LSC frequency band common aperture antenna subarray and design method

Abstract

The invention discloses an LSC frequency band common-caliber antenna subarray and a design method. The LSC frequency band common-caliber antenna subarray is composed of a broadband antenna unit, a frequency divider and a synthesis network. The antenna sub-array is a rectangular uniform array, a rectangular coordinate system is established by taking a geometric center as a center, and the whole antenna sub-array is in axial symmetry. The broadband antenna unit is composed of a dual-linear polarization broadband horn, and the working frequency covers an LSC frequency band. The frequency divider is composed of two channel filters, and band-pass filtering of the LS frequency band and the C frequency band is achieved. And the synthesis network completes radio frequency signal switching transition of the LS frequency band and the C frequency band and synthesizes left and right-hand circular polarization. According to the LSC frequency band common-caliber antenna subarray and the design method, the working performance of each frequency band of a common-caliber antenna can be effectively ensured, the design difficulty of the array is simplified, and the processing implementation difficulty of the common-caliber antenna is reduced. Based on the antenna sub-array, a large-scale multi-band common-aperture array can be quickly spliced.

Description

Technical Field

[0001] The present invention belongs to the field of antenna technology, and in particular relates to an LSC frequency band common aperture antenna subarray and a design method. Background Art

[0002] Phased array antennas can quickly scan beams by independently controlling the amplitude and phase of the radiating elements, and are widely used in radar, communications, measurement and control, and other fields. The rapid development of wireless communications has put forward higher requirements for antenna systems, mainly in terms of multi-band, common aperture, multi-polarization, and miniaturization. Multi-band common aperture antennas can reasonably design multiple antennas with different operating frequencies and polarization characteristics within the same aperture, while ensuring the working performance of antennas in each frequency band, achieving a compact antenna structure and effectively improving the space utilization of the platform. Therefore, the performance of multi-frequency and multi-polarization operation is the future development trend of wireless communication antennas.

[0003] According to publicly available literature, the research on shared-aperture multi-band antenna arrays is still focused on the aperture sharing of dual-band dual-polarization arrays. The doctoral dissertation "Multi-band Dual-Polarization Shared-Aperture Microstrip Antenna Array" of Shanghai University details and introduces the methods for realizing dual-band common-aperture antennas, mainly including four methods: low / high frequency sparse array combination, interleaved structure, open patch structure, and stacked structure. Each method has its own characteristics and can meet the requirements of specific working scenarios. The first low / high frequency sparse array combination structure is actually a quasi-shared-aperture solution. It can achieve an approximate shared-aperture dual-frequency array face economically under specific index requirements, but the sidelobe level of the peripheral frequency band will deteriorate and it is difficult to expand into a large array face based on this configuration. The second interleaved structure can be applied to the common-aperture design of any frequency ratio, but the disadvantage is that the low-frequency percentage bandwidth is relatively narrow. The third open patch structure has a lower profile, which is conducive to conformal or antenna folding / unfolding, but the adjustment of the frequency ratio is more difficult than the interleaved structure, and its applicability under odd and non-integer frequency ratios remains to be determined. The low-frequency unit of the fourth stacked structure does not require holes, the low-frequency antenna bandwidth is wider, and the isolation between low and high frequency antennas is better. However, the feeding structure of the upper antenna causes the radiation environment of the lower antenna to be destroyed, causing the antenna performance to deteriorate, and this method makes the overall cross-section of the antenna higher. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems of the prior art and disclose an LSC frequency band common aperture antenna subarray and a design method, taking into account the performance of each frequency band, engineering feasibility and design efficiency.

[0005] On the one hand, the purpose of the present invention is achieved by the following technical solutions:

[0006] An LSC frequency band common aperture antenna subarray, the LSC frequency band common aperture antenna subarray comprising: a broadband antenna unit, a frequency divider and a synthesis network;

[0007] The broadband antenna unit is composed of a broadband speaker, and the operating frequency covers the LSC frequency band; the frequency divider is composed of a two-channel filter to achieve bandpass filtering of the LS frequency band and the C frequency band; the synthesis network completes the radio frequency signal switching transition of the LS frequency band and the C frequency band and forms left-right circular polarization.

