Miniaturized multi-band composite antenna

Abstract

The invention belongs to the technical field of navigation communication antennas, and particularly discloses a miniaturized multi-band composite antenna, which comprises a ring focus reflector antenna, a banyan array antenna and a frequency selective surface, the ring focus reflector antenna comprises a main reflector, an auxiliary reflector and a multi-ripple feed source, the concave surface of the main reflector is opposite to the convex surface of the auxiliary reflector, and the multi-ripple feed source is arranged at the axis of the main reflector. According to the miniaturized multi-band composite antenna and the assembly thereof provided by the invention, multi-band efficient radiation is realized in a limited space through cooperative layout of the ring focus reflector antenna, the special-shaped array antenna and the frequency selective surface in combination with optimal design of the multi-ripple feed source and the banyan antenna group, and meanwhile, inter-band interference is suppressed by using the frequency selective surface, so that the antenna efficiency is improved. The antenna has the advantages of compact structure, excellent multi-band cooperative work performance and strong electromagnetic compatibility.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of navigation communication antennas, and particularly relates to a miniaturized multi-band composite antenna. BACKGROUND

[0002] As a key front-end component of communication systems, the performance of an antenna directly affects the communication quality and working stability of the entire system. With the continuous evolution of communication technology, antennas are increasingly showing a development trend of miniaturization, wide frequency band and integration in structure, which puts higher requirements on the comprehensive performance of antennas.

[0003] In actual applications, especially in complex electromagnetic scenarios such as military communication and radar detection, multiple antenna units are often densely arranged in a limited platform to achieve multifunctional integration and spatial optimization. However, the co-location of multiple antennas will intensify the mutual coupling effect between units, causing a series of problems such as impedance mismatch, radiation pattern distortion and efficiency reduction, which seriously affect the performance of the antenna. In addition, since modern communication equipment needs to cover multiple frequency bands, the working stability of the antenna in a complex electromagnetic compatibility environment is severely challenged.

[0004] In summary, the composite antenna structure in the prior art has the problem that the performance deteriorates easily under interference when multiple frequency bands work cooperatively. SUMMARY

[0005] The present application provides a miniaturized multi-band composite antenna, which can solve the problem that the performance of the composite antenna structure in the prior art deteriorates easily under interference when multiple frequency bands work cooperatively.

[0006] A miniaturized multi-band composite antenna comprises: A Cassegrain reflector antenna, which comprises a main reflector, a sub-reflector and a multi-corrugated feed source, the concave surface of the main reflector is opposite to the convex surface of the sub-reflector, and the multi-corrugated feed source is arranged at the axis center of the main reflector; A banyan array antenna, which is arranged above the Cassegrain reflector antenna, and comprises a plurality of banyan antenna groups, each banyan antenna group comprising two perpendicular banyan antennas; A frequency selective surface, which is arranged between the Cassegrain reflector antenna and the banyan array antenna.

[0007] The present application provides a miniaturized multi-band composite antenna, which has the following beneficial effects, but is not limited to the following: The miniaturized multi-band composite antenna and the components thereof realize multi-band high-efficiency radiation in a limited space through the collaborative layout of the ring-focus reflector antenna, the special-shaped array antenna and the frequency selective surface, the combination of the multi-corrugated feed source and the optimization design of the banyan antenna group, the suppression of frequency band interference by the frequency selective surface, and the advantages of compact structure, excellent multi-band collaborative working performance and strong electromagnetic compatibility. Specifically, the ring-focus reflector antenna forms a compact structure through the cooperation of the main and auxiliary reflector surfaces, and the multi-corrugated feed source can support multiple working frequency bands at the same time. Specifically, the ring-focus reflector antenna can be a Ku1 and Ku2 band circularly polarized ring-focus reflector antenna. Each banyan antenna group of the banyan array antenna is composed of two orthogonally placed banyan antennas, forming a dual-polarized radiation unit, which can realize the resonance characteristics of different frequency bands. The frequency selective surface can effectively isolate the electromagnetic coupling between different frequency bands. The frequency selective surface is arranged between the ring-focus reflector antenna and the banyan array antenna, and this layered structure enables the antennas of each frequency band to work independently and collaboratively, significantly improving the working stability of the composite antenna in a complex electromagnetic environment.

