layer structure. A side-mounted single-point coaxial feed assembly was introduced, connecting the coaxial inner conductor and the power divider input terminal through a metal tin block, and a complete grounding loop was constructed using metal vias. The upper radiating layer, single-layer dielectric substrate, and bottom symmetrical metal ground layer were assembled and fixed to obtain a symmetrically grounded dual-element circularly polarized array antenna. Figure 10 As shown, antenna A has near-zero impedance matching in the 2.4GHz-2.48GHz frequency band, resulting in a bandwidth mismatch. Meanwhile, as... Figure 12 As shown, antenna B does not meet the 3 dB axial ratio requirement in the 2.4 GHz-2.48 GHz frequency band, and its circular polarization performance is extremely poor, which cannot meet the requirements of broadband circular polarization applications.

[0032] like Figure 8 as well as Figure 9As shown, based on the structure of antenna A, two sets of bottom-layer metal grounding profiles are designed differently, and the surface induced current of the two sets of radiating elements is independently controlled to broaden the impedance and axial ratio operating bandwidth, constructing a bottom-layer grounding metal layer structure, and further improving antenna B. Compared to the metal ground structure of antenna A, the metal ground structure of antenna B has been finely adjusted and differs from structure A. For example... Figure 10 As shown, antenna B can meet the -6 dB impedance matching requirement in the 2.4GHz-2.48GHz frequency band. Meanwhile, as... Figure 11 As shown, antenna B still meets the 3 dB axial ratio requirement in the 2.4 GHz-2.47 GHz frequency band, but still cannot meet the application requirements of broadband circular polarization in the 2.4 GHz-2.48 GHz band.

[0033] To address the technical issue of insufficient circular polarization bandwidth in the aforementioned antennas, further differentiated optimization of the two grounded metal surfaces was implemented based on antenna B. The protruding portions of the metal ground structure were removed, resulting in the final optimized antenna. By leveraging the differentiated edge structures of the two metal ground surfaces to create different load effects, the surface current distribution of the two sets of L-shaped radiating elements was finely controlled, reducing inter-element mutual coupling interference and simultaneously smoothing the fluctuations in the impedance and axial ratio curves. This achieved a synergistic widening and optimization of both impedance bandwidth and circular polarization axial ratio bandwidth. Figure 10 As shown, the final antenna achieves continuous and stable -6dB impedance matching in the approximately 2.4-2.48 GHz frequency band. Its broadband impedance matching performance is significantly superior to the previous two structures, exhibiting a large resonance depth and stable matching without significant fluctuations. Meanwhile, as... Figure 11 As shown, the final antenna achieves an axial ratio of less than 3dB across the entire 2.4-2.5GHz frequency band, exhibiting continuous, stable, and flat circular polarization performance. Its overall circular polarization performance is significantly superior to antennas A and B, effectively suppressing multipath interference and polarization mismatch loss. It is suitable for broadband circular polarization applications in multi-band wireless communication systems.

[0034] Reference Figure 2 A design method for a high-gain, small-scale circularly polarized monopole array antenna, comprising: S100. Determine the circular polarization and gain performance indicators of the array antenna, construct two sets of symmetrically arranged L-shaped radiating patches and an integrated equal amplitude power distribution line to form the upper radiating layer structure. S200, with a bottom metal grounding structure featuring a differentiated profile, independently controls the surface current distribution of two sets of L-shaped radiating patches, broadens the impedance and axial ratio working bandwidth, and constructs the bottom grounding layer structure; S300 introduces a side coaxial power supply component, which connects the inner conductor of the coaxial cable to the input end of the equal amplitude power divider through a metal tin block, and constructs a power supply grounding loop with metal vias. S400: Assemble and fix the upper radiating layer, single-layer dielectric substrate, and feed grounding circuit to obtain a high-gain small circularly polarized monopole array antenna.

