A small frequency ratio broadband dual-frequency dual-circular polarization coaxial common aperture horn antenna unit

Abstract

The present invention relates to a small-frequency-ratio, broadband, dual-frequency, dual-circularly-polarized, coaxial, common-aperture horn antenna unit, belonging to the field of electronic science and technology. The unit comprises a low-frequency horn wall, a high-frequency horn wall, a low-frequency feeding ridge, a low-frequency dual-circular-polarized synthesis network, a coaxial sub-element, a high-frequency dual-circular-polarized synthesis network, and a high-frequency feeding probe. The low-frequency horn wall is placed outside the high-frequency horn wall, and together they form the side wall of the horn antenna. The low-frequency feeding ridge is placed between the low-frequency horn wall and the high-frequency horn wall, and is connected to the low-frequency horn wall. The low-frequency dual-circular-polarized synthesis network is placed below the low-frequency horn wall and is connected to the low-frequency horn wall via a coaxial sub-element placed inside the bottom of the low-frequency horn wall. The high-frequency dual-circular-polarized synthesis network is placed below the high-frequency horn wall and is connected to the high-frequency horn wall. The high-frequency feeding probe is placed on the side of the high-frequency dual-circular-polarized synthesis network. The addition of the low-frequency feeding ridge effectively improves the bandwidth of the low-frequency operation, and realizes a small-frequency-ratio, broadband design of the dual-band common-aperture horn.

Description

Technical Field

[0001] The present invention belongs to the field of electronic science and technology, and in particular relates to a small-frequency-ratio, broadband, dual-frequency, dual-circularly-polarized, coaxial, and common-aperture horn antenna unit. Background Art

[0002] Array antennas are widely used because they can achieve a variety of different beamforms by varying the phase and amplitude of the feeds to each element. Traditional arrays are often limited to single-band operation, requiring multiple array planes for multi-band operation, significantly reducing the antenna array's aperture utilization. A co-aperture antenna array places multiple antennas with different frequency bands and functions within the same radiating aperture, ensuring independent operation without interference through appropriate design. Co-aperture antennas not only achieve multi-band radiation within a limited radiating surface, but also allow for independent control of the radiation performance of antenna arrays in different frequency bands. Integrating antennas with multiple frequency bands and polarizations into the same aperture maximizes aperture utilization and improves aperture reuse efficiency, playing a key role in reducing antenna system and payload platform costs and enhancing the system's multi-band, multi-functional integration capabilities. Horn antennas, with their high phase center stability, are widely used in satellite measurement and control. To achieve multi-band design, horn antennas can be designed in either a co-aperture or co-aperture configuration. The common aperture format, however, has an antenna aperture related to the low-frequency cutoff frequency, making it impossible to suppress grating lobes when forming an array. A common aperture dual-band horn antenna would have a smaller aperture and be more suitable for array formation. However, because traditional coaxial probe-fed common aperture horn antennas can only achieve a frequency ratio of approximately 5x when the bandwidth requirement is 30%-40%, it is of practical significance to propose a low-frequency-ratio, broadband, dual-band, dual-circularly polarized coaxial common aperture horn antenna. Summary of the Invention

[0003] The technical problems to be solved by the present invention are:

[0004] In order to avoid the shortcomings of the prior art, the present invention provides a small frequency ratio broadband dual-band dual-circular polarization coaxial common aperture horn antenna unit, which is used to solve the small frequency ratio design problem of the common aperture dual-band horn antenna.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A small frequency ratio broadband dual-frequency dual-circular polarization coaxial common aperture horn antenna unit, characterized by comprising: a low-frequency horn wall, a high-frequency horn wall, a low-frequency feeding ridge, a low-frequency dual-circular polarization synthesis network, a coaxial sub-element, a high-frequency dual-circular polarization synthesis network and a high-frequency feeding probe;

[0007] The low-frequency speaker wall is placed on the outside of the high-frequency speaker wall, and together they form the side wall of the horn antenna;