[0008] Further, the multi-corrugated feed source comprises a multi-corrugated horn and a septum polarizer connected in sequence.

[0009] Further, the septum polarizer is composed of a stepped septum and a waveguide section arranged outside the stepped septum. The stepped septum is arranged in an uphill shape in the first direction.

[0010] Further, the first direction is from the bottom of the waveguide section to the top of the waveguide section.

[0011] Further, the septum is a multi-step stepped structure, and the number of steps of the stepped structure is not less than the level.

[0012] Further, the banyan antenna is provided with a metal block at the bottom, and the metal block is arranged on the frequency selective surface.

[0013] Further, the banyan antenna comprises a ground plate and two radiation arms arranged on the ground plate. The two radiation arms are arranged oppositely.

[0014] Further, the cross-sectional shape of the radiation arm comprises a first edge line, a second edge line, a third edge line and a fourth edge line connected end to end, and the first edge line, the third edge line and the fourth edge line are in arc shape.

[0015] Further, the second edge line is parallel to the axis of the ring-focus reflector antenna.

[0016] Further, the connection between the first edge line and the fourth edge line is in a circular arc shape. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings: Figure 1 A structure schematic view of a miniaturized multi-band composite antenna according to the present application; Figure 2 A structure front view of a miniaturized multi-band composite antenna according to the present application; Figure 3 A structure schematic view of a banyan tree antenna of a miniaturized multi-band composite antenna according to the present application; Figure 4 A structure schematic view of a multi-corrugated feed source of a miniaturized multi-band composite antenna according to the present application; Figure 5 A structure schematic view of a stepped partition of a miniaturized multi-band composite antenna according to the present application; Figure 6 A standing wave curve diagram of S1 / S2 two bands of a miniaturized multi-band composite antenna according to the present application; Figure 7 A standing wave curve diagram of Ku1 / Ku2 two bands of a miniaturized multi-band composite antenna according to the present application; Figure 8 A radiation pattern of S1 / S2 bands of a miniaturized multi-band composite antenna according to the present application; Figure 9 A radiation pattern of Ku1 / Ku2 bands of a miniaturized multi-band composite antenna according to the present application.

[0018] Explanation of reference signs: 100, a Cassegrain reflector antenna; 1, a main reflector; 2, a sub-reflector; 3, a multi-corrugated feed source; 200, a banyan tree array antenna; 4, a banyan tree antenna; 5, a frequency selective surface; 6, a metal block; 7, a partition circular polarizer; 71, a stepped partition; 72, a waveguide section; 401, a ground plate; 402, a radiation arm; 403, a first edge line; 404, a second edge line; 405, a third edge line; 406, a fourth edge line; 407, a feed double line; 408, line A; 409, line B; 410, a feed joint; 411, a short-circuit line. DETAILED DESCRIPTION

[0019] In order to make the purposes, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings which show the embodiments according to the present application. It should be understood that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments described in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort will fall within the scope of protection of the present application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "comprising," "comprises" and "comprised of" as used herein are synonymous with "including," "includes" or "containing," "contains," and are inclusive or open-ended and do not exclude additional, unrecited elements or method steps; the terms "a," "an" and "the" used in the specification and the appended claims, unless qualified by a specific recitation, are used generically, not specifically, to mean "one or more." The use of "about" in the specification in relation to a particular recited numerical value means that the exact value is "approximately" or "around" the recited numerical value, that is, within 10% of the recited numerical value, preferably within 1% thereof, and more preferably within 0.1% thereof.

[0021] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", and the like is based on the orientation or positional relationship shown in the drawings, and is only for the purpose of facilitating the description of the present application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0022] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection", "attaching" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integral connection; can be directly connected, or indirectly connected through an intermediate medium; can be internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0023] It should be emphasized that when the term "comprising / including" is used in this specification, it is used to explicitly indicate the presence of the stated feature, integer, step, or component, but does not exclude the presence or addition of one or more other features, integers, steps, parts, or groups of features, integers, steps, or parts.