[0035] Finally, with reference to the accompanying drawings, the performance indicators of the optimized antenna according to the embodiment of the present invention will be described in detail: like Figure 12 As shown in the figure, the horizontal axis represents the operating frequency, ranging from 2.38 GHz to 2.5 GHz, and the vertical axis represents the reflection coefficient S11, in dB. In engineering, -10 dB is typically used as the impedance matching threshold standard. However, this invention targets the 2.4 GHz ISM narrowband communication scenario, using S11 ≤ -6 dB as the effective operating criterion. As shown in the figure, the antenna of this invention achieves a reflection coefficient S11 below -6 dB across the entire operating frequency band from 2.4 GHz to 2.48 GHz, realizing excellent broadband impedance matching. A deep resonant point is formed near 2.45 GHz, with a minimum return loss of approximately -15 dB. Furthermore, the entire frequency band curve exhibits smooth fluctuations without obvious sharp dips. The coaxial single-ended feed structure achieves optimal matching through the synergistic optimization of the equal-amplitude power divider, two sets of L-shaped monopole radiating patches, and two corresponding bottom metal ground planes with metal protrusions.

[0036] like Figure 13 As shown in the figure, the horizontal axis represents the operating frequency, and the vertical axis represents the axial ratio, both in dB. The 3 dB dashed line represents the engineering threshold for circular polarization radiation. The figure shows that the antenna's axial ratio is below 3 dB in the 2.4 GHz to 2.48 GHz frequency band, achieving excellent broadband circular polarization radiation characteristics. This indicates that by loading two sets of L-shaped monopole radiating patches and their corresponding two sets of metal ground structures, the current distribution on the antenna surface is effectively controlled, generating orthogonal and equal-amplitude field components, ensuring stable circular polarization performance over a wide frequency range, and effectively suppressing multipath interference and polarization loss.

[0037] like Figure 14 As shown in the figure, the horizontal axis represents the operating frequency, and the vertical axis represents the gain, in dB. The figure shows that the antenna gain remains consistently above 4 dBi within the 2.4 GHz to 2.48 GHz operating frequency band, peaking at approximately 6 dBi near the center frequency of this band. It then decreases slightly at higher frequencies but remains above 4 dBi. This stable high-gain characteristic indicates that the antenna possesses excellent signal focusing capability over a wide frequency range, effectively improving the signal coverage and transmission quality of the wireless link.

[0038] like Figure 17 As shown, this invention relates to a dual-element antenna array and a single L-shaped monopole circularly polarized antenna (e.g., Figure 15 and Figure 16The gain comparison curves are shown in the figure. The solid line represents the gain curve of the antenna array of this invention, and the dashed line represents the gain curve of a single monopole antenna. In the target operating frequency band of 2.4~2.48GHz, the array gain is stable at 5.5~6.1dB, while the monopole unit gain is only maintained at 3.5~4.1dB, with the difference between the two remaining stable at about 2dB. This gain improvement originates from the integrated equal-amplitude power divider network delivering radio frequency signals with completely consistent amplitude and phase to the two sets of radiating units. The electromagnetic waves radiated by the two sets of units are superimposed in phase in space, realizing the convergence of directional radiation energy. Under the premise of only a slight increase in the overall size of the substrate, while still maintaining miniaturization and internal integration, the antenna radiation gain is effectively improved.