[0008] The low-frequency feed ridge is placed between the low-frequency speaker wall and the high-frequency speaker wall and is connected to the low-frequency speaker wall;

[0009] The low-frequency dual circular polarization synthesis network is placed below the low-frequency speaker wall and is connected to the low-frequency feeding ridge via a coaxial sub-coaxial sub-coil placed inside the bottom of the low-frequency speaker wall;

[0010] The high-frequency dual circular polarization synthesis network is placed below the high-frequency speaker wall and connected to the high-frequency speaker wall;

[0011] The high-frequency feeding probe is placed on the side of the high-frequency dual circular polarization synthesis network.

[0012] A further technical solution of the present invention is that the low-frequency speaker wall is divided into two parts: a bottom surface and a side wall, wherein the upper half of the side wall gradually opens.

[0013] A further technical solution of the present invention is that the high-frequency speaker wall is only composed of side walls and does not include a bottom surface, wherein the side walls are divided into a lower half with a constant diameter and an upper half that gradually opens.

[0014] A further technical solution of the present invention is as follows: the low-frequency feeding ridges include four, evenly distributed around the central axis of the low-frequency speaker wall; the upper half is connected to the side wall of the low-frequency speaker wall, the lower half is an impedance matching section, and there is a gap between the lower half and the side wall of the low-frequency speaker wall.

[0015] A further technical solution of the present invention is as follows: the low-frequency band dual circular polarization synthesis network is in the shape of a ring structure, which is a multi-layer dielectric substrate with 4 copper surfaces, and is pressed from multiple dielectric substrates with printed circuits. After passing through the low-frequency band dual circular polarization synthesis network, the radio frequency signal is divided into four signals with equal amplitude and sequential phases.

[0016] A further technical solution of the present invention is as follows: the high-frequency band dual circular polarization synthesis network is divided into two parts, one part is a transition section that transmits the radio frequency signal from the circular waveguide section to the rectangular section; the other part is a rectangular waveguide with a side length of 5, and the center of the rectangular waveguide is a 5-step stepped transformation section to realize the formation of circular polarization of the high-frequency signal.

[0017] A further technical solution of the present invention includes a medium guide rod, which is located on the top of the high-frequency speaker wall.

[0018] A further technical solution of the present invention is that the dielectric guide rod is divided into two parts, the upper part is a radiation section, which is formed into two gradually tapering cones, and the lower part is a 4th-order gradually tapering impedance matching section.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a low-ratio, broadband, dual-band, dual-circularly polarized coaxial common-aperture horn antenna unit. Based on a dual-band common-aperture horn antenna, the addition of a low-band feed ridge effectively improves the low-band operating bandwidth, achieving a low-ratio, broadband design for the dual-band common-aperture horn. Furthermore, the dual-circularly polarized feed network and antenna are integrated. This unit has the advantages of a simple structure, small lateral dimensions, stable and reliable electrical performance, and ease of mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0022] Figure 1 This is a diagram showing the overall structure of an antenna according to an embodiment of the present invention;

[0023] Figure 2 An exploded view of an antenna according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of a low-frequency speaker wall of an antenna according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the high-frequency speaker wall of the antenna according to an embodiment of the present invention;

[0026] Figure 5 Schematic diagram of a low-frequency dual-polarization synthesis network of an antenna according to an embodiment of the present invention;

[0027] Figure 6 Schematic diagram of the coaxial antenna of an embodiment of the present invention;

[0028] Figure 7 Schematic diagram of a high-frequency dual circular polarization synthesis network of an antenna according to an embodiment of the present invention;

[0029] Figure 8 Schematic diagram of a dielectric guide rod of an antenna according to an embodiment of the present invention;

[0030] Figure 9 Schematic diagram of a high-frequency feeding probe of an antenna according to an embodiment of the present invention;

[0031] Figure 10 The voltage standing wave ratio of the dual circular polarization port in the low-frequency band of the antenna according to the embodiment of the present invention;

[0032] Figure 11 This is the 1.7 GHz radiation pattern of the antenna according to the embodiment of the present invention;

[0033] Figure 12 This is the 2.4 GHz radiation pattern of the antenna according to the embodiment of the present invention;

[0034] Figure 13The voltage standing wave ratio of the dual circular polarization port in the high frequency band of the antenna according to the embodiment of the present invention;

[0035] Figure 14 This is the 5.1GHz radiation pattern of the antenna according to the embodiment of the present invention;

[0036] Figure 15 This is the 6.0 GHz radiation pattern of the antenna according to the embodiment of the present invention.