[0024] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, B and / or C can represent: B existing alone, B and C existing simultaneously, or C existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0025] In existing technologies, antennas, as key components of communication systems, directly affect communication quality and stability. With the development of communication technology, antenna structures are trending towards miniaturization, wider bandwidth, and integration. In scenarios such as military communications and radar detection, multiple antenna elements often need to be densely arranged within a limited platform. However, co-location of multiple antennas can exacerbate mutual coupling effects, leading to problems such as impedance mismatch and radiation pattern distortion. Existing composite antenna structures are susceptible to electromagnetic interference, resulting in performance degradation when operating across multiple frequency bands.

[0026] To address the aforementioned issues, research revealed that traditional structures struggle to effectively isolate signals from different frequency bands when multi-band antennas operate collaboratively, leading to decreased radiation efficiency. By analyzing electromagnetic field distribution characteristics, a proposal was made to combine a reflector antenna with an array antenna, utilizing a frequency-selective surface to achieve frequency band isolation. Further research showed that this composite antenna can operate simultaneously in four frequency bands: S1 / S2 / Ku1 / Ku2. Its compact structure and ingenious installation significantly reduce the antenna's envelope size, and its reliable performance allows the four multi-band signals to operate independently with consistent phase centers.

[0027] Based on the above, such as Figures 1 to 2 As shown, an embodiment of the present invention provides a miniaturized multi-band composite antenna, including a ring focal reflector antenna 100, a banyan tree array antenna 200, and a frequency selective surface 5; Specifically, the ring-focal reflector antenna 100 includes a main reflector 1, a sub-reflector 2, and a multi-corrugated feed 3. The concave surface of the main reflector 1 is opposite to the convex surface of the sub-reflector 2, and the multi-corrugated feed 3 is located at the axis of the main reflector 1. The banyan tree array antenna 200 is positioned above the ring focal reflector antenna 100. The banyan tree array antenna 200 includes several banyan tree antenna groups, and each banyan tree antenna group includes two perpendicular banyan tree antennas 4. The frequency selective surface 5 is located between the ring focal reflector antenna 100 and the banyan tree array antenna 200.

[0028] Among them, the ring-focus reflector antenna 100 refers to a reflector antenna that uses a main and sub-reflectors 2 to form a ring-focus structure. The concave surface of the main reflector 1 and the convex surface of the sub-reflector 2 are arranged opposite each other to optimize the electromagnetic wave reflection path. The multi-corrugated feed 3 is located at the axis to enable multi-band signal feeding. The banyan tree array antenna 200 refers to an antenna array composed of multiple banyan tree antenna groups. In each banyan tree antenna group, two mutually perpendicular banyan tree antennas 4 can respectively cover the radiation requirements of different polarization directions. The frequency selective surface 5 refers to an electromagnetic shielding layer with frequency selective characteristics, which can selectively transmit or reflect electromagnetic waves of specific frequency bands, for example, by using a periodic metal patch structure.

[0029] Specifically, the ring focal reflector antenna 100 forms a compact structure through the curved surface cooperation of the main and sub reflectors 2, and the multi-corrugated feed 3 can support multiple operating frequency bands simultaneously; specifically, the ring focal reflector antenna 100 can be a circularly polarized ring focal reflector antenna for two bands, Ku1 and Ku2.

[0030] The banyan tree array antenna 200 can be configured with four groups, which expand the radiation pattern coverage range through the four groups of banyan tree antenna groups arranged in a rectangular array. Specifically, the banyan tree array antenna 200 consists of four groups of banyan tree antenna groups (two mutually perpendicular banyan tree antennas 4) forming a banyan tree array antenna for the S1 and S2 bands.

[0031] In addition, a metal block 6 is provided at the bottom of the banyan tree antenna 4, and the metal block 6 is located on the frequency selective surface 5. Specifically, the metal block 6 and the frequency selective surface 5 are combined to serve as the metal ground of the banyan tree array antenna for the S1 and S2 bands.

