Heterogeneous antenna combination for improving limited large array synthesis gain and determination method

Abstract

The invention discloses a heterogeneous antenna combination for improving limited large array synthesis gain and a determination method. The scale of an array antenna is N rows * M columns; the heterogeneous antenna combination comprises the following four types of functional antenna units: core radiation units which are deployed in an internal area of an array antenna, and all the core radiation units are in the same mutual coupling environment in an array, so that the core radiation units have basically consistent unit directional diagrams; the feed port of the core radiation unit is directly connected with the rear-end transmit-receive assembly. The E-plane correction radiation units are arranged on two symmetrical side columns of the array antenna, and the unit directional diagrams of the E-plane correction radiation units are equivalent to those of the core radiation unit; a feed port of the E-plane correction radiation unit is directly connected with the rear-end transceiving component; the H-plane load units are arranged on the other two end edge rows of the array antenna; and the corner load units are deployed at four corner points of the array. The method is suitable for an array application scene which is limited by space and cannot be expanded on a large scale.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of array antennas, and particularly relates to a heterogeneous antenna combination and determination method for improving the synthetic gain of a limited large array. BACKGROUND

[0002] Array antennas have been widely used in many fields such as radars and communications due to their flexible beamforming capability. The gain synthesis of traditional array antennas depends on an array composed of isotropic antenna elements. The classical expression of the array synthetic gain G is G = Ga + 10log(N), where Ga represents the antenna element gain, and N represents the total number of antenna elements. It is worth noting that a key prerequisite for this formula to hold is that all antenna elements in the array have isotropic radiation characteristics and are completely consistent in performance.

[0003] However, in actual applications, mutual coupling effects exist among array antenna elements. Due to the spacing between elements and the limitation of array geometry, the intensity of mutual coupling experienced by elements at different positions differs. This leads to the fact that the directional patterns and gain characteristics of array elements are not completely identical, especially for antenna elements located at the edges of the array, whose directional patterns exhibit significant distortion and main lobe shift (head bias phenomenon) compared to elements at the center of the array, and their normal gain is significantly lower than that of the center elements. The above non-ideal characteristics will weaken the overall synthetic gain performance of the array. Although increasing the array size can effectively dilute the negative impact of gain degradation of edge elements on the total gain, in small array or limited element number application scenarios, the mutual coupling effect still has a significant and non-negligible impact on the array gain. SUMMARY

[0004] The present application aims to solve the problem of reduced synthetic gain caused by mutual coupling effects in limited large array antennas, and proposes a heterogeneous antenna combination and determination method for improving the synthetic gain of a limited large array.

[0005] The present application provides a heterogeneous antenna combination for improving the synthetic gain of a limited large array. The size of the array antenna corresponding to the limited large array is N rows x M columns. The position of the array element constituting the array antenna is uniquely identified by its row number i and column number j. Wherein, 1≤i≤N; 1≤j≤M; the polarization direction of the antenna is along the array row direction, i.e. the antenna E plane is parallel to the array antenna row direction, and the H plane is parallel to the array antenna column direction.

[0006] The heterogeneous antenna combination includes the following four types of functionalized antenna elements:

[0007] Core radiation units: deployed in the inner region of the array antenna, i.e. 2≤i≤N-1 and 2≤j≤M-1; all core radiation units are in the same mutual coupling environment in the array, thus having substantially consistent unit patterns; as the main radiation units, the feeding ports of the core radiation units are directly connected to the backend transceiver assembly;

[0008] E-plane correction radiation units: deployed in the two side columns of the array antenna, i.e. 2≤i≤N-1, j=1 and j=M; the E-plane correction radiation units are located at the E-plane edges of the array, and the mutual coupling environment is different from that of the core radiation units, and the unit pattern produces main lobe deviation; in view of the mutual coupling effect, the E-plane correction radiation units are designed on the basis of the structure of the core radiation units, and the unit pattern of the optimized E-plane correction radiation units is equivalent to that of the core radiation units; the feeding ports of the E-plane correction radiation units are directly connected to the backend transceiver assembly;

[0009] H-plane load units: deployed in the other two end rows of the array antenna, and adjacent to the E-plane correction radiation units, i.e. i=1 and i=N, and 2≤j≤M-1; the H-plane load units have the same structure as the core radiation units, and the feeding ports are connected to 50-ohm loads;

[0010] Corner load units: deployed at the four corner points of the array, i.e. the position coordinates satisfy i=1, j=1, i=1, j=M, i=N, j=1, and i=N, j=M; the corner load units have the same structure as the E-plane correction radiation units; the feeding ports of the corner load units are connected to 50-ohm loads.