[0037] In the picture:

[0038] 1- low-frequency speaker wall, 2- high-frequency speaker wall, 3- low-frequency feeding ridge, 4- low-frequency dual circular polarization synthesis network, 5- coaxial sub, 6- high-frequency dual circular polarization synthesis network, 7- dielectric guide rod, 8- high-frequency feeding probe. DETAILED DESCRIPTION

[0039] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0040] refer to Figure 1-Figure 2 The present invention provides a low-frequency-ratio, broadband, dual-band, dual-circularly-polarized coaxial common-aperture horn antenna unit. The unit comprises eight components: a low-frequency horn wall 1, a high-frequency horn wall 2, a low-frequency feed ridge 3, a low-frequency dual-circular-polarization synthesis network 4, a coaxial conductor 5, a high-frequency dual-circular-polarization synthesis network 6, a dielectric guide rod 7, and a high-frequency feed probe 8. The low-frequency horn wall 1 is positioned outside the high-frequency horn wall 2, forming the sidewalls of the horn antenna. The low-frequency feed ridge 3 is positioned between the low-frequency and high-frequency horn walls 1 and connected to the low-frequency horn wall 1. The low-frequency dual-circular-polarization synthesis network 4 is positioned below the low-frequency horn wall 1 and connected to the low-frequency feed ridge 3 via a coaxial conductor 5 positioned within the bottom of the low-frequency horn wall 1. The high-frequency dual-circular-polarization synthesis network 6 is positioned below the high-frequency horn wall 2 and connected to the high-frequency horn wall 2. The high-frequency feed probe 8 is positioned to the side of the high-frequency dual-circular-polarization synthesis network 6, and the dielectric guide rod 7 is positioned on top of the high-frequency horn wall 2.

[0041] The following is a detailed description of each component:

[0042] like Figure 3 As shown, it is a structural diagram of the low-frequency speaker wall 1. The low-frequency speaker wall 1 is made of aluminum and can be divided into two parts: the bottom and the side wall. The lower half of the side wall is 50mm high and 96mm in diameter, while the upper half of the side wall gradually opens to 52mm in height and gradually opens to 114mm.

[0043] like Figure 3 As shown, the low-frequency feed ridges 3 are located on the inner side of the side wall of the low-frequency speaker wall 1. There are four of them, evenly distributed around the central axis of the low-frequency speaker wall 1. Each low-frequency feed ridge 3 is divided into two sections, the upper section of which is connected to the side wall of the low-frequency speaker wall 1, and the lower section is an impedance matching section. There is a gap of 5mm between the lower section and the side wall of the low-frequency speaker wall 1. The height of the lower section is 30.5mm, and the height of the upper section is 63.4mm. There is a gap of 1mm between the bottom of the low-frequency feed ridge 3 and the bottom surface of the low-frequency speaker wall 1.

[0044] like Figure 4 Figure 2 shows the structure of tweeter wall 2. Similar to woofer wall 1, tweeter wall 2 is made of aluminum. Located inside woofer wall 1, tweeter wall 2 consists of a lower section with a constant diameter and a gradually expanding upper section. However, unlike woofer wall 1, tweeter wall 2 consists only of side walls, not a bottom. The lower section has a diameter of 38mm and a height of 93mm, while the upper section gradually expands to a diameter of 44mm and a height of 10mm.