[0032] The present invention provides a miniaturized multi-band composite antenna, which is a circularly polarized composite antenna containing four frequency bands. It is small in size, low in profile, compact in structure, and reliable in performance. The phase centers of the multi-band antenna are consistent, and it has a wide range of applications in the field of communication, especially in navigation and communication antennas for airborne and shipboard applications.

[0033] Specifically, the ring-focus reflector antenna 100 forms a compact structure through the curved surface cooperation of the main and sub-reflectors 2. The multi-corrugated feed 3 can simultaneously support multiple operating frequency bands. The ring-focus reflector antenna 100 can be a circularly polarized ring-focus reflector antenna for both Ku1 and Ku2 bands. The banyan tree array antenna 200 serves as a banyan tree array antenna for both S1 and S2 bands. The frequency selective surface 5 acts as an electromagnetic isolation layer, allowing the operating frequency band of the ring-focus reflector antenna 100 to pass through while reflecting the operating frequency band of the banyan tree array antenna 200, thereby reducing mutual interference between the two. Based on the above, this miniaturized multi-band composite antenna can operate simultaneously in four frequency bands: S1 / S2 / Ku1 / Ku2.

[0034] Compared with existing technologies, traditional composite antennas mostly adopt a stacked layout and lack effective frequency band isolation measures. This solution introduces a frequency selective surface 5 to add electromagnetic isolation on top of physical isolation. At the same time, by introducing a combined structure of a ring focal reflector antenna 100 and a banyan tree array antenna 200, mutual coupling effects are reduced through spatial diversity and polarization diversity mechanisms while maintaining a compact layout.

[0035] Through the above technical solution, this application can achieve efficient collaborative operation of multi-band signals, simultaneously meeting the requirements of operating four frequency bands (S1 / S2 / Ku1 / Ku2) within a limited space. The frequency selection surface 5 effectively suppresses electromagnetic interference between different frequency bands, and the orthogonal layout of the banyan tree antenna array reduces cross-polarization interference, thereby improving the operational stability of the composite antenna in complex electromagnetic environments.

[0036] like Figures 1 to 4 As shown, in some embodiments of the present invention, the multi-corrugated feed 3 includes a multi-corrugated horn and a partition circular polarizer 7 connected together. Among them, the multi-corrugated horn refers to a horn-shaped radiator with a periodic corrugated structure, which can be achieved by creating annular grooves on the metal surface. The corrugated structure can expand the operating bandwidth and suppress the generation of higher-order modes. The partitioned circular polarizer 7 refers to a waveguide conversion device with a built-in metal partition, which can be achieved by setting a stepped metal partition inside a rectangular waveguide. By adjusting the geometric parameters of the partition, the phase difference of the electromagnetic wave can be controlled, converting linearly polarized waves into circularly polarized waves.

[0037] Specifically, the septum circular polarizer 7 consists of a stepped septum 71 and a waveguide section 72 disposed outside the stepped septum 71; The multi-corrugated horn and the partition circular polarizer 7 are fixedly connected to form an integral structure. The corrugation period of the multi-corrugated horn can be set to the millimeter level, for example, the corrugation depth is 0.5-2 mm, and the number of corrugations can be 8-12. Multi-band impedance matching is achieved by optimizing the corrugation parameters. The stepped partition 71 of the partition circular polarizer 7 extends along the waveguide axis, and its height gradient change forms an equivalent dielectric loading effect, causing a phase difference in the orthogonal polarization components. After the two are combined, the multi-corrugated horn is responsible for broadband signal radiation, and the partition circular polarizer 7 realizes the polarization conversion function, jointly improving the antenna's working stability in complex electromagnetic environments.

[0038] Compared with existing technologies, traditional feeds often employ a separate design of a single-corrugated horn and a dielectric-loaded polarizer, resulting in large size and limited bandwidth. This solution achieves multi-band coverage while maintaining a compact size through an integrated structural design. The stepped septum 71 offers superior phase control accuracy compared to traditional inclined septums.

[0039] Through the above technical solutions, this application effectively solves the problem of efficiency reduction caused by impedance mismatch during multi-band signal transmission. By optimizing the feed structure, it reduces mutual coupling interference between adjacent frequency bands, enabling the composite antenna to maintain stable radiation performance even under dense arrangement conditions.