[0008] According to a preferred embodiment, the antenna subarray is a rectangular uniform array composed of N×N broadband antenna units, where N≥4, N∈2 n , n∈[2,3,4,…], a rectangular coordinate system is established with the geometric center, and the entire antenna subarray is evenly divided into four quadrants. Each quadrant contains P broadband antenna units, and each quadrant is axisymmetric, where P=N×N / 4.

[0009] According to a preferred embodiment, the broadband horn is a dual-line polarization horn having a vertical polarization feed port and a horizontal polarization feed port.

[0010] According to a preferred embodiment, the broadband horn is not limited to being in the form of a ridge horn antenna.

[0011] According to a preferred embodiment, a frequency divider is respectively provided at the vertical polarization feed port and the horizontal polarization feed port of the broadband horn antenna;

[0012] The frequency divider consists of a common antenna port, an LS band port and a C band port;

[0013] The common antenna port is connected to the vertical polarization feed port or the horizontal polarization feed port of the broadband speaker through a KK connector.

[0014] According to a preferred embodiment, the synthetic network is a square structure, which can be divided into an antenna interface surface, a component interface surface and an internal stripline network.

[0015] According to a preferred embodiment, the internal stripline network is divided into an LS band synthesis network and a C band synthesis network according to frequency band;

[0016] The LS-band synthesis network completes the synthesis of the passive RF signals of the M broadband antenna units in each quadrant and then forms a left-handed circularly polarized signal; the C-band synthesis network completes the formation of the left-handed circularly polarized signal of each broadband antenna unit in each quadrant;

[0017] in M≥4,M∈2 n,n∈[2,3,4,…], C0 represents the center frequency of the C band, S0 represents the center frequency of the S band, and [] represents rounding down.

[0018] According to a preferred embodiment, the antenna interface plane has a total of 8P LS band interfaces and 8P C band interfaces;

[0019] The component interface surface has a total of P LS-band left-hand interfaces, P LS-band right-hand interfaces, 4P C-band left-hand interfaces and 4P C-band right-hand interfaces.

[0020] According to a preferred implementation, the LS band interface is connected to the LS band port of the frequency divider via a KK connector; and the C band interface is connected to the C band port of the frequency divider via a KK connector.

[0021] On the other hand, the present invention also discloses:

[0022] A method for designing a co-aperture antenna subarray in an LSC frequency band is disclosed. The method for designing a co-aperture antenna subarray in an LSC frequency band is used to design the co-aperture antenna subarray in the LSC frequency band into the aforementioned co-aperture antenna subarray structure.

[0023] The aforementioned main scheme of the present invention and its further options can be freely combined to form multiple schemes, all of which are schemes that can be adopted and claimed for protection by the present invention. After understanding the scheme of the present invention, those skilled in the art can understand that there are multiple combinations based on the prior art and common knowledge, all of which are technical schemes to be protected by the present invention, and they are not exhaustively listed here.

[0024] Beneficial effects of the present invention:

[0025] (1) High design efficiency and strong frequency band applicability. The present invention uses a broadband antenna unit to realize the reception and transmission of radio frequency signals in multiple frequency bands and can be compatible with any frequency band with the help of a frequency divider. There is no need to design multiple antennas together, which reduces the complex and time-consuming comprehensive optimization of arrays in different frequency bands. It does not need to rely on high computing resources, and there is no need to re-optimize after changes in the operating frequency, array aperture, array element spacing, etc., which greatly improves the design efficiency.

[0026] (2) Better engineering feasibility. Compared with the traditional common aperture design methods: low / high frequency sparse array combination, interlaced structure, open patch structure and stacked structure, the broadband antenna unit combined with the frequency divider avoids the complex assembly and implementation processes such as mutual interference and interconnection of multiple antenna structures.

[0027] (3) It has better scalability. By passively synthesizing four units in the LS band synthesis network, a unit spacing (electrical size) similar to that of the C band unit can be obtained. By using this antenna subarray as the basic particle, an array form of any scale can be obtained, and it can be ensured that under the same array configuration, the low and high frequency sidelobe and grating lobe capabilities are approximately equal. The subarray is modularly designed with a single and unified feeding type, which is very conducive to the realization of large-scale arrays in engineering.