[0045] like Figure 5 Figure 4 shows the structure of the low-frequency dual circular polarization synthesis network 4, which is placed below the bottom surface of the low-frequency speaker wall 1. The ring-shaped structure consists of a four-layer copper multi-layer dielectric substrate with a dielectric constant of 3.55. The network is formed by pressing multiple dielectric substrates with printed circuits. The RF signal is split into four signals of equal amplitude and sequential phase.

[0046] like Figure 6 As shown in FIG. 1 , a schematic diagram of the structure of the coaxial sub-assembly 5 is shown. The structure can be divided into three parts: a core wire, an insulating layer, and an outer conductor. The core wire is a cylinder, and the insulating layer and the outer conductor are an annular cylindrical structure. The coaxial sub-assembly 5 is placed inside the bottom plate of the low-frequency speaker wall 1 and is embedded in the bottom plate as a whole. The thickness of the core wire of the coaxial sub-assembly 5 is 2 mm. The upper part is connected to the low-frequency feed ridge 3, and the lower part is connected to the low-frequency dual circular polarization synthesis network 4. The outer diameter of the insulating layer is 6 mm, and the height of the insulating layer and the outer conductor is consistent with the thickness of its bottom plate.

[0047] like Figure 7 As shown in the figure, it is a schematic diagram of the structure of the high-frequency dual circular polarization synthesis network 6. The high-frequency dual circular polarization synthesis network 6 is placed below the high-frequency speaker wall 2 and can be divided into two parts. The first is a transition section that transmits the RF signal from the circular waveguide section to the rectangular section. Its height is 28.5mm. Below it is a rectangular waveguide with a side length of 34mm, and its center is a 5-step stepped transformation section to achieve the formation of circular polarization of the high-frequency signal.

[0048] like Figure 8Figure 2 shows the structure of the dielectric guide rod 7, which is placed above the high-frequency speaker wall 2. The dielectric guide rod 7 is divided into two sections. The upper section is the radiating section, forming two tapering cones with lengths of 18 mm and 220 mm, respectively, and diameters that gradually decrease from 38 mm to 24 mm and finally to 16 mm. The lower section is a fourth-order, gradually tapering impedance matching section. This section focuses electromagnetic waves and improves their directionality.

[0049] like Figure 9 As shown, it is a schematic structural diagram of the high-frequency feeding probe 8. The high-frequency feeding probe 8 is placed inside the side wall of the high-frequency dual circular polarization synthesis network 6. Its core wire extends into the interior of the high-frequency dual circular polarization synthesis network 6 and is divided into two sections with a total length of 9.3 mm. The distal end length is 1.3 mm and the diameter is 2.4 mm, while the proximal end length is 8 mm and the diameter is 1 mm.

[0050] The results of the technical embodiments of the present invention are further illustrated by simulation:

[0051] 1. Simulation content:

[0052] Please refer to Figure 10-15 The voltage standing wave ratio, radiation pattern and gain characteristics of the antenna in the above technical embodiment were simulated and calculated using simulation software.

[0053] 2. Simulation results:

[0054] Figure 10 The characteristic of the voltage standing wave ratio changing with the operating frequency obtained by simulating the low frequency band of the antenna in the technical embodiment is as follows: Figure 10 It can be seen that the low frequency band of the antenna of the embodiment of the present invention works in the L and S bands, achieving a relative bandwidth of 34%. Figure 13 It can be seen that the high frequency band of the antenna in the embodiment of the present invention operates in the C band, achieving a relative bandwidth of 16%.

[0055] from Figure 11-12 This is the low-frequency related directional pattern of the antenna of the embodiment of the present invention. The antenna of the embodiment of the present invention has a gain of more than 7dB in the L and S (ie, low frequency band) working frequency bands.

[0056] from Figure 14-15 This is a high-frequency related directional diagram of the antenna of an embodiment of the present invention. The antenna of the embodiment of the present invention has a gain of more than 15dB in the working frequency band C (ie, high frequency band).