[0039] In summary, compared with existing technologies, the miniaturized equal-amplitude power-divided dual-element L-shaped monopole circularly polarized array antenna of this invention adopts a single-layer dielectric substrate planar architecture. A differentiated segmented extended metal grounding structure is set on the back of the substrate, combined with two sets of symmetrically bent orthogonal L-shaped monopole radiating patches on the front of the substrate. An integrated equal-amplitude power divider is integrated in the middle to achieve single-path coaxial equal-divided feeding. Differential stepped grounding branches are used to perform boundary perturbations on the two sets of radiated electric fields, independently controlling the resonant frequency and phase difference of the two sets of orthogonal radiation modes, achieving efficient coupling of dual-element orthogonal degenerate modes. This effectively solves the technical problems of insufficient gain in traditional single-element circularly polarized antennas, bulky multi-layer stacking of conventional arrays, and severe mutual coupling of array elements leading to bandwidth and axial ratio degradation. Simultaneously, it achieves multiple performance optimizations including miniaturization, high array gain, wideband circular polarization, and high radiation efficiency. The entire array meets the impedance matching requirement of S11 < −6 dB in the 2.4–2.48 GHz band, and the overall axial ratio is better than 3 in the 2.4–2.48 GHz band. dB ensures stable and balanced circularly polarized radiation within a wide bandwidth, significantly improving the reliability of long-distance communication for maritime remote control equipment. This invention employs an integrated planar structure with a single-layer dielectric substrate, an integrated power divider feed network, a back-side metal ground layer, and a 50Ω coaxial cable single-end feed. The substrate is compact and lightweight. Compared to existing technologies such as multi-layer stacked arrays, three-dimensional dipole antennas, or multi-cable discrete feed arrays, this array solution maintains a very small overall volume and a minimalist planar structure, balancing array gain enhancement with equipment miniaturization and assembly requirements. This not only reduces manufacturing costs and internal assembly difficulty but also perfectly adapts to the complex integration environment of a remote control handle with a small body and densely packed metal components, facilitating conformal integration with terminal RF circuits. Thanks to the single-layer dielectric planar structure and the simple integrated power divider feed path, this invention avoids the introduction of multi-layer dielectric interfaces and complex discrete shift-matching networks, significantly reducing dielectric loss and reflection loss during electromagnetic signal transmission. The equal-amplitude and in-phase superposition of dual radiating elements further enhances the array's peak gain. Furthermore, this invention requires only single-layer metal etching, integrated power distribution lines, and simple coaxial mounting, with low requirements for PCB processing technology. It does not require high-precision bonding or layered assembly processes and has high tolerance for dielectric substrate parameters. While achieving array gain improvement and extending remote control operating distance, it still maintains low mass production process threshold and low manufacturing cost, ensuring product mass production consistency and large-scale engineering application prospects. It perfectly solves the pain points of existing array antennas, such as large size, complex structure, and difficulty in balancing gain improvement and miniaturization.

[0040] Compared with the prior art, the present invention features an overall design of a dual-radiating element circularly polarized array antenna with a single-layer dielectric substrate, two sets of differentiated segmented extended stepped grounding structures, and an integrated equal-amplitude power divider network. Two sets of integrally bent L-shaped monopole radiating patches are symmetrically arranged on the front of the single-layer dielectric substrate. Each patch forms two mutually perpendicular orthogonal radiating arms through integral bending, which can simultaneously excite two orthogonal linearly polarized waves. An integrated, interconnected basic half-amplitude metal grounding layer is laid on the back of the substrate, and multi-stage differentiated stepped grounding branches extend corresponding to the two sets of radiating elements. Combined with a single 50Ω coaxial single-ended total feed layout on the side of the substrate, the feed signal is first input to the integrated equal-amplitude power divider to evenly split into two equal-amplitude, in-phase signals, and then input to the two sets of radiating patches respectively. Finally, the coaxial outer conductor is shorted to the back ground through a grounded metal via array. By relying on the orthogonal radiating arms of two sets of L-shaped radiating patches, each with its corresponding differentiated stepped grounding branches, the two sets of radiated electric fields are subjected to independent boundary perturbations. Single-point total feeding allows the two array elements to form degenerate modes with equal amplitude and a stable 90° phase difference. The electromagnetic waves of the two elements are superimposed in phase to improve the overall radiation gain and simultaneously broaden the impedance bandwidth and axial ratio bandwidth of the array antenna. This solves the technical bottlenecks of insufficient gain of traditional single-element circularly polarized antennas, bulky multi-layer stacking of conventional arrays, and severe mutual coupling of array elements leading to deterioration of impedance and axial ratio bandwidth.

[0041] The invention's primary core protection feature consists of two symmetrically arranged, integrated, bent L-shaped monopolar radiating patches with orthogonal dual radiating arms, along with an integrated equal-amplitude power distribution line in the middle. The integral metal molding achieves two orthogonal polarization branches and equal power transmission, eliminating the need for multiple patches and discrete power components, significantly simplifying PCB manufacturing. Each L-shaped patch's two vertical radiating arms naturally provide orthogonal electric fields, forming the fundamental structure for stable circular polarization radiation. The second core protection feature is the segmented, extended, differentiated, multi-step grounding branches on the back of the substrate corresponding to the two sets of units. This structure can separately disturb the induced current below the two sets of radiating units, finely controlling the phase difference between the two orthogonal polarization components, while simultaneously weakening electromagnetic coupling between array units. This effectively widens the entire array's 3dB axial ratio bandwidth without increasing the overall antenna size and maintaining miniaturization, achieving broadband stable circular polarization. Another distinguishing feature of this embodiment is its small, integrated single-layer planar array structure. The entire structure uses only a single-layer dielectric substrate, without multi-layer dielectric stacking or three-dimensional parasitic metal components. The overall substrate profile is compact and thin, with a cross-sectional height equal to the substrate thickness. This minimalist planar array structure achieves high array gain and extends the remote control operating distance while maintaining the advantages of miniaturization and lightweight design. It significantly reduces the difficulty of PCB etching, assembly, and soldering, and is suitable for the high integration requirements of the small body of the waterborne remote control handle with densely packed metal components inside. This is a core protection feature at the structural level.