[0028] (4) The antenna performance of each frequency band can be taken into account. The present invention adopts a broadband antenna unit to realize the transmission and reception of radio frequency signals of multiple frequency bands and can realize the operation of any frequency band with the help of a frequency divider, and the radiation performance of each frequency band can be guaranteed by a single broadband antenna. It avoids the deterioration or even distortion of the directional pattern caused by the mutual coupling and stacking of the traditional co-aperture design antennas. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a rectangular arrangement diagram of the LSC frequency band common aperture antenna subarray of the present invention;

[0030] Figure 2 This is a schematic diagram of the design principle of the LSC frequency band common aperture antenna subarray of the present invention;

[0031] Figure 3 This is a diagram of an embodiment of a LSC frequency band common aperture antenna subarray of the present invention;

[0032] Figure 4 This is a diagram showing an embodiment of a broadband antenna unit in a LSC frequency band common aperture antenna subarray of the present invention;

[0033] Figure 5 This is a diagram showing an embodiment of a frequency divider in a LSC frequency band common aperture antenna subarray of the present invention;

[0034] Figure 6 It is a diagram showing an embodiment of a component interface surface and an internal stripline network in a LSC frequency band common aperture antenna subarray of the present invention;

[0035] Figure 7 This is a diagram showing an embodiment of the antenna interface surface in the LSC frequency band common aperture antenna subarray of the present invention;

[0036] Figure 8 It is an internal diagram of the C-band synthesis network in the LSC-band common-aperture antenna subarray of the present invention;

[0037] Fig. 9 It is an internal diagram of the LS frequency band synthesis network in the LSC frequency band common aperture antenna subarray of the present invention;

[0038] Fig.10 It is a synthetic network interface surface diagram in the LSC frequency band common aperture antenna subarray of the present invention;

[0039] Fig.11 This is a diagram of the interface of the synthetic network components in the LSC frequency band common aperture antenna subarray of the present invention. DETAILED DESCRIPTION

[0040] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0041] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0042] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0043] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0044] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In addition, the present invention should be pointed out that, in the present invention, unless the specific structure, connection relationship, positional relationship, power source relationship, etc. are specifically written out, the structure, connection relationship, positional relationship, power source relationship, etc. involved in the present invention are all known by those skilled in the art on the basis of the prior art without creative work.

[0046] Example 1

[0047] In this embodiment, the selected LSC frequency bands are 1.5-2 GHz, 2-4 GHz, and 4-8 GHz. The center frequency of the C band is C0 = 6 GHz, and the center frequency of the S band is S0 = 3 GHz. [] indicates rounding down.

[0048] See also Figure 1 . The LSC band common-aperture antenna subarray of the present invention is selected as a rectangular uniform array composed of N×N broadband antenna units (N is 4), and a 4×4 rectangular uniform array is obtained. The unit spacing is selected as d0=2λ, λ is the wavelength corresponding to the C band, and the side length of the subarray is L=8λ. The antenna unit can select a broadband ridge horn antenna and its deformation form, and the operating frequency covers the LSC band. A rectangular coordinate system is established with the geometric center, and the entire antenna subarray is evenly divided into four quadrants, each quadrant contains P=4 broadband antenna units (P=N×N / 4=4), and each quadrant is axisymmetric.

[0049] See also Figure 2 The design principle of the LSC frequency band common aperture antenna subarray of the present invention is as follows: Figure 2 The antenna subarray consists of a broadband antenna unit 1, a frequency divider 2 and a synthesis network 3.

[0050] Taking the reception of a local subarray consisting of four array elements as an example, the broadband LSC frequency band RF signal is received by the broadband antenna unit 1 to form a vertical polarization signal V and a horizontal polarization signal H, and enters the frequency divider 2 through the two feed ports of vertical polarization and horizontal polarization respectively.

[0051] Frequency divider 2 is composed of two-channel filters to realize bandpass filtering of LS band and C band, that is, the vertical polarization signal V forms LS band vertical polarization signal LS_V and C band vertical polarization signal C_V after passing through the frequency divider; the horizontal polarization signal H forms LS band horizontal polarization signal LS_H and C band horizontal polarization signal C_H after passing through the frequency divider.