[0057] The simulation results show that the loading of the low-frequency band feed ridge can effectively realize the small frequency ratio operation of the dual-band common-aperture horn antenna, while having a smaller lateral size to meet the array requirements. The antenna of the technical embodiment of the present invention can meet the requirements of miniaturization of the lateral size and small frequency ratio design of the dual-band common-aperture antenna.

[0058] The above description is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with this technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present invention, and these modifications or replacements should all be included in the scope of protection of the present invention.

Claims

1. A low-frequency-ratio, broadband, dual-frequency, dual-circularly-polarized, coaxial, common-aperture horn antenna unit, characterized in that: include: Low-frequency speaker wall (1), high-frequency speaker wall (2), low-frequency feeding ridge (3), low-frequency dual circular polarization synthesis network (4), coaxial sub-axis (5), high-frequency dual circular polarization synthesis network (6) and high-frequency feeding probe (8); The low-frequency speaker wall (1) is placed on the outside of the high-frequency speaker wall (2), and together they form the side wall of the speaker antenna; The low-frequency feeding ridge (3) is placed between the low-frequency speaker wall (1) and the high-frequency speaker wall (2), and is connected to the low-frequency speaker wall (1); the low-frequency feeding ridge (3) includes four ridges, which are evenly distributed around the central axis of the low-frequency speaker wall (1); the upper half is connected to the side wall of the low-frequency speaker wall (1), and the lower half is an impedance matching section, and there is a gap between the lower half and the side wall of the low-frequency speaker wall (1); The low-frequency dual circular polarization synthesis network (4) is placed below the low-frequency speaker wall (1) and is connected to the low-frequency feed ridge (3) via a coaxial sub-coaxial (5) placed inside the bottom of the low-frequency speaker wall (1); The high-frequency dual circular polarization synthesis network (6) is placed below the high-frequency speaker wall (2) and is connected to the high-frequency speaker wall (2); The high-frequency feeding probe (8) is placed on the side of the high-frequency dual circular polarization synthesis network (6).

2. The low frequency ratio broadband dual-frequency dual-circular polarization coaxial common aperture horn antenna unit according to claim 1, characterized in that: The low-frequency speaker wall (1) is divided into two parts: a bottom surface and a side wall, wherein the upper half of the side wall gradually opens.

3. The low frequency ratio broadband dual-frequency dual-circular polarization coaxial common aperture horn antenna unit according to claim 1, characterized in that: The high-frequency speaker wall (2) is composed only of side walls, excluding the bottom surface, wherein the side walls are divided into a lower half section with a constant diameter and an upper half section that gradually opens.

4. The low frequency ratio broadband dual-frequency dual-circular polarization coaxial common aperture horn antenna unit according to claim 1, characterized in that: The low-frequency dual circular polarization synthesis network (4) is in the shape of a ring structure and is a multi-layer dielectric substrate with four copper surfaces, which is formed by pressing a plurality of dielectric substrates with printed circuits. After passing through the low-frequency dual circular polarization synthesis network (4), the radio frequency signal is divided into four signals with equal amplitude and sequential phases.

5. The low frequency ratio broadband dual-frequency dual-circular polarization coaxial common aperture horn antenna unit according to claim 1, characterized in that: The high-frequency dual circular polarization synthesis network (6) is divided into two parts. One part is a transition section that transmits the radio frequency signal from the circular waveguide section to the rectangular section; the other part is a rectangular waveguide with a side length of 5 and a 5-step step transformation section at the center of the rectangular waveguide to realize the formation of circular polarization of the high-frequency signal.

6. The low frequency ratio broadband dual-frequency dual-circular polarization coaxial common aperture horn antenna unit according to claim 1, characterized in that: It also includes a medium guide rod (7), which is located on the top of the high-frequency speaker wall (2).

7. The low frequency ratio broadband dual-frequency dual-circular polarization coaxial common aperture horn antenna unit according to claim 6, characterized in that: The dielectric guide rod (7) is divided into two parts, the upper part is a radiation section, which is formed into two gradually tapering cones, and the lower part is a 4-order gradually tapering impedance matching section.

Images