[0042] Meanwhile, this invention protects a dedicated side-mounted single-point coaxial main power supply + on-chip integrated power divider power supply structure: only a single main power supply point is set, the coaxial inner core is directly connected to the input terminal of the on-chip equal amplitude power divider, and the coaxial outer conductor is shorted to the back metal ground layer through multiple sets of grounding via arrays; the entire process uses only a single external power supply path, eliminating the need for complex power supply devices such as external discrete power dividers and couplers, significantly reducing the RF loss of the power supply link and achieving excellent impedance matching at the port, which is a core protection point at the power supply structure level. Furthermore, this invention also protects the broadband performance parameters and typical application scenarios corresponding to the antenna array, which constitute the protection content at the performance and application level of this invention: The antenna array is adapted to the 2.4GHz ISM universal unlicensed frequency band, achieving S11 < −6dB impedance matching in the entire 2.4~2.48GHz frequency band, and the axial ratio in the 2.4~2.48GHz range is generally better than 3dB; the peak gain after array superposition is significantly higher than that of a single-element antenna, and the radiation gain is improved by relying on the superposition of dual-element equal-amplitude in-phase arrays. The array gain is stably maintained at 5.5~6.1dB in the target operating frequency band, which is about 1.5dB higher than that of a traditional single-element circularly polarized antenna, effectively extending the remote control operation distance under the same transmission power; the overall structure only adopts a single-layer metal etching process, with high processing tolerance and good mass production consistency, and can be widely used in short-range wireless remote control communication scenarios such as 2.4GHz water remote control equipment and portable wireless control terminals.

[0043] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this is not intended to limit the scope of the embodiments of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the embodiments of the present application.

Claims

1. A high-gain, small-sized circularly polarized monopole array antenna, characterized in that, The system includes an intermediate dielectric layer, a first L-shaped metal radiating patch, a second L-shaped metal radiating patch, an equal-amplitude power divider, a bottom metal ground plane, metal vias, a tin ingot, a coaxial cable, and plastic support pillars. The first L-shaped metal radiating patch, the second L-shaped metal radiating patch, and the equal-amplitude power divider are printed on the upper surface of the intermediate dielectric layer. The bottom metal ground plane is printed on the lower surface of the intermediate dielectric layer. The metal vias penetrate the intermediate dielectric layer. The coaxial cable is soldered to the equal-amplitude power divider through the tin ingot. The coaxial cable is electrically connected to the bottom metal ground plane through the metal vias. The plastic support pillars are mounted on the side of the intermediate dielectric layer. The intermediate dielectric layer is used to support the radiating structure and the grounding structure, providing physical support and electromagnetic isolation. The radiating structure includes a first L-shaped metal radiating patch, a second L-shaped metal radiating patch, and an equal amplitude power divider. The grounding structure includes a bottom metal ground. The first L-shaped metal radiating patch and the second L-shaped metal radiating patch serve as the array dual-radiating body. The unit is miniaturized by extending the equivalent current path through bending branches, and orthogonal electric field components are formed to excite circularly polarized electromagnetic waves. The equal-amplitude power divider is used to evenly distribute the input radio frequency energy, and to deliver excitation signals with consistent amplitude and synchronized phase to the first L-shaped metal radiating patch and the second L-shaped metal radiating patch. The bottom metal ground is used to adjust the current distribution of the first L-shaped metal radiating patch and the second L-shaped metal radiating patch respectively, and to correct the phase deviation of the orthogonal electric field. The metal via is used to connect the inner conductor of the coaxial cable to the bottom metal ground to form a power supply grounding loop; The tin block is used to achieve a stable weld between the inner conductor of the coaxial cable and the equal-amplitude power divider, ensuring stable transmission of the radio frequency excitation signal; The coaxial cable includes an inner conductor and an outer conductor, and the coaxial cable is used to feed radio frequency excitation signals to the antenna. The plastic support column is used to fix the intermediate medium layer.