[0052] The synthesis network 3 completes the RF signal switching transition between the LS band and the C band and forms left-hand circular polarization. The four vertical polarization signals LS_V formed by the four units after the frequency divider 2 are first synthesized by the synthesis network 3 to obtain the vertical polarization signal LS_V_1, and the four horizontal polarization signals LS_H formed by the four units after the frequency divider 2 are first synthesized by the synthesis network 3 to obtain the horizontal polarization signal LS_H_1. The synthesized vertical polarization signal LS_V_1 and the horizontal polarization signal LS_H_1 pass through the LS bridge in the synthesis network 3 to form the LS band right-hand circular polarization signal LS_R and the LS band left-hand circular polarization signal LS_L.

[0053] The C-band vertical polarization signal C_V and horizontal polarization signal C_H formed by each unit after the frequency divider 2 are switched by the synthesis network 3 and then enter the C bridge for synthesis to obtain the C-band right-hand circular polarization signal C_R and the C-band left-hand circular polarization signal C_L.

[0054] See also Figure 3 . Figure 3 This is a diagram of an embodiment of the LSC frequency band common aperture antenna subarray of the present invention. The antenna subarray is composed of a broadband antenna unit 1, a frequency divider 2 and a synthesis network 3. The broadband antenna unit is composed of a broadband horn, and the operating frequency covers the LSC frequency band.

[0055] See also Figure 4 . Figure 4 This is a diagram of an embodiment of a broadband antenna unit in a common aperture antenna subarray of the LSC frequency band of the present invention. The broadband horn is a dual-line polarization horn having a vertical polarization feed port 4 and a horizontal polarization feed port 5. The horn antenna has a height of 5λ and a horn aperture of 2λ.

[0056] See also Figure 5 . Figure 5 The figure is an embodiment of the frequency divider in the LSC frequency band common aperture antenna subarray of the present invention. The frequency divider is composed of a common antenna port 6, a LS frequency band port 7 and a C frequency band port 8. The common antenna port 6 is blindly connected with the vertical polarization feed port 4 or the horizontal polarization feed port 5 in the broadband antenna unit 1.

[0057] See also Figure 7 and Figure 8 . Figure 7 and Figure 8 The synthetic network is a square structure, which can be divided into an antenna interface surface ( Figure 8 ), component interface surfaces, and internal stripline networks ( Figure 7 ).

[0058] See also Figure 8 and Fig. 9 . Figure 8 and Fig. 9The internal diagram of the synthesis network in the LSC frequency band common aperture antenna subarray of the present invention. The internal stripline network can be divided into LS frequency band synthesis network ( Fig. 9 ) and C-band synthesis network ( Figure 8 ). The LS band synthesis network completes the synthesis of the passive RF signals of M = 4 units in each quadrant and then forms a left-handed circular polarization signal. The C band synthesis network completes the formation of the left-handed circular polarization signal of each unit in each quadrant.

[0059] See also Fig.10 . Fig.10 The composite network antenna interface surface diagram in the LSC frequency band common aperture antenna subarray of the present invention. The antenna interface surface has 8P=32 LS frequency band interfaces 9 and 8P=32 C frequency band interfaces 10. The LS frequency band interface 9 is connected to the LS frequency band port 7 of the frequency divider through a KK connector. The C frequency band interface 10 is connected to the C frequency band port 8 of the frequency divider through a KK connector.

[0060] See also Fig.11 . Fig.11 The composite network component interface surface diagram of the LSC frequency band common aperture antenna subarray of the present invention. The component interface surface has P=4 LS frequency band left-handed interfaces 11, P=4 LS frequency band right-handed interfaces 12, 4P=16 C frequency band left-handed interfaces 13 and 4P=16 C frequency band right-handed interfaces 14.

[0061] The present invention adopts a broadband antenna unit to realize the reception and transmission of radio frequency signals in multiple frequency bands and can be compatible with any frequency band with the help of a frequency divider. There is no need to carry out co-design of multiple antennas, which reduces the complex and time-consuming comprehensive optimization of arrays in different frequency bands. It does not need to rely on higher computing resources, and there is no need to re-optimize after changes in operating frequency, array aperture, array element spacing, etc., which greatly improves the design efficiency.

[0062] Compared with traditional co-aperture design methods: low / high frequency sparse array combination, interleaved structure, open patch structure and stacked structure, the broadband antenna unit combined with the frequency divider avoids the complex assembly and implementation processes such as mutual interference and interconnection of multiple antenna structures.