[0040] like Figures 1 to 4 As shown, in some embodiments of the present invention, the stepped partition 71 is arranged in an upward slope in a first direction; the first direction is the direction from the bottom of the waveguide section 72 to the top of the waveguide section 72; The stepped partition 71 refers to a metal partition component with a stepped structure, which can be implemented using a multi-level stepped structure with gradually changing heights. The change in step height creates a continuous impedance transition, reducing electromagnetic wave reflection loss. The waveguide section 72 refers to the metal cavity structure surrounding the stepped partition 71, which can be implemented using a conductive material with a rectangular or circular cross-section. It is used to constrain the electromagnetic wave propagation path and control the polarization direction. The first direction refers to the vertical extension direction from the bottom to the top of the waveguide section 72. The stepped partition 71 forms a gradual slope in this direction, causing a phase difference in the electromagnetic wave during propagation to achieve circular polarization conversion.

[0041] Specifically, the stepped septum 71 and the waveguide section 72 together constitute a polarization conversion structure. The gradually changing slope design of the stepped septum 71 generates a continuous phase delay as the electromagnetic wave propagates within the waveguide, thereby converting the linearly polarized wave into a circularly polarized wave. The multi-stage stepped structure of the stepped septum 71 reduces reflection loss caused by impedance abrupt changes, while the closed structure of the waveguide section 72 suppresses external electromagnetic interference. The upward-sloping arrangement of the stepped septum 71 creates a uniform phase gradient along the propagation path from the bottom to the top of the waveguide section 72, ensuring the directional consistency of the circularly polarized wave.

[0042] Compared to existing technologies, traditional circular polarizers often employ straight-plate partitions or single-step structures, which are prone to enhanced reflection and limited polarization purity due to impedance abrupt changes. This solution, through a multi-step gradient design, achieves smoother impedance matching while maintaining a compact structure, reducing return loss and expanding the operating bandwidth.

[0043] Through the above technical solutions, this application improves the impedance matching characteristics of the partition circular polarizer 7, reduces energy loss caused by electromagnetic wave reflection, enhances the phase consistency of the circular polarized wave, and improves the polarization stability and signal transmission efficiency of the antenna in complex electromagnetic environments.

[0044] like Figures 1 to 5 As shown, in some embodiments of the present invention, the partition 71 is a multi-stage stepped structure, and the number of stages of the stepped structure is not less than 5. A multi-level stepped structure refers to a continuous transitional form formed by multiple stepped partitions. This can be achieved using segmented metal sheet stacking or integrated molding processes. The electromagnetic wave propagation path is guided by the gradual change in step height. A minimum of five levels means the stepped structure contains at least five independent height levels, which can be achieved through uniform or non-uniform height differences. Increasing the number of levels enhances the ability to control the phase distribution of electromagnetic waves.

[0045] The stepped structure has at least five stages, which can cover the electromagnetic wave phase compensation requirements across a wider frequency band and avoid abrupt changes in the high-frequency signal transmission path due to insufficient stages. In complex multi-frequency operating scenarios, this structure gradually adjusts the electromagnetic field distribution through multiple levels of height difference, suppressing mutual interference between signals of different frequency bands.

[0046] like Figures 1 to 4 As shown, in some embodiments of the present invention, the banyan tree antenna 4 includes a ground plane 401 and two radiating arms 402 disposed on the ground plane 401; the two radiating arms 402 are disposed opposite to each other. The banyan tree antenna 4 refers to an antenna unit consisting of a ground plane 401 and two opposing radiating arms 402. It can be implemented using microstrip patch or printed circuit board technology. The specific shape of its radiating arms 402 optimizes current distribution to cover multiple frequency bands. The metal block 6 refers to a block-shaped structure with conductive properties, which can be made of copper, aluminum, or alloy materials. It enhances the grounding effect of the ground plane 401 of the banyan tree antenna 4 through physical contact, suppressing interference from surface current diffusion to adjacent antennas. The frequency selective surface 5 refers to a filter structure with periodic electromagnetic characteristics, which can be implemented using a metal patch array or aperture array. It isolates electromagnetic wave transmission in different frequency bands through bandpass or bandstop characteristics.