[0011] Further, if the mutual coupling strength between the edge units in the H-plane direction of the array, i.e. the column direction, is lower than -20dB, the H-plane load units and the corner load units are removed as appropriate, so as to simplify the structure;

[0012] If the array antenna is a one-dimensional array, only the E-plane correction radiation units are included.

[0013] Further, the antenna combination is suitable for various types of antenna structures.

[0014] Further, N≤16 and M≤16.

[0015] The application also provides a method for determining a heterogeneous antenna combination for improving the synthetic gain of a limited large array, the method being used for determining the antenna combination provided by the application, and the method comprising:

[0016] Step 1: according to the basic requirements of array design, such as gain, beamwidth, etc., a conventional homogeneous array is designed, and the array size and unit form are determined;

[0017] Step 2: the mutual coupling coefficient S of the H-plane edge units of the array is obtained through electromagnetic simulation software simulation;

[0018] Step 3: if S<-20dB, then the array is partitioned, and the corresponding heterogeneous units are designed respectively, including four types of functional antenna units; if S21>-20dB, then the H-plane load unit and the corner load unit are removed, and only the design of the E-plane correction radiation unit is carried out;

[0019] Step 4: the E-plane correction radiation unit pattern and the core radiation unit pattern are extracted, and the E-plane correction radiation unit is designed through the unit radiation structure asymmetric design method, so that the gain difference of the unit pattern within the range of ±60° is within 1dB;

[0020] Step 5: the heterogeneous array combination is completed according to the structure form of the antenna combination, simulation is completed, and the final performance of the array is obtained.

[0021] Compared with the prior art, the significant progress of the present application is that:

[0022] Compared with the traditional single-structure homogeneous array antenna design, the "head deviation" phenomenon caused by the difference in mutual coupling environment is eliminated by designing a special optimization unit for the E-plane edge of the array, and the E-plane edge unit radiation performance is consistent with the core radiation unit; the combination of the E-plane correction radiation unit and the boundary load unit maximizes the recovery of the overall synthesis gain of the array lost due to the mutual coupling effect, and is particularly suitable for array application scenarios that are limited by space and cannot be expanded on a large scale.

[0023] To more clearly illustrate the functional characteristics and structural parameters of the present application, the following further describes the present application in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a heterogeneous antenna combination for improving the synthesis gain of a limited large array.

[0025] Figure 2 It is a schematic diagram of a traditional limited large homogeneous array antenna.

[0026] Figure 3 It is a schematic diagram of an embodiment of a heterogeneous antenna combination for improving the synthesis gain of a limited large array.

[0027] Figure 4 It is a schematic diagram of a core radiation unit and an E-plane correction radiation unit (including left and right units) of an embodiment of a heterogeneous antenna combination for improving the synthesis gain of a limited large array.

[0028] Figure 5 is a diagram of the pattern of each antenna unit of a conventional limited large homogeneous array antenna at each frequency point; wherein Figure 5(a) is f L , Figure 5(b) is 1.5f L , and Figure 5(c) is 2f L ;

[0029] Figure 6 is a diagram of the directional pattern of each antenna unit at each frequency point in a heterogeneous antenna combination method for improving the synthetic gain of a limited large array of the present application; Figure 6(a) is f L , Figure 6(b) is 1.5f L , Figure 6(c) is 2f L ;

[0030] Figure 7 Figure 7 is a diagram of the synthetic gain of an embodiment of the present application compared with the gain of a conventional homogeneous array. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0032] In combination Figure 1 , a heterogeneous antenna combination limited large array antenna has a size of N rows by M columns. The position of an array unit is uniquely identified by its row number i (1≤i≤N) and column number j (1≤j≤M). The polarization direction of the antenna is along the array row direction, that is, the E plane of the antenna is parallel to the array row direction, and the H plane is parallel to the array column direction.