[0063] By passively synthesizing four units in the LS band synthesis network, a unit spacing (electrical size) similar to that of the C band unit can be obtained. By using this antenna subarray as a basic particle, an array of any size can be obtained, and it can be ensured that the low and high frequency sidelobe and grating lobe capabilities are approximately equal under the same array configuration. The modular design of the subarray and the single and unified feeding type are very conducive to the realization of large-scale arrays in engineering.

[0064] The present invention adopts a broadband antenna unit to realize the transmission and reception of radio frequency signals in multiple frequency bands and can realize the operation of any frequency band with the help of a frequency divider, and the radiation performance of each frequency band can be guaranteed by a single broadband antenna. It avoids the deterioration or even distortion of the directional pattern caused by the mutual coupling and stacking of the traditional co-aperture design antennas.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A common aperture antenna subarray in the LSC frequency band, characterized in that: The LSC frequency band common aperture antenna subarray comprises: a broadband antenna unit (1), a frequency divider (2) and a synthesis network (3); The broadband antenna unit (1) is composed of a broadband speaker, and its operating frequency covers the LSC frequency band; the frequency divider (2) is composed of a two-channel filter, which realizes the bandpass filtering of the LS frequency band and the C frequency band; the synthesis network (3) completes the radio frequency signal switching transition of the LS frequency band and the C frequency band and forms left-right circular polarization.

2. The LSC frequency band common aperture antenna subarray according to claim 1, characterized in that: The antenna subarray is a rectangular uniform array consisting of N×N broadband antenna units, where N≥4, N∈2 n , n∈[2,3,4,…], A rectangular coordinate system is established with the geometric center, and the entire antenna subarray is evenly divided into four quadrants. Each quadrant contains P broadband antenna units, and each quadrant is axially symmetric, where P = N × N / 4.

3. The LSC frequency band common aperture antenna subarray according to claim 1, characterized in that: The broadband horn is a dual-line polarization horn having a vertical polarization feed port (4) and a horizontal polarization feed port (5).

4. The LSC frequency band common aperture antenna subarray according to claim 3, characterized in that: The broadband horn is not limited to being in the form of a ridge horn antenna.

5. The LSC frequency band common aperture antenna subarray according to claim 3, characterized in that: A frequency divider (2) is respectively provided at the vertical polarization feed port (4) and the horizontal polarization feed port (5) of the broadband horn antenna; The frequency divider (2) is composed of a common antenna port (6), an LS frequency band port (7) and a C frequency band port (8); The common antenna port (6) is connected to the vertical polarization feed port (4) or the horizontal polarization feed port (5) of the broadband speaker via a KK connector.

6. The LSC frequency band common aperture antenna subarray according to claim 5, characterized in that: The synthetic network (3) is a square structure and can be divided into an antenna interface surface, a component interface surface and an internal stripline network.

7. The LSC frequency band common aperture antenna subarray according to claim 6, characterized in that: The internal stripline network is divided into an LS band synthesis network and a C band synthesis network according to the frequency band; The LS-band synthesis network completes the synthesis of the passive RF signals of the M broadband antenna units in each quadrant and then forms a left-handed circularly polarized signal; the C-band synthesis network completes the formation of the left-handed circularly polarized signal of each broadband antenna unit in each quadrant; in M≥4,M∈2 n ,n∈[2,3,4,…], C0 represents the center frequency of the C band, S0 represents the center frequency of the S band, and [] represents rounding down.

8. The LSC frequency band common aperture antenna subarray according to claim 7, characterized in that: The antenna interface surface has a total of 8P LS frequency band interfaces (9) and 8P C frequency band interfaces (10); The component interface surface has a total of P LS-band left-hand interfaces (11), P LS-band right-hand interfaces (12), 4P C-band left-hand interfaces (13) and 4P C-band right-hand interfaces (14).

9. The LSC frequency band common aperture antenna subarray according to claim 8, characterized in that: The LS band interface (9) is connected to the LS band port (7) of the frequency divider via a KK connector; and the C band interface (10) is connected to the C band port (8) of the frequency divider via a KK connector.

10. A method for designing a common-aperture antenna subarray in an LSC frequency band, characterized in that: The LSC frequency band co-aperture antenna subarray is designed into the LSC frequency band co-aperture antenna subarray structure as described in any one of claims 1 to 9 through the LSC frequency band co-aperture antenna subarray design method.

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