[0047] Specifically, the bottom sides of the two radiating arms 402 protrude downwards to form a double feed line 407; of the double feed lines 407, the line on the left is marked as line A 408 and the line on the right is marked as line B 409. Line A 408 is connected to the ground plane 401, and line B 409 is provided with a feed connector 410. One end of the feed connector 410 that passes through the ground plane 401 is provided on the metal block 6.

[0048] In addition, both radiating arms 402 are provided with short circuits 411 at their bottom, which are connected to the ground plane 401.

[0049] The design of the radiating arm 402, combined with a specific dual-wire feed structure 407, not only achieves efficient radiation across multiple frequency bands but also ensures stable signal transmission and low loss. Simultaneously, the tight connection between the metal block 6 and the ground plane 401 enhances grounding and effectively suppresses interference that may occur to adjacent antennas due to surface current diffusion, guaranteeing good isolation between the multi-antenna system. The application of the frequency selective surface 5 allows for precise isolation of electromagnetic waves in different frequency bands based on preset bandpass or bandstop characteristics, ensuring independent and clear transmission for each band, thereby improving the performance and reliability of the entire multi-band composite antenna.

[0050] Furthermore, given that the banyan tree array antenna 200 comprises several banyan tree antenna groups, and each banyan tree antenna group consists of two mutually perpendicular banyan tree antennas 4. Here, "mutually perpendicular" means that in each banyan tree antenna group, the length direction of one banyan tree antenna 4 is perpendicular to the length direction of the other banyan tree antenna 4.

[0051] like Figures 1 to 4 As shown, in some embodiments of the present invention, the cross-sectional shape of the radiating arm 402 includes a first edge line 403, a second edge line 404, a third edge line 405, and a fourth edge line 406 that are connected end to end, and the first edge line 403, the third edge line 405, and the fourth edge line 406 are all arc-shaped. The second edge line 404 is parallel to the axis of the ring focal reflector antenna 100; The connection between the first edge line 403 and the fourth edge line 406 is an arc-shaped transition; Specifically, the cross-sectional shape of the radiating arm 402 refers to the cross-sectional profile of the antenna radiating element perpendicular to the current propagation direction. This can be achieved by splicing multiple curve segments to form a closed path, and the electromagnetic field distribution can be controlled by adjusting the curvature of the curves. The arc shapes of the first edge line 403, the third edge line 405, and the fourth edge line refer to geometric profiles with continuous curvature changes. This can be achieved using Bézier curves or circular arc segments to optimize the smoothness of the current path. The arc-shaped transition refers to a gradual curvature design in the connection area between adjacent edge lines. This can be achieved using rounded corners or gradually curving surfaces to eliminate field strength distortion caused by abrupt right-angle changes.

[0052] Compared to existing technologies, traditional composite antenna radiating arms 402 often employ rectangular or trapezoidal cross-sections. Their right-angled edges are prone to current phase lag, leading to pattern splitting and efficiency degradation in the high-frequency band. This solution, through the coordinated design of curved edge lines and circular transitions, maintains phase consistency of the current across a wide frequency band while reducing mutual interference between electromagnetic fields in adjacent frequency bands. Compared to stepped or polygonal cross-sections, the curved profile is more effective in suppressing surface wave resonances and improving radiation stability during multi-band collaborative operation.

[0053] To verify the performance of the miniaturized multi-band composite antenna provided by this invention, Figure 6 The standing wave ratio (SWR) curves for the two frequency bands S1 and S2 of this invention are provided. As can be seen from the curves, the standing wave ratio of this miniaturized multi-band composite antenna is ≤2 in the frequency bands of 1.8GHz~2.4GHz and 2.7GHz~3.4GHz. Figure 7 The standing wave curves for the Ku1 / Ku2 frequency bands of this invention are based on... Figure 7 It can be seen that the miniaturized multi-band composite antenna has a standing wave ratio of ≤2 in the 12GHz~14GHz and 15GHz~16GHz frequency bands; Figure 8 The radiation pattern of the S1 and S2 frequency bands of this invention has a maximum gain of 15 dB. Figure 9 The radiation pattern for the Ku1 and Ku2 frequency bands of this invention is shown, with a maximum gain of 30dB.