[0033] The heterogeneous antenna combination method includes the following four types of functionalized antenna units:

[0034] Core radiation unit: deployed in the internal region of the array (i.e., at positions where 2≤i≤N-1 and 2≤j≤M-1). All core radiation units are in the same mutual coupling environment in the array, and thus have substantially consistent unit directional patterns. As the main radiation unit, its feed port is directly connected to the back-end transceiver component.

[0035] E-plane correction radiation unit: deployed on the left and right side columns of the array (i.e., at positions where 2≤i≤N-1, j=1, and j=M). These units are located at the E-plane edge of the array, and their mutual coupling environment is different from that of the core radiation unit, and their unit directional pattern produces main lobe shift. In view of the above mutual coupling effect, the core radiation unit is optimized based on the basic structure, so that the optimized unit directional pattern is equivalent to that of the core radiation unit. Its feed port is directly connected to the back-end transceiver component.

[0036] H-plane load unit: deployed on the top and bottom end rows of the array (i.e., at positions where i=1 and i=N, and 2≤j≤M-1). Its physical structure is the same as that of the core radiation unit, except that its feed port is connected to a 50-ohm load.

[0037] Corner loading unit: deployed in the four corner points of the array, namely the position: (i=1, j=1), (i=1, j=M), (i=N, j=1), (i=N, j=M). Its physical structure is the same as that of the edge correction radiation unit. The difference is that its feed port is connected to a 50-ohm load.

[0038] Further, if the mutual coupling strength between the edge units in the H-plane direction (i.e. the column direction) of the array is lower than -20dB, the H-plane loading unit and the corner loading unit can be removed as appropriate to simplify the structure. If the array is a one-dimensional array, only the design of the E-plane correction radiation unit is performed.

[0039] Further, the present heterogeneous antenna combination is theoretically applicable to various types of antenna structures.

[0040] Further, the N≤16, M≤16.

[0041] Further, the determination method of the heterogeneous antenna combination is as follows:

[0042] Step 1: according to the basic requirements of array design such as gain, beamwidth, etc., conventional homogeneous array design is carried out to determine the array size, unit form, etc.

[0043] Step 2: obtain the mutual coupling coefficient S of the H-plane edge unit of the array through electromagnetic simulation software simulation;

[0044] Step 3: if S<-20dB, according to claim 1, the array is partitioned and the corresponding heterogeneous units are designed; if S21≥-20dB, according to claim 2, the H-plane loading unit and the corner loading unit are removed and only the design of the E-plane correction radiation unit is carried out;

[0045] Step 4: extract the E-plane unit pattern of the edge unit and the E-plane pattern of the unit in the array, and complete the design of the E-plane correction radiation unit through unit radiation structure asymmetric design and other methods, so that the gain difference of the unit pattern within ±60° is within 1dB.

[0046] Step 5: complete the heterogeneous array assembly according to claim 1, complete the simulation, and obtain the final performance of the array.

[0047] Example 1

[0048] The present embodiment provides a heterogeneous antenna combination method for improving the synthesis gain of a limited large array. Figure 2 The traditional homogeneous array antenna is a Vivaldi antenna fed by a microstrip line, the array size is 8×8, and the unit size is 22.5mm. Figure 3 The traditional homogeneous array is designed into a heterogeneous array according to the present application. Figure 2 The traditional homogeneous array is designed into a heterogeneous array according to the present application. The present embodiment provides a heterogeneous antenna combination method for improving the synthesis gain of a limited large array.

[0049] Through simulation, the coupling coefficient S of the edge unit of the traditional homogeneous array in H plane is less than -20dB. Therefore, only the E-plane correction unit is designed.

[0050] Figure 4 For the E-plane correction radiation unit, on the basis of the basic structure of the core radiation unit, an asymmetric radiation structure is adopted, one side of the radiation slot is designed as a low profile, and the edge is rectangularly slotted to make the edge current gather to the radiation slot.

[0051] Figure 5 is a comparison of the directional patterns of each unit of the traditional homogeneous array antenna. It can be seen that the peripheral unit is affected by the mutual coupling effect, the directional pattern of the unit is deflected, and the maximum gain of the peripheral unit is not in the normal direction.