2. The high-gain miniature circularly polarized monopole array antenna according to claim 1, characterized in that, The first L-shaped metal radiating patch and the second L-shaped metal radiating patch are symmetrically arranged on the upper surface of the dielectric substrate. Both the first L-shaped metal radiating patch and the second L-shaped metal radiating patch include an integrally bent horizontal radiating arm and a vertical radiating arm, wherein: The horizontal and vertical radiation arms are used to form two mutually perpendicular current radiation paths, which generate orthogonal electric field components with a 90° phase difference after feeding, thus exciting the circularly polarized radiation mode. The integrally bent structure is used to extend the equivalent current radiation path, thereby miniaturizing the radiation unit without increasing the substrate size.

3. The high-gain miniature circularly polarized monopole array antenna according to claim 2, characterized in that, The bottom metal ground includes a first grounding metal surface and a second grounding metal surface. The first grounding metal surface and the second grounding metal surface are integrally connected to form a complete reference ground plane. The edge contours of the first grounding metal surface and the second grounding metal surface have differentiated edge structures, wherein: The first grounding metal surface and the second grounding metal surface are used to form a coupling resonant structure with the first L-shaped metal radiating patch and the second L-shaped metal radiating patch on the corresponding side, respectively, so as to independently adjust the input impedance of the two current radiation paths. The differentiated edge structure is used to disturb the induced current under the first L-shaped metal radiating patch and the second L-shaped metal radiating patch respectively, regulate the phase difference of the orthogonal polarization components, and reduce the electromagnetic mutual coupling between units. The integrated, interconnected reference ground plane is used to provide a complete grounding loop and suppress antenna back radiation.

4. The high-gain miniature circularly polarized monopole array antenna according to claim 3, characterized in that, The equal-amplitude power divider is disposed between the first L-shaped metal radiating patch and the second L-shaped metal radiating patch, and adopts an integrated wiring structure with single-ended input and two symmetrical outputs, wherein: The single-ended input is used to connect to the inner conductor of the coaxial cable and receive external radio frequency excitation signals. The two symmetrical outputs are used to connect the first L-shaped metal radiating patch and the second L-shaped metal radiating patch respectively, so as to achieve equal output signal amplitude and phase synchronization.

5. A high-gain, small-sized circularly polarized monopole array antenna according to claim 4, characterized in that, The upper surface of the intermediate dielectric layer is also provided with a grounding metal patch, which is connected to the bottom metal ground through a metal via. The outer conductor of the coaxial cable is welded to the grounding metal patch, and electrical grounding with the bottom metal ground is achieved through the metal via.

6. The high-gain miniature circularly polarized monopole array antenna according to claim 5, characterized in that, The intermediate dielectric layer is a single-layer planar dielectric substrate without multi-layer dielectric stacking or three-dimensional parasitic metal components, and the cross-sectional height of the intermediate dielectric layer is equal to the substrate thickness.

7. A high-gain, small-sized circularly polarized monopole array antenna according to claim 6, characterized in that, The coaxial cable adopts a side-mounted single-point power supply layout, eliminating the need for external discrete power distribution devices and phase-shifting networks.

8. A design method for a high-gain, small-scale circularly polarized monopole array antenna, characterized in that, Includes the following modules: Determine the circular polarization and gain performance indicators of the array antenna, construct two sets of symmetrically arranged L-shaped radiating patches and an integrated equal amplitude power distribution line to form the upper radiating layer structure; Design a bottom metal grounding structure with differentiated profiles, independently control the surface current distribution of two sets of L-shaped radiating patches, broaden the impedance and axial ratio working bandwidth, and construct the bottom grounding layer structure. A side coaxial power supply component is introduced, and the inner conductor of the coaxial cable is connected to the input end of the equal amplitude power divider through a metal tin block. A power supply grounding loop is constructed with metal vias. The upper radiating layer, single-layer dielectric substrate, and feed grounding circuit are assembled and fixed to obtain a high-gain small circularly polarized monopole array antenna.

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