[0054] The antenna phase centers of the four frequency bands are aligned.

[0055] based on Figures 6 to 9 The data shows that this invention designs a circularly polarized composite antenna that can operate simultaneously in four frequency bands: S1 / S2 / Ku1 / Ku2. It features a compact structure, ingenious installation, and significantly reduced antenna envelope size. Its performance is reliable, with the four multi-band signals operating independently and maintaining consistent phase centers. This composite antenna has a VSWR ≤ 2, and its relative bandwidth can be extended to 28.6%, covering four frequency bands: 1.8GHz–2.4GHz, 2.7GHz–3.4GHz, 12GHz–14GHz, and 15GHz–16GHz. The maximum gain for S1 / S2 is 15dB, and the maximum gain for Ku1 / Ku2 is 30dB.

[0056] This miniaturized multi-band composite antenna exhibits excellent radiation stability when operating in tandem across multiple bands, thanks to its ring-focal reflector antenna design and banyan tree array antenna design, which effectively suppresses surface wave resonance. Its compact structural design not only reduces the overall envelope size but also achieves independent operation of the four signals through a clever mounting method, ensuring low mutual interference between the bands. In terms of performance, the antenna maintains a low VSWR over a wide bandwidth, and the gain parameters of each band meet or exceed the expected design requirements, fully validating its practicality and reliability as a multi-band composite antenna.

[0057] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A miniaturized multi-band composite antenna, characterized in that, include: A ring-focus reflector antenna (100) includes a main reflector (1), a sub-reflector (2), and a multi-corrugated feed (3). The concave surface of the main reflector (1) is opposite to the convex surface of the sub-reflector (2), and the multi-corrugated feed (3) is located at the axis of the main reflector (1). Banyan tree array antenna (200), the banyan tree array antenna (200) is located above the ring focal reflector antenna (100), the banyan tree array antenna (200) includes several banyan tree antenna groups, the banyan tree antenna group includes two perpendicular banyan tree antennas (4). A frequency selective surface (5) is disposed between the annular focal reflector antenna (100) and the banyan tree array antenna (200).

2. The miniaturized multi-band composite antenna according to claim 1, characterized in that, The multi-corrugated feed (3) includes a multi-corrugated horn and a partition circular polarizer (7) connected together.

3. A miniaturized multi-band composite antenna according to claim 2, characterized in that, The diaphragm circular polarizer (7) consists of a stepped diaphragm (71) and a waveguide section (72) located outside the stepped diaphragm (71); The stepped partition (71) is arranged in an uphill shape in the first direction.

4. A miniaturized multi-band composite antenna according to claim 3, characterized in that, The first direction is from the bottom of the waveguide segment (72) to the top of the waveguide segment (72).

5. A miniaturized multi-band composite antenna according to claim 3, characterized in that, The partition (71) is a multi-stage stepped structure, and the number of stages of the stepped structure is not less than 5.

6. A miniaturized multi-band composite antenna according to claim 1, characterized in that, The bottom of the banyan tree antenna (4) is provided with a metal block (6), which is located on the frequency selection surface (5).

7. A miniaturized multi-band composite antenna according to claim 6, characterized in that, The banyan tree antenna (4) includes a ground plane (401) and two radiating arms (402) disposed on the ground plane (401). The two radiating arms (402) are arranged opposite each other.

8. A miniaturized multi-band composite antenna according to claim 7, characterized in that, The cross-sectional shape of the radial arm (402) includes a first edge line (403), a second edge line (404), a third edge line (405), and a fourth edge line (406) that are connected end to end. The first edge line (403), the third edge line (405), and the fourth edge line (406) are all arc-shaped.

9. A miniaturized multi-band composite antenna according to claim 8, characterized in that, The second edge line (404) is parallel to the axis of the ring focal reflector antenna (100).

10. A miniaturized multi-band composite antenna according to claim 8, characterized in that, The connection between the first edge line (403) and the fourth edge line (406) is an arc-shaped transition.

Images