[0052] As shown in Figure 6, the directional patterns of each unit of the heterogeneous array of the embodiment are compared. It can be seen that the directional patterns of all units are basically the same, and the maximum gain is in the normal direction.

[0053] As Figure 7 The comparison of the array gain of the simulation of the heterogeneous array of the embodiment and the array gain of the traditional homogeneous array shows that the array gain is improved by about 0.9dB.

[0054] The embodiment described in the application is only proposed as an implementation form of a heterogeneous antenna combination method for improving the synthesis gain of a limited array, and the related description is illustrative rather than limiting. Therefore, those skilled in the art can make other specific implementation operations according to the design idea in the claims of the application, make various changes in form and details without creative labor on the premise of not departing from the spirit and scope of the application defined by the appended claims, and the above should be regarded as the design range of the application.

[0055] Although the embodiments of the application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the application, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. A heterogeneous antenna combination for improving the combined gain of a finite large array, characterized in that, The finite array corresponds to an array antenna with a size of N rows × M columns; the position of the array element constituting the array antenna is uniquely identified by its own row number i and column number j; where 1≤i≤N; 1≤j≤M; the antenna polarization direction is along the array row direction, that is, the antenna E plane is parallel to the array antenna row direction, and the H plane is parallel to the array antenna column direction. Heterogeneous antenna assemblies include the following four types of functionalized antenna elements: Core radiating element: Deployed in the internal region of the array antenna, i.e., the position where 2≤i≤N-1 and 2≤j≤M-1; All core radiating elements are in the same mutual coupling environment in the array, and therefore have basically the same element radiation pattern; As the main radiating element, the feed port of the core radiating element is directly connected to the back-end transceiver component. E-plane corrected radiating element: Deployed on both sides of the symmetrical array antenna, i.e., at positions where 2≤i≤N-1, j=1 and j=M; The E-plane corrected radiating element is located at the edge of the array's E-plane, and its mutual coupling environment is different from that of the core radiating element. The optimized E-plane corrected radiating element's radiation pattern is equivalent to that of the core radiating element; The feed port of the E-plane corrected radiating element is directly connected to the back-end transceiver components. H-plane load element: Deployed at the other two ends of the array antenna, forming adjacent sides with the E-plane correction radiation element, i.e., positions where i=1 and i=N, and 2≤j≤M-1; the structure of the H-plane load element is the same as that of the core radiation element, and the feed port is connected to a 50-ohm load. Corner load cells: Deployed at the four corners of the array, i.e., the position coordinates satisfy i=1, j=1, i=1, j=M, i=N, j=1, i=N, j=M; the structure of the corner load cells is the same as that of the E-plane correction radiation cells; the feed port of the corner load cells is connected to a 50-ohm load.

2. The heterogeneous antenna combination for improving the combined gain of a finite large array according to claim 1, characterized in that, If the mutual coupling strength between edge elements in the H-plane direction (i.e., column direction) of the array is less than -20dB, then the H-plane load element and the corner load element do not exist. If the array antenna is a one-dimensional array, it only includes E-plane corrected radiation elements.

3. A heterogeneous antenna combination for improving the combined gain of a finite large array according to claim 1, characterized in that, The N≤16, M≤16.

4. A method for determining heterogeneous antenna combinations to improve the combined gain of a finite large array, the method being used to determine any antenna combination according to claims 1 to 3, characterized in that, The method includes: Step 1: Based on the basic requirements of array design, including gain and bandwidth, carry out conventional isomorphic array design to determine the array size and cell type; Step 2: Obtain the mutual coupling coefficient S of the edge elements of the H-plane of the array through electromagnetic simulation software; Step 3: If S < -20dB, the array is divided into partitions, and corresponding heterogeneous units are designed for each partition, including four types of functional antenna units; if S21 ≥ -20dB, the H-plane load unit and the corner load unit are removed, and only the E-plane corrected radiation unit is designed. Step 4: Extract the radiation pattern of the E-plane corrected radiation element and the radiation pattern of the core radiation element. Complete the design of the E-plane corrected radiation element by using the asymmetric design method of the element radiation structure, so that the gain difference of the element radiation pattern within ±60° is within 1dB. Step 5: Complete the heterogeneous array assembly according to the structure of the antenna combination, complete the simulation, and obtain the final performance of the array